Merge branch 'master' into refactor/ci-config-move-job-entries

* master: (522 commits)
  Fix CI yaml example
  Align cancel and retry buttons
  Remove deploy to production button
  Fix a bug where the project's repository path was returned instead of the wiki path
  Don't fail to highlight when Rouge doesn't have a lexer
  Revert "Merge branch 'gl-dropdown-issuable-form' into 'master'"
  Update tests
  Don't fail when Ci::Pipeline doesn't have a project
  Don't fail when a LegacyDiffNote didn't store the right diff
  Update CHANGELOG
  Use cattr_accessor instead duplicating code on NoteOnDiff concern
  Fix mentioned users list on diff notes
  Don't ask Heather to review documentation MR's
  add project name and namespace to filename on project export
  navbar_icon was renamed to custom_icon in:
  use %(...) and %[...] in favor of %<...>
  Fix spec Don't attempt to disable statement timeout on a MySQL DB
  Disable statement timeout outside of transaction and during adding concurrent index
  Disable PostgreSQL statement timeout during migrations
  Add visibility icon
  ...

35 files changed, 2992 insertions, 71 deletions

diff --git a/spec/lib/banzai/filter/blockquote_fence_filter_spec.rb b/spec/lib/banzai/filter/blockquote_fence_filter_spec.rb
new file mode 100644
index 00000000000..2799249ae3e
--- /dev/null
+++ b/spec/lib/banzai/filter/blockquote_fence_filter_spec.rb
@@ -0,0 +1,14 @@
+require 'rails_helper'
+
+describe Banzai::Filter::BlockquoteFenceFilter, lib: true do
+  include FilterSpecHelper
+
+  it 'converts blockquote fences to blockquote lines' do
+    content = File.read(Rails.root.join('spec/fixtures/blockquote_fence_before.md'))
+    expected = File.read(Rails.root.join('spec/fixtures/blockquote_fence_after.md'))
+
+    output = filter(content)
+
+    expect(output).to eq(expected)
+  end
+end
diff --git a/spec/lib/banzai/filter/label_reference_filter_spec.rb b/spec/lib/banzai/filter/label_reference_filter_spec.rb
index f1064a701d8..9276a154007 100644
--- a/spec/lib/banzai/filter/label_reference_filter_spec.rb
+++ b/spec/lib/banzai/filter/label_reference_filter_spec.rb
@@ -93,8 +93,8 @@ describe Banzai::Filter::LabelReferenceFilter, lib: true do
     end
 
     it 'links with adjacent text' do
-      doc = reference_filter("Label (#{reference}.)")
-      expect(doc.to_html).to match(%r(\(<a.+><span.+>#{label.name}</span></a>\.\)))
+      doc = reference_filter("Label (#{reference}).")
+      expect(doc.to_html).to match(%r(\(<a.+><span.+>#{label.name}</span></a>\)\.))
     end
 
     it 'ignores invalid label names' do
@@ -104,6 +104,55 @@ describe Banzai::Filter::LabelReferenceFilter, lib: true do
     end
   end
 
+  context 'String-based single-word references that begin with a digit' do
+    let(:label)     { create(:label, name: '2fa', project: project) }
+    let(:reference) { "#{Label.reference_prefix}#{label.name}" }
+
+    it 'links to a valid reference' do
+      doc = reference_filter("See #{reference}")
+
+      expect(doc.css('a').first.attr('href')).to eq urls.
+        namespace_project_issues_url(project.namespace, project, label_name: label.name)
+      expect(doc.text).to eq 'See 2fa'
+    end
+
+    it 'links with adjacent text' do
+      doc = reference_filter("Label (#{reference}).")
+      expect(doc.to_html).to match(%r(\(<a.+><span.+>#{label.name}</span></a>\)\.))
+    end
+
+    it 'ignores invalid label names' do
+      exp = act = "Label #{Label.reference_prefix}#{label.id}#{label.name.reverse}"
+
+      expect(reference_filter(act).to_html).to eq exp
+    end
+  end
+
+  context 'String-based single-word references with special characters' do
+    let(:label)     { create(:label, name: '?g.fm&', project: project) }
+    let(:reference) { "#{Label.reference_prefix}#{label.name}" }
+
+    it 'links to a valid reference' do
+      doc = reference_filter("See #{reference}")
+
+      expect(doc.css('a').first.attr('href')).to eq urls.
+        namespace_project_issues_url(project.namespace, project, label_name: label.name)
+      expect(doc.text).to eq 'See ?g.fm&'
+    end
+
+    it 'links with adjacent text' do
+      doc = reference_filter("Label (#{reference}).")
+      expect(doc.to_html).to match(%r(\(<a.+><span.+>\?g\.fm&amp;</span></a>\)\.))
+    end
+
+    it 'ignores invalid label names' do
+      act = "Label #{Label.reference_prefix}#{label.name.reverse}"
+      exp = "Label #{Label.reference_prefix}&amp;mf.g?"
+
+      expect(reference_filter(act).to_html).to eq exp
+    end
+  end
+
   context 'String-based multi-word references in quotes' do
     let(:label)     { create(:label, name: 'gfm references', project: project) }
     let(:reference) { label.to_reference(format: :name) }
@@ -128,6 +177,95 @@ describe Banzai::Filter::LabelReferenceFilter, lib: true do
     end
   end
 
+  context 'String-based multi-word references that begin with a digit' do
+    let(:label)     { create(:label, name: '2 factor authentication', project: project) }
+    let(:reference) { label.to_reference(format: :name) }
+
+    it 'links to a valid reference' do
+      doc = reference_filter("See #{reference}")
+
+      expect(doc.css('a').first.attr('href')).to eq urls.
+        namespace_project_issues_url(project.namespace, project, label_name: label.name)
+      expect(doc.text).to eq 'See 2 factor authentication'
+    end
+
+    it 'links with adjacent text' do
+      doc = reference_filter("Label (#{reference}.)")
+      expect(doc.to_html).to match(%r(\(<a.+><span.+>#{label.name}</span></a>\.\)))
+    end
+
+    it 'ignores invalid label names' do
+      exp = act = "Label #{Label.reference_prefix}#{label.id}#{label.name.reverse}"
+
+      expect(reference_filter(act).to_html).to eq exp
+    end
+  end
+
+  context 'String-based multi-word references with special characters in quotes' do
+    let(:label)     { create(:label, name: 'g.fm & references?', project: project) }
+    let(:reference) { label.to_reference(format: :name) }
+
+    it 'links to a valid reference' do
+      doc = reference_filter("See #{reference}")
+
+      expect(doc.css('a').first.attr('href')).to eq urls.
+        namespace_project_issues_url(project.namespace, project, label_name: label.name)
+      expect(doc.text).to eq 'See g.fm & references?'
+    end
+
+    it 'links with adjacent text' do
+      doc = reference_filter("Label (#{reference}.)")
+      expect(doc.to_html).to match(%r(\(<a.+><span.+>g\.fm &amp; references\?</span></a>\.\)))
+    end
+
+    it 'ignores invalid label names' do
+      act = %(Label #{Label.reference_prefix}"#{label.name.reverse}")
+      exp = %(Label #{Label.reference_prefix}"?secnerefer &amp; mf.g\")
+
+      expect(reference_filter(act).to_html).to eq exp
+    end
+  end
+
+  describe 'consecutive references' do
+    let(:bug) { create(:label, name: 'bug', project: project) }
+    let(:feature_proposal) { create(:label, name: 'feature proposal', project: project) }
+    let(:technical_debt) { create(:label, name: 'technical debt', project: project) }
+
+    let(:bug_reference) { "#{Label.reference_prefix}#{bug.name}" }
+    let(:feature_proposal_reference) { feature_proposal.to_reference(format: :name) }
+    let(:technical_debt_reference) { technical_debt.to_reference(format: :name) }
+
+    context 'separated with a comma' do
+      let(:references) { "#{bug_reference}, #{feature_proposal_reference}, #{technical_debt_reference}" }
+
+      it 'links to valid references' do
+        doc = reference_filter("See #{references}")
+
+        expect(doc.css('a').map { |a| a.attr('href') }).to match_array([
+          urls.namespace_project_issues_url(project.namespace, project, label_name: bug.name),
+          urls.namespace_project_issues_url(project.namespace, project, label_name: feature_proposal.name),
+          urls.namespace_project_issues_url(project.namespace, project, label_name: technical_debt.name)
+        ])
+        expect(doc.text).to eq 'See bug, feature proposal, technical debt'
+      end
+    end
+
+    context 'separated with a space' do
+      let(:references) { "#{bug_reference} #{feature_proposal_reference} #{technical_debt_reference}" }
+
+      it 'links to valid references' do
+        doc = reference_filter("See #{references}")
+
+        expect(doc.css('a').map { |a| a.attr('href') }).to match_array([
+          urls.namespace_project_issues_url(project.namespace, project, label_name: bug.name),
+          urls.namespace_project_issues_url(project.namespace, project, label_name: feature_proposal.name),
+          urls.namespace_project_issues_url(project.namespace, project, label_name: technical_debt.name)
+        ])
+        expect(doc.text).to eq 'See bug feature proposal technical debt'
+      end
+    end
+  end
+
   describe 'edge cases' do
     it 'gracefully handles non-references matching the pattern' do
       exp = act = '(format nil "~0f" 3.0) ; 3.0'
diff --git a/spec/lib/banzai/filter/syntax_highlight_filter_spec.rb b/spec/lib/banzai/filter/syntax_highlight_filter_spec.rb
index 407617f3307..b1370bca833 100644
--- a/spec/lib/banzai/filter/syntax_highlight_filter_spec.rb
+++ b/spec/lib/banzai/filter/syntax_highlight_filter_spec.rb
@@ -3,15 +3,35 @@ require 'spec_helper'
 describe Banzai::Filter::SyntaxHighlightFilter, lib: true do
   include FilterSpecHelper
 
-  it 'highlights valid code blocks' do
-    result = filter('<pre><code>def fun end</code>')
-    expect(result.to_html).to eq("<pre class=\"code highlight js-syntax-highlight plaintext\"><code>def fun end</code></pre>\n")
+  context "when no language is specified" do
+    it "highlights as plaintext" do
+      result = filter('<pre><code>def fun end</code></pre>')
+      expect(result.to_html).to eq('<pre class="code highlight js-syntax-highlight plaintext"><code>def fun end</code></pre>')
+    end
   end
 
-  it 'passes through invalid code blocks' do
-    allow_any_instance_of(described_class).to receive(:block_code).and_raise(StandardError)
+  context "when a valid language is specified" do
+    it "highlights as that language" do
+      result = filter('<pre><code class="ruby">def fun end</code></pre>')
+      expect(result.to_html).to eq('<pre class="code highlight js-syntax-highlight ruby"><code><span class="k">def</span> <span class="nf">fun</span> <span class="k">end</span></code></pre>')
+    end
+  end
+
+  context "when an invalid language is specified" do
+    it "highlights as plaintext" do
+      result = filter('<pre><code class="gnuplot">This is a test</code></pre>')
+      expect(result.to_html).to eq('<pre class="code highlight js-syntax-highlight plaintext"><code>This is a test</code></pre>')
+    end
+  end
+
+  context "when Rouge formatting fails" do
+    before do
+      allow_any_instance_of(Rouge::Formatter).to receive(:format).and_raise(StandardError)
+    end
 
-    result = filter('<pre><code>This is a test</code></pre>')
-    expect(result.to_html).to eq('<pre>This is a test</pre>')
+    it "highlights as plaintext" do
+      result = filter('<pre><code class="ruby">This is a test</code></pre>')
+      expect(result.to_html).to eq('<pre class="code highlight"><code>This is a test</code></pre>')
+    end
   end
 end
diff --git a/spec/lib/banzai/object_renderer_spec.rb b/spec/lib/banzai/object_renderer_spec.rb
index 44256b32bdc..bcdb95250ca 100644
--- a/spec/lib/banzai/object_renderer_spec.rb
+++ b/spec/lib/banzai/object_renderer_spec.rb
@@ -17,6 +17,7 @@ describe Banzai::ObjectRenderer do
         and_call_original
 
       expect(object).to receive(:note_html=).with('<p>hello</p>')
+      expect(object).to receive(:user_visible_reference_count=).with(0)
 
       renderer.render([object], :note)
     end
@@ -25,9 +26,10 @@ describe Banzai::ObjectRenderer do
   describe '#render_objects' do
     it 'renders an Array of objects' do
       object = double(:object, note: 'hello')
+
       renderer = described_class.new(project, user)
 
-      expect(renderer).to receive(:render_attribute).with(object, :note).
+      expect(renderer).to receive(:render_attributes).with([object], :note).
         and_call_original
 
       rendered = renderer.render_objects([object], :note)
@@ -38,7 +40,7 @@ describe Banzai::ObjectRenderer do
   end
 
   describe '#redact_documents' do
-    it 'redacts a set of documents and returns them as an Array of Strings' do
+    it 'redacts a set of documents and returns them as an Array of Hashes' do
       doc = Nokogiri::HTML.fragment('<p>hello</p>')
       renderer = described_class.new(project, user)
 
@@ -48,7 +50,9 @@ describe Banzai::ObjectRenderer do
 
       redacted = renderer.redact_documents([doc])
 
-      expect(redacted).to eq(['<p>hello</p>'])
+      expect(redacted.count).to eq(1)
+      expect(redacted.first[:visible_reference_count]).to eq(0)
+      expect(redacted.first[:document].to_html).to eq('<p>hello</p>')
     end
   end
 
@@ -85,14 +89,36 @@ describe Banzai::ObjectRenderer do
     end
   end
 
-  describe '#render_attribute' do
-    it 'renders the attribute of an object' do
-      object = double(:doc, note: 'hello')
+  describe '#render_attributes' do
+    it 'renders the attribute of a list of objects' do
+      objects = [double(:doc, note: 'hello'), double(:doc, note: 'bye')]
       renderer = described_class.new(project, user, pipeline: :note)
-      doc = renderer.render_attribute(object, :note)
 
-      expect(doc).to be_an_instance_of(Nokogiri::HTML::DocumentFragment)
-      expect(doc.to_html).to eq('<p>hello</p>')
+      expect(Banzai).to receive(:cache_collection_render).
+        with([
+          { text: 'hello', context: renderer.context_for(objects[0], :note) },
+          { text: 'bye', context: renderer.context_for(objects[1], :note) }
+        ]).
+        and_call_original
+
+      docs = renderer.render_attributes(objects, :note)
+
+      expect(docs[0]).to be_an_instance_of(Nokogiri::HTML::DocumentFragment)
+      expect(docs[0].to_html).to eq('<p>hello</p>')
+
+      expect(docs[1]).to be_an_instance_of(Nokogiri::HTML::DocumentFragment)
+      expect(docs[1].to_html).to eq('<p>bye</p>')
+    end
+
+    it 'returns when no objects to render' do
+      objects = []
+      renderer = described_class.new(project, user, pipeline: :note)
+
+      expect(Banzai).to receive(:cache_collection_render).
+        with([]).
+        and_call_original
+
+      expect(renderer.render_attributes(objects, :note)).to eq([])
     end
   end
 
diff --git a/spec/lib/banzai/redactor_spec.rb b/spec/lib/banzai/redactor_spec.rb
index 488f465bcda..254657a881d 100644
--- a/spec/lib/banzai/redactor_spec.rb
+++ b/spec/lib/banzai/redactor_spec.rb
@@ -15,11 +15,31 @@ describe Banzai::Redactor do
 
       expect(redactor).to receive(:nodes_visible_to_user).and_return([])
 
-      expect(redactor.redact([doc1, doc2])).to eq([doc1, doc2])
+      redacted_data = redactor.redact([doc1, doc2])
 
+      expect(redacted_data.map { |data| data[:document] }).to eq([doc1, doc2])
+      expect(redacted_data.map { |data| data[:visible_reference_count] }).to eq([0, 0])
       expect(doc1.to_html).to eq('foo')
       expect(doc2.to_html).to eq('bar')
     end
+
+    it 'does not redact an Array of documents' do
+      doc1_html = '<a class="gfm" data-reference-type="issue">foo</a>'
+      doc1 = Nokogiri::HTML.fragment(doc1_html)
+
+      doc2_html = '<a class="gfm" data-reference-type="issue">bar</a>'
+      doc2 = Nokogiri::HTML.fragment(doc2_html)
+
+      nodes = redactor.document_nodes([doc1, doc2]).map { |x| x[:nodes] }
+      expect(redactor).to receive(:nodes_visible_to_user).and_return(nodes.flatten)
+
+      redacted_data = redactor.redact([doc1, doc2])
+
+      expect(redacted_data.map { |data| data[:document] }).to eq([doc1, doc2])
+      expect(redacted_data.map { |data| data[:visible_reference_count] }).to eq([1, 1])
+      expect(doc1.to_html).to eq(doc1_html)
+      expect(doc2.to_html).to eq(doc2_html)
+    end
   end
 
   describe '#redact_nodes' do
@@ -31,7 +51,7 @@ describe Banzai::Redactor do
         with([node]).
         and_return(Set.new)
 
-      redactor.redact_nodes([node])
+      redactor.redact_document_nodes([{ document: doc, nodes: [node] }])
 
       expect(doc.to_html).to eq('foo')
     end
diff --git a/spec/lib/banzai/reference_parser/base_parser_spec.rb b/spec/lib/banzai/reference_parser/base_parser_spec.rb
index 543b4786d84..ac9c66e2663 100644
--- a/spec/lib/banzai/reference_parser/base_parser_spec.rb
+++ b/spec/lib/banzai/reference_parser/base_parser_spec.rb
@@ -234,4 +234,79 @@ describe Banzai::ReferenceParser::BaseParser, lib: true do
         to eq([project])
     end
   end
+
+  describe '#collection_objects_for_ids' do
+    context 'with RequestStore disabled' do
+      it 'queries the collection directly' do
+        collection = User.all
+
+        expect(collection).to receive(:where).twice.and_call_original
+
+        2.times do
+          expect(subject.collection_objects_for_ids(collection, [user.id])).
+            to eq([user])
+        end
+      end
+    end
+
+    context 'with RequestStore enabled' do
+      before do
+        cache = Hash.new { |hash, key| hash[key] = {} }
+
+        allow(RequestStore).to receive(:active?).and_return(true)
+        allow(subject).to receive(:collection_cache).and_return(cache)
+      end
+
+      it 'queries the collection on the first call' do
+        expect(subject.collection_objects_for_ids(User, [user.id])).
+          to eq([user])
+      end
+
+      it 'does not query previously queried objects' do
+        collection = User.all
+
+        expect(collection).to receive(:where).once.and_call_original
+
+        2.times do
+          expect(subject.collection_objects_for_ids(collection, [user.id])).
+            to eq([user])
+        end
+      end
+
+      it 'casts String based IDs to Fixnums before querying objects' do
+        2.times do
+          expect(subject.collection_objects_for_ids(User, [user.id.to_s])).
+            to eq([user])
+        end
+      end
+
+      it 'queries any additional objects after the first call' do
+        other_user = create(:user)
+
+        expect(subject.collection_objects_for_ids(User, [user.id])).
+          to eq([user])
+
+        expect(subject.collection_objects_for_ids(User, [user.id, other_user.id])).
+          to eq([user, other_user])
+      end
+
+      it 'caches objects on a per collection class basis' do
+        expect(subject.collection_objects_for_ids(User, [user.id])).
+          to eq([user])
+
+        expect(subject.collection_objects_for_ids(Project, [project.id])).
+          to eq([project])
+      end
+    end
+  end
+
+  describe '#collection_cache_key' do
+    it 'returns the cache key for a Class' do
+      expect(subject.collection_cache_key(Project)).to eq(Project)
+    end
+
+    it 'returns the cache key for an ActiveRecord::Relation' do
+      expect(subject.collection_cache_key(Project.all)).to eq(Project)
+    end
+  end
 end
diff --git a/spec/lib/ci/gitlab_ci_yaml_processor_spec.rb b/spec/lib/ci/gitlab_ci_yaml_processor_spec.rb
index c9602bcca22..d629bd252e2 100644
--- a/spec/lib/ci/gitlab_ci_yaml_processor_spec.rb
+++ b/spec/lib/ci/gitlab_ci_yaml_processor_spec.rb
@@ -31,7 +31,7 @@ module Ci
         })
       end
 
-      describe :only do
+      describe 'only' do
         it "does not return builds if only has another branch" do
           config = YAML.dump({
                                before_script: ["pwd"],
@@ -187,7 +187,7 @@ module Ci
         end
       end
 
-      describe :except do
+      describe 'except' do
         it "returns builds if except has another branch" do
           config = YAML.dump({
                                before_script: ["pwd"],
diff --git a/spec/lib/gitlab/build_data_builder_spec.rb b/spec/lib/gitlab/build_data_builder_spec.rb
index 38be9448794..23ae5cfacc4 100644
--- a/spec/lib/gitlab/build_data_builder_spec.rb
+++ b/spec/lib/gitlab/build_data_builder_spec.rb
@@ -3,7 +3,7 @@ require 'spec_helper'
 describe 'Gitlab::BuildDataBuilder' do
   let(:build) { create(:ci_build) }
 
-  describe :build do
+  describe '.build' do
     let(:data) do
       Gitlab::BuildDataBuilder.build(build)
     end
diff --git a/spec/lib/gitlab/database/migration_helpers_spec.rb b/spec/lib/gitlab/database/migration_helpers_spec.rb
index 9096ad101b0..4ec3f19e03f 100644
--- a/spec/lib/gitlab/database/migration_helpers_spec.rb
+++ b/spec/lib/gitlab/database/migration_helpers_spec.rb
@@ -13,6 +13,10 @@ describe Gitlab::Database::MigrationHelpers, lib: true do
     context 'outside a transaction' do
       before do
         expect(model).to receive(:transaction_open?).and_return(false)
+
+        unless Gitlab::Database.postgresql?
+          allow_any_instance_of(Gitlab::Database::MigrationHelpers).to receive(:disable_statement_timeout)
+        end
       end
 
       context 'using PostgreSQL' do
diff --git a/spec/lib/gitlab/diff/file_spec.rb b/spec/lib/gitlab/diff/file_spec.rb
index a0cbef6e6a4..0460dcf4658 100644
--- a/spec/lib/gitlab/diff/file_spec.rb
+++ b/spec/lib/gitlab/diff/file_spec.rb
@@ -6,16 +6,16 @@ describe Gitlab::Diff::File, lib: true do
   let(:project) { create(:project) }
   let(:commit) { project.commit(sample_commit.id) }
   let(:diff) { commit.diffs.first }
-  let(:diff_file) { Gitlab::Diff::File.new(diff, [commit.parent, commit]) }
+  let(:diff_file) { Gitlab::Diff::File.new(diff, diff_refs: commit.diff_refs, repository: project.repository) }
 
-  describe :diff_lines do
+  describe '#diff_lines' do
     let(:diff_lines) { diff_file.diff_lines }
 
     it { expect(diff_lines.size).to eq(30) }
     it { expect(diff_lines.first).to be_kind_of(Gitlab::Diff::Line) }
   end
 
-  describe :mode_changed? do
+  describe '#mode_changed?' do
     it { expect(diff_file.mode_changed?).to be_falsey }
   end
 
diff --git a/spec/lib/gitlab/diff/highlight_spec.rb b/spec/lib/gitlab/diff/highlight_spec.rb
index d19bf4ac84b..88e4115c453 100644
--- a/spec/lib/gitlab/diff/highlight_spec.rb
+++ b/spec/lib/gitlab/diff/highlight_spec.rb
@@ -6,11 +6,11 @@ describe Gitlab::Diff::Highlight, lib: true do
   let(:project) { create(:project) }
   let(:commit) { project.commit(sample_commit.id) }
   let(:diff) { commit.diffs.first }
-  let(:diff_file) { Gitlab::Diff::File.new(diff, [commit.parent, commit]) }
+  let(:diff_file) { Gitlab::Diff::File.new(diff, diff_refs: commit.diff_refs, repository: project.repository) }
 
   describe '#highlight' do
     context "with a diff file" do
-      let(:subject) { Gitlab::Diff::Highlight.new(diff_file).highlight }
+      let(:subject) { Gitlab::Diff::Highlight.new(diff_file, repository: project.repository).highlight }
 
       it 'should return Gitlab::Diff::Line elements' do
         expect(subject.first).to be_an_instance_of(Gitlab::Diff::Line)
@@ -28,20 +28,20 @@ describe Gitlab::Diff::Highlight, lib: true do
       end
 
       it 'highlights and marks removed lines' do
-        code = %Q{-<span id="LC9" class="line">      <span class="k">raise</span> <span class="s2">&quot;System commands must be given as an array of strings&quot;</span></span>\n}
+        code = %Q{-<span id="LC9" class="line">      <span class="k">raise</span> <span class="s2">"System commands must be given as an array of strings"</span></span>\n}
 
         expect(subject[4].text).to eq(code)
       end
 
       it 'highlights and marks added lines' do
-        code = %Q{+<span id="LC9" class="line">      <span class="k">raise</span> <span class="no"><span class='idiff left'>RuntimeError</span></span><span class="p"><span class='idiff'>,</span></span><span class='idiff right'> </span><span class="s2">&quot;System commands must be given as an array of strings&quot;</span></span>\n}
+        code = %Q{+<span id="LC9" class="line">      <span class="k">raise</span> <span class="no"><span class='idiff left'>RuntimeError</span></span><span class="p"><span class='idiff'>,</span></span><span class='idiff right'> </span><span class="s2">"System commands must be given as an array of strings"</span></span>\n}
 
         expect(subject[5].text).to eq(code)
       end
     end
 
     context "with diff lines" do
-      let(:subject) { Gitlab::Diff::Highlight.new(diff_file.diff_lines).highlight }
+      let(:subject) { Gitlab::Diff::Highlight.new(diff_file.diff_lines, repository: project.repository).highlight }
 
       it 'should return Gitlab::Diff::Line elements' do
         expect(subject.first).to be_an_instance_of(Gitlab::Diff::Line)
diff --git a/spec/lib/gitlab/diff/inline_diff_spec.rb b/spec/lib/gitlab/diff/inline_diff_spec.rb
index 95a993d26cf..8ca3f73509e 100644
--- a/spec/lib/gitlab/diff/inline_diff_spec.rb
+++ b/spec/lib/gitlab/diff/inline_diff_spec.rb
@@ -3,14 +3,19 @@ require 'spec_helper'
 describe Gitlab::Diff::InlineDiff, lib: true do
   describe '.for_lines' do
     let(:diff) do
-      <<eos
- class Test
--  def initialize(test = true)
-+  def initialize(test = false)
-     @test = test
-   end
- end
-eos
+      <<-EOF.strip_heredoc
+         class Test
+        -  def initialize(test = true)
+        +  def initialize(test = false)
+             @test = test
+        -    if true
+        -      @foo = "bar"
+        +    unless false
+        +      @foo = "baz"
+             end
+           end
+         end
+      EOF
     end
 
     let(:subject) { described_class.for_lines(diff.lines) }
@@ -20,8 +25,11 @@ eos
       expect(subject[1]).to eq([25..27])
       expect(subject[2]).to eq([25..28])
       expect(subject[3]).to be_nil
-      expect(subject[4]).to be_nil
-      expect(subject[5]).to be_nil
+      expect(subject[4]).to eq([5..10])
+      expect(subject[5]).to eq([17..17])
+      expect(subject[6]).to eq([5..15])
+      expect(subject[7]).to eq([17..17])
+      expect(subject[8]).to be_nil
     end
   end
 
diff --git a/spec/lib/gitlab/diff/line_mapper_spec.rb b/spec/lib/gitlab/diff/line_mapper_spec.rb
new file mode 100644
index 00000000000..4e50e03bb7e
--- /dev/null
+++ b/spec/lib/gitlab/diff/line_mapper_spec.rb
@@ -0,0 +1,137 @@
+require 'spec_helper'
+
+describe Gitlab::Diff::LineMapper, lib: true do
+  include RepoHelpers
+
+  let(:project) { create(:project) }
+  let(:repository) { project.repository }
+  let(:commit) { project.commit(sample_commit.id) }
+  let(:diffs) { commit.diffs }
+  let(:diff) { diffs.first }
+  let(:diff_file) { Gitlab::Diff::File.new(diff, diff_refs: commit.diff_refs, repository: repository) }
+  subject { described_class.new(diff_file) }
+
+  describe '#old_to_new' do
+    context "with a diff file" do
+      let(:mapping) do
+        {
+          1 => 1,
+          2 => 2,
+          3 => 3,
+          4 => 4,
+          5 => 5,
+          6 => 6,
+          7 => 7,
+          8 => 8,
+          9 => nil,
+          # nil => 9,
+          10 => 10,
+          11 => 11,
+          12 => 12,
+          13 => nil,
+          14 => nil,
+          # nil => 15,
+          # nil => 16,
+          # nil => 17,
+          # nil => 18,
+          # nil => 19,
+          # nil => 20,
+          15 => 21,
+          16 => 22,
+          17 => 23,
+          18 => 24,
+          19 => 25,
+          20 => 26,
+          21 => 27,
+          # nil => 28,
+          22 => 29,
+          23 => 30,
+          24 => 31,
+          25 => 32,
+          26 => 33,
+          27 => 34,
+          28 => 35,
+          29 => 36,
+          30 => 37
+        }
+      end
+
+      it 'returns the new line number for the old line number' do
+        mapping.each do |old_line, new_line|
+          expect(subject.old_to_new(old_line)).to eq(new_line)
+        end
+      end
+    end
+
+    context "without a diff file" do
+      let(:diff_file) { nil }
+
+      it "returns the same line number" do
+        expect(subject.old_to_new(100)).to eq(100)
+      end
+    end
+  end
+
+  describe '#new_to_old' do
+    context "with a diff file" do
+      let(:mapping) do
+        {
+          1 => 1,
+          2 => 2,
+          3 => 3,
+          4 => 4,
+          5 => 5,
+          6 => 6,
+          7 => 7,
+          8 => 8,
+          # nil => 9,
+          9 => nil,
+          10 => 10,
+          11 => 11,
+          12 => 12,
+          # nil => 13,
+          # nil => 14,
+          13 => nil,
+          14 => nil,
+          15 => nil,
+          16 => nil,
+          17 => nil,
+          18 => nil,
+          19 => nil,
+          20 => nil,
+          21 => 15,
+          22 => 16,
+          23 => 17,
+          24 => 18,
+          25 => 19,
+          26 => 20,
+          27 => 21,
+          28 => nil,
+          29 => 22,
+          30 => 23,
+          31 => 24,
+          32 => 25,
+          33 => 26,
+          34 => 27,
+          35 => 28,
+          36 => 29,
+          37 => 30
+        }
+      end
+
+      it 'returns the old line number for the new line number' do
+        mapping.each do |new_line, old_line|
+          expect(subject.new_to_old(new_line)).to eq(old_line)
+        end
+      end
+    end
+
+    context "without a diff file" do
+      let(:diff_file) { nil }
+
+      it "returns the same line number" do
+        expect(subject.new_to_old(100)).to eq(100)
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/diff/parallel_diff_spec.rb b/spec/lib/gitlab/diff/parallel_diff_spec.rb
index 1c5bbc47120..5f76b70c6f5 100644
--- a/spec/lib/gitlab/diff/parallel_diff_spec.rb
+++ b/spec/lib/gitlab/diff/parallel_diff_spec.rb
@@ -8,8 +8,7 @@ describe Gitlab::Diff::ParallelDiff, lib: true do
   let(:commit) { project.commit(sample_commit.id) }
   let(:diffs) { commit.diffs }
   let(:diff) { diffs.first }
-  let(:diff_refs) { [commit.parent, commit] }
-  let(:diff_file) { Gitlab::Diff::File.new(diff, diff_refs) }
+  let(:diff_file) { Gitlab::Diff::File.new(diff, diff_refs: commit.diff_refs, repository: repository) }
   subject { described_class.new(diff_file) }
 
   let(:parallel_diff_result_array) { YAML.load_file("#{Rails.root}/spec/fixtures/parallel_diff_result.yml") }
diff --git a/spec/lib/gitlab/diff/parser_spec.rb b/spec/lib/gitlab/diff/parser_spec.rb
index cdff063a9ed..c3359627652 100644
--- a/spec/lib/gitlab/diff/parser_spec.rb
+++ b/spec/lib/gitlab/diff/parser_spec.rb
@@ -8,7 +8,7 @@ describe Gitlab::Diff::Parser, lib: true do
   let(:diff) { commit.diffs.first }
   let(:parser) { Gitlab::Diff::Parser.new }
 
-  describe :parse do
+  describe '#parse' do
     let(:diff) do
       <<eos
 --- a/files/ruby/popen.rb
diff --git a/spec/lib/gitlab/diff/position_spec.rb b/spec/lib/gitlab/diff/position_spec.rb
new file mode 100644
index 00000000000..cf28628cb96
--- /dev/null
+++ b/spec/lib/gitlab/diff/position_spec.rb
@@ -0,0 +1,341 @@
+require 'spec_helper'
+
+describe Gitlab::Diff::Position, lib: true do
+  include RepoHelpers
+
+  let(:project) { create(:project) }
+
+  describe "position for an added file" do
+    let(:commit) { project.commit("2ea1f3dec713d940208fb5ce4a38765ecb5d3f73") }
+
+    subject do
+      described_class.new(
+        old_path: "files/images/wm.svg",
+        new_path: "files/images/wm.svg",
+        old_line: nil,
+        new_line: 5,
+        diff_refs: commit.diff_refs
+      )
+    end
+
+    describe "#diff_file" do
+      it "returns the correct diff file" do
+        diff_file = subject.diff_file(project.repository)
+
+        expect(diff_file.new_file).to be true
+        expect(diff_file.new_path).to eq(subject.new_path)
+        expect(diff_file.diff_refs).to eq(subject.diff_refs)
+      end
+    end
+
+    describe "#diff_line" do
+      it "returns the correct diff line" do
+        diff_line = subject.diff_line(project.repository)
+
+        expect(diff_line.added?).to be true
+        expect(diff_line.new_line).to eq(subject.new_line)
+        expect(diff_line.text).to eq("+    <desc>Created with Sketch.</desc>")
+      end
+    end
+
+    describe "#line_code" do
+      it "returns the correct line code" do
+        line_code = Gitlab::Diff::LineCode.generate(subject.file_path, subject.new_line, 0)
+
+        expect(subject.line_code(project.repository)).to eq(line_code)
+      end
+    end
+  end
+
+  describe "position for a changed file" do
+    let(:commit) { project.commit("570e7b2abdd848b95f2f578043fc23bd6f6fd24d") }
+
+    describe "position for an added line" do
+      subject do
+        described_class.new(
+          old_path: "files/ruby/popen.rb",
+          new_path: "files/ruby/popen.rb",
+          old_line: nil,
+          new_line: 14,
+          diff_refs: commit.diff_refs
+        )
+      end
+
+      describe "#diff_file" do
+        it "returns the correct diff file" do
+          diff_file = subject.diff_file(project.repository)
+
+          expect(diff_file.old_path).to eq(subject.old_path)
+          expect(diff_file.new_path).to eq(subject.new_path)
+          expect(diff_file.diff_refs).to eq(subject.diff_refs)
+        end
+      end
+
+      describe "#diff_line" do
+        it "returns the correct diff line" do
+          diff_line = subject.diff_line(project.repository)
+
+          expect(diff_line.added?).to be true
+          expect(diff_line.new_line).to eq(subject.new_line)
+          expect(diff_line.text).to eq("+    vars = {")
+        end
+      end
+
+      describe "#line_code" do
+        it "returns the correct line code" do
+          line_code = Gitlab::Diff::LineCode.generate(subject.file_path, subject.new_line, 15)
+
+          expect(subject.line_code(project.repository)).to eq(line_code)
+        end
+      end
+    end
+
+    describe "position for an unchanged line" do
+      subject do
+        described_class.new(
+          old_path: "files/ruby/popen.rb",
+          new_path: "files/ruby/popen.rb",
+          old_line: 16,
+          new_line: 22,
+          diff_refs: commit.diff_refs
+        )
+      end
+
+      describe "#diff_file" do
+        it "returns the correct diff file" do
+          diff_file = subject.diff_file(project.repository)
+
+          expect(diff_file.old_path).to eq(subject.old_path)
+          expect(diff_file.new_path).to eq(subject.new_path)
+          expect(diff_file.diff_refs).to eq(subject.diff_refs)
+        end
+      end
+
+      describe "#diff_line" do
+        it "returns the correct diff line" do
+          diff_line = subject.diff_line(project.repository)
+
+          expect(diff_line.unchanged?).to be true
+          expect(diff_line.old_line).to eq(subject.old_line)
+          expect(diff_line.new_line).to eq(subject.new_line)
+          expect(diff_line.text).to eq("     unless File.directory?(path)")
+        end
+      end
+
+      describe "#line_code" do
+        it "returns the correct line code" do
+          line_code = Gitlab::Diff::LineCode.generate(subject.file_path, subject.new_line, subject.old_line)
+
+          expect(subject.line_code(project.repository)).to eq(line_code)
+        end
+      end
+    end
+
+    describe "position for a removed line" do
+      subject do
+        described_class.new(
+          old_path: "files/ruby/popen.rb",
+          new_path: "files/ruby/popen.rb",
+          old_line: 14,
+          new_line: nil,
+          diff_refs: commit.diff_refs
+        )
+      end
+
+      describe "#diff_file" do
+        it "returns the correct diff file" do
+          diff_file = subject.diff_file(project.repository)
+
+          expect(diff_file.old_path).to eq(subject.old_path)
+          expect(diff_file.new_path).to eq(subject.new_path)
+          expect(diff_file.diff_refs).to eq(subject.diff_refs)
+        end
+      end
+
+      describe "#diff_line" do
+        it "returns the correct diff line" do
+          diff_line = subject.diff_line(project.repository)
+
+          expect(diff_line.removed?).to be true
+          expect(diff_line.old_line).to eq(subject.old_line)
+          expect(diff_line.text).to eq("-    options = { chdir: path }")
+        end
+      end
+
+      describe "#line_code" do
+        it "returns the correct line code" do
+          line_code = Gitlab::Diff::LineCode.generate(subject.file_path, 13, subject.old_line)
+
+          expect(subject.line_code(project.repository)).to eq(line_code)
+        end
+      end
+    end
+  end
+
+  describe "position for a renamed file" do
+    let(:commit) { project.commit("6907208d755b60ebeacb2e9dfea74c92c3449a1f") }
+
+    describe "position for an added line" do
+      subject do
+        described_class.new(
+          old_path: "files/js/commit.js.coffee",
+          new_path: "files/js/commit.coffee",
+          old_line: nil,
+          new_line: 4,
+          diff_refs: commit.diff_refs
+        )
+      end
+
+      describe "#diff_file" do
+        it "returns the correct diff file" do
+          diff_file = subject.diff_file(project.repository)
+
+          expect(diff_file.old_path).to eq(subject.old_path)
+          expect(diff_file.new_path).to eq(subject.new_path)
+          expect(diff_file.diff_refs).to eq(subject.diff_refs)
+        end
+      end
+
+      describe "#diff_line" do
+        it "returns the correct diff line" do
+          diff_line = subject.diff_line(project.repository)
+
+          expect(diff_line.added?).to be true
+          expect(diff_line.new_line).to eq(subject.new_line)
+          expect(diff_line.text).to eq("+      new CommitFile(@)")
+        end
+      end
+
+      describe "#line_code" do
+        it "returns the correct line code" do
+          line_code = Gitlab::Diff::LineCode.generate(subject.file_path, subject.new_line, 5)
+
+          expect(subject.line_code(project.repository)).to eq(line_code)
+        end
+      end
+    end
+
+    describe "position for an unchanged line" do
+      subject do
+        described_class.new(
+          old_path: "files/js/commit.js.coffee",
+          new_path: "files/js/commit.coffee",
+          old_line: 3,
+          new_line: 3,
+          diff_refs: commit.diff_refs
+        )
+      end
+
+      describe "#diff_file" do
+        it "returns the correct diff file" do
+          diff_file = subject.diff_file(project.repository)
+
+          expect(diff_file.old_path).to eq(subject.old_path)
+          expect(diff_file.new_path).to eq(subject.new_path)
+          expect(diff_file.diff_refs).to eq(subject.diff_refs)
+        end
+      end
+
+      describe "#diff_line" do
+        it "returns the correct diff line" do
+          diff_line = subject.diff_line(project.repository)
+
+          expect(diff_line.unchanged?).to be true
+          expect(diff_line.old_line).to eq(subject.old_line)
+          expect(diff_line.new_line).to eq(subject.new_line)
+          expect(diff_line.text).to eq("     $('.files .diff-file').each ->")
+        end
+      end
+
+      describe "#line_code" do
+        it "returns the correct line code" do
+          line_code = Gitlab::Diff::LineCode.generate(subject.file_path, subject.new_line, subject.old_line)
+
+          expect(subject.line_code(project.repository)).to eq(line_code)
+        end
+      end
+    end
+
+    describe "position for a removed line" do
+      subject do
+        described_class.new(
+          old_path: "files/js/commit.js.coffee",
+          new_path: "files/js/commit.coffee",
+          old_line: 4,
+          new_line: nil,
+          diff_refs: commit.diff_refs
+        )
+      end
+
+      describe "#diff_file" do
+        it "returns the correct diff file" do
+          diff_file = subject.diff_file(project.repository)
+
+          expect(diff_file.old_path).to eq(subject.old_path)
+          expect(diff_file.new_path).to eq(subject.new_path)
+          expect(diff_file.diff_refs).to eq(subject.diff_refs)
+        end
+      end
+
+      describe "#diff_line" do
+        it "returns the correct diff line" do
+          diff_line = subject.diff_line(project.repository)
+
+          expect(diff_line.removed?).to be true
+          expect(diff_line.old_line).to eq(subject.old_line)
+          expect(diff_line.text).to eq("-      new CommitFile(this)")
+        end
+      end
+
+      describe "#line_code" do
+        it "returns the correct line code" do
+          line_code = Gitlab::Diff::LineCode.generate(subject.file_path, 4, subject.old_line)
+
+          expect(subject.line_code(project.repository)).to eq(line_code)
+        end
+      end
+    end
+  end
+
+  describe "position for a deleted file" do
+    let(:commit) { project.commit("8634272bfad4cf321067c3e94d64d5a253f8321d") }
+
+    subject do
+      described_class.new(
+        old_path: "LICENSE",
+        new_path: "LICENSE",
+        old_line: 3,
+        new_line: nil,
+        diff_refs: commit.diff_refs
+      )
+    end
+
+    describe "#diff_file" do
+      it "returns the correct diff file" do
+        diff_file = subject.diff_file(project.repository)
+
+        expect(diff_file.deleted_file).to be true
+        expect(diff_file.old_path).to eq(subject.old_path)
+        expect(diff_file.diff_refs).to eq(subject.diff_refs)
+      end
+    end
+
+    describe "#diff_line" do
+      it "returns the correct diff line" do
+        diff_line = subject.diff_line(project.repository)
+
+        expect(diff_line.removed?).to be true
+        expect(diff_line.old_line).to eq(subject.old_line)
+        expect(diff_line.text).to eq("-Copyright (c) 2014 gitlabhq")
+      end
+    end
+
+    describe "#line_code" do
+      it "returns the correct line code" do
+        line_code = Gitlab::Diff::LineCode.generate(subject.file_path, 0, subject.old_line)
+
+        expect(subject.line_code(project.repository)).to eq(line_code)
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/diff/position_tracer_spec.rb b/spec/lib/gitlab/diff/position_tracer_spec.rb
new file mode 100644
index 00000000000..08312e60f4a
--- /dev/null
+++ b/spec/lib/gitlab/diff/position_tracer_spec.rb
@@ -0,0 +1,1758 @@
+require 'spec_helper'
+
+describe Gitlab::Diff::PositionTracer, lib: true do
+  # Douwe's diary                                    New York City, 2016-06-28
+  # --------------------------------------------------------------------------
+  #
+  # Dear diary,
+  #
+  # Ideally, we would have a test for every single diff scenario that can
+  # occur and that the PositionTracer should correctly trace a position
+  # through, across the following variables:
+  #
+  # - Old diff file type: created, changed, renamed, deleted, unchanged (5)
+  # - Old diff line type: added, removed, unchanged (3)
+  # - New diff file type: created, changed, renamed, deleted, unchanged (5)
+  # - New diff line type: added, removed, unchanged (3)
+  # - Old-to-new diff line change: kept, moved, undone (3)
+  #
+  # This adds up to 5 * 3 * 5 * 3 * 3 = 675 different potential scenarios,
+  # and 675 different tests to cover them all. In reality, it would be fewer,
+  # since one cannot have a removed line in a created file diff, for example,
+  # but for the sake of this diary entry, let's be pessimistic.
+  #
+  # Writing these tests is a manual and time consuming process, as every test
+  # requires the manual construction or finding of a combination of diffs that
+  # create the exact diff scenario we are looking for, and can take between
+  # 1 and 10 minutes, depending on the farfetchedness of the scenario and
+  # complexity of creating it.
+  #
+  # This means that writing tests to cover all of these scenarios would end up
+  # taking between 11 and 112 hours in total, which I do not believe is the
+  # best use of my time.
+  #
+  # A better course of action would be to think of scenarios that are likely
+  # to occur, but also potentially tricky to trace correctly, and only cover
+  # those, with a few more obvious scenarios thrown in to cover our bases.
+  #
+  # Unfortunately, I only came to the above realization once I was about
+  # 1/5th of the way through the process of writing ALL THE SPECS, having
+  # already wasted about 3 hours trying to be thorough.
+  #
+  # I did find 2 bugs while writing those though, so that's good.
+  #
+  # In any case, all of this means that the tests below will be extremely
+  # (excessively, unjustifiably) thorough for scenarios where "the file was
+  # created in the old diff" and then drop off to comparitively lackluster
+  # testing of other scenarios.
+  #
+  # I did still try to cover most of the obvious and potentially tricky
+  # scenarios, though.
+
+  include RepoHelpers
+
+  let(:project) { create(:project) }
+  let(:current_user) { project.owner }
+  let(:repository) { project.repository }
+  let(:file_name) { "test-file" }
+  let(:new_file_name) { "#{file_name}-new" }
+  let(:second_file_name) { "#{file_name}-2" }
+  let(:branch_name) { "position-tracer-test" }
+
+  let(:old_diff_refs) { raise NotImplementedError }
+  let(:new_diff_refs) { raise NotImplementedError }
+  let(:old_position) { raise NotImplementedError }
+
+  let(:position_tracer) { described_class.new(repository: project.repository, old_diff_refs: old_diff_refs, new_diff_refs: new_diff_refs) }
+  subject { position_tracer.trace(old_position) }
+
+  def diff_refs(base_commit, head_commit)
+    Gitlab::Diff::DiffRefs.new(base_sha: base_commit.id, head_sha: head_commit.id)
+  end
+
+  def position(attrs = {})
+    attrs.reverse_merge!(
+      diff_refs: old_diff_refs
+    )
+    Gitlab::Diff::Position.new(attrs)
+  end
+
+  def expect_new_position(attrs, new_position = subject)
+    if attrs.nil?
+      expect(new_position).to be_nil
+    else
+      expect(new_position).not_to be_nil
+
+      expect(new_position.diff_refs).to eq(new_diff_refs)
+
+      attrs.each do |attr, value|
+        expect(new_position.send(attr)).to eq(value)
+      end
+    end
+  end
+
+  def create_branch(new_name, branch_name)
+    CreateBranchService.new(project, current_user).execute(new_name, branch_name)
+  end
+
+  def create_file(branch_name, file_name, content)
+    Files::CreateService.new(
+      project,
+      current_user,
+      source_branch: branch_name,
+      target_branch: branch_name,
+      commit_message: "Create file",
+      file_path: file_name,
+      file_content: content
+    ).execute
+    project.commit(branch_name)
+  end
+
+  def update_file(branch_name, file_name, content)
+    Files::UpdateService.new(
+      project,
+      current_user,
+      source_branch: branch_name,
+      target_branch: branch_name,
+      commit_message: "Update file",
+      file_path: file_name,
+      file_content: content
+    ).execute
+    project.commit(branch_name)
+  end
+
+  def delete_file(branch_name, file_name)
+    Files::DeleteService.new(
+      project,
+      current_user,
+      source_branch: branch_name,
+      target_branch: branch_name,
+      commit_message: "Delete file",
+      file_path: file_name
+    ).execute
+    project.commit(branch_name)
+  end
+
+  let(:initial_commit) do
+    create_branch(branch_name, "master")[:branch].name
+    project.commit(branch_name)
+  end
+
+  describe "#trace" do
+    describe "diff scenarios" do
+      let(:create_file_commit) do
+        initial_commit
+
+        create_file(
+          branch_name,
+          file_name,
+          <<-CONTENT.strip_heredoc
+            A
+            B
+            C
+          CONTENT
+        )
+      end
+
+      let(:create_second_file_commit) do
+        create_file_commit
+
+        create_file(
+          branch_name,
+          second_file_name,
+          <<-CONTENT.strip_heredoc
+            D
+            E
+          CONTENT
+        )
+      end
+
+      let(:update_line_commit) do
+        create_second_file_commit
+
+        update_file(
+          branch_name,
+          file_name,
+          <<-CONTENT.strip_heredoc
+            A
+            BB
+            C
+          CONTENT
+        )
+      end
+
+      let(:update_second_file_line_commit) do
+        update_line_commit
+
+        update_file(
+          branch_name,
+          second_file_name,
+          <<-CONTENT.strip_heredoc
+            D
+            EE
+          CONTENT
+        )
+      end
+
+      let(:move_line_commit) do
+        update_second_file_line_commit
+
+        update_file(
+          branch_name,
+          file_name,
+          <<-CONTENT.strip_heredoc
+            BB
+            A
+            C
+          CONTENT
+        )
+      end
+
+      let(:add_second_file_line_commit) do
+        move_line_commit
+
+        update_file(
+          branch_name,
+          second_file_name,
+          <<-CONTENT.strip_heredoc
+            D
+            EE
+            F
+          CONTENT
+        )
+      end
+
+      let(:move_second_file_line_commit) do
+        add_second_file_line_commit
+
+        update_file(
+          branch_name,
+          second_file_name,
+          <<-CONTENT.strip_heredoc
+            D
+            F
+            EE
+          CONTENT
+        )
+      end
+
+      let(:delete_line_commit) do
+        move_second_file_line_commit
+
+        update_file(
+          branch_name,
+          file_name,
+          <<-CONTENT.strip_heredoc
+            BB
+            A
+          CONTENT
+        )
+      end
+
+      let(:delete_second_file_line_commit) do
+        delete_line_commit
+
+        update_file(
+          branch_name,
+          second_file_name,
+          <<-CONTENT.strip_heredoc
+            D
+            F
+          CONTENT
+        )
+      end
+
+      let(:delete_file_commit) do
+        delete_second_file_line_commit
+
+        delete_file(branch_name, file_name)
+      end
+
+      let(:rename_file_commit) do
+        delete_file_commit
+
+        create_file(
+          branch_name,
+          new_file_name,
+          <<-CONTENT.strip_heredoc
+            BB
+            A
+          CONTENT
+        )
+      end
+
+      let(:update_line_again_commit) do
+        rename_file_commit
+
+        update_file(
+          branch_name,
+          new_file_name,
+          <<-CONTENT.strip_heredoc
+            BB
+            AA
+          CONTENT
+        )
+      end
+
+      let(:move_line_again_commit) do
+        update_line_again_commit
+
+        update_file(
+          branch_name,
+          new_file_name,
+          <<-CONTENT.strip_heredoc
+            AA
+            BB
+          CONTENT
+        )
+      end
+
+      let(:delete_line_again_commit) do
+        move_line_again_commit
+
+        update_file(
+          branch_name,
+          new_file_name,
+          <<-CONTENT.strip_heredoc
+            AA
+          CONTENT
+        )
+      end
+
+      context "when the file was created in the old diff" do
+        context "when the file is created in the new diff" do
+          context "when the position pointed at an added line in the old diff" do
+            context "when the file's content was unchanged between the old and the new diff" do
+              let(:old_diff_refs) { diff_refs(initial_commit, create_file_commit) }
+              let(:new_diff_refs) { diff_refs(initial_commit, create_second_file_commit) }
+              let(:old_position) { position(new_path: file_name, new_line: 2) }
+
+              # old diff:
+              #   1 + A
+              #   2 + B
+              #   3 + C
+              #
+              # new diff:
+              #   1 + A
+              #   2 + B
+              #   3 + C
+
+              it "returns the new position" do
+                expect_new_position(
+                  new_path: old_position.new_path,
+                  new_line: old_position.new_line
+                )
+              end
+            end
+
+            context "when the file's content was changed between the old and the new diff" do
+              context "when that line was unchanged between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, create_file_commit) }
+                let(:new_diff_refs) { diff_refs(initial_commit, update_line_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 1) }
+
+                # old diff:
+                #   1 + A
+                #   2 + B
+                #   3 + C
+                #
+                # new diff:
+                #   1 + A
+                #   2 + BB
+                #   3 + C
+
+                it "returns the new position" do
+                  expect_new_position(
+                    new_path: old_position.new_path,
+                    new_line: old_position.new_line
+                  )
+                end
+              end
+
+              context "when that line was moved between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, update_line_commit) }
+                let(:new_diff_refs) { diff_refs(initial_commit, move_line_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 2) }
+
+                # old diff:
+                #   1 + A
+                #   2 + BB
+                #   3 + C
+                #
+                # new diff:
+                #   1 + BB
+                #   2 + A
+                #   3 + C
+
+                it "returns the new position" do
+                  expect_new_position(
+                    new_path: old_position.new_path,
+                    new_line: 1
+                  )
+                end
+              end
+
+              context "when that line was changed between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, create_file_commit) }
+                let(:new_diff_refs) { diff_refs(initial_commit, update_line_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 2) }
+
+                # old diff:
+                #   1 + A
+                #   2 + B
+                #   3 + C
+                #
+                # new diff:
+                #   1 + A
+                #   2 + BB
+                #   3 + C
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+
+              context "when that line was deleted between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, update_line_commit) }
+                let(:new_diff_refs) { diff_refs(initial_commit, delete_line_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 3) }
+
+                # old diff:
+                #   1 + A
+                #   2 + BB
+                #   3 + C
+                #
+                # new diff:
+                #   1 + A
+                #   2 + BB
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+            end
+          end
+        end
+
+        context "when the file is changed in the new diff" do
+          context "when the position pointed at an added line in the old diff" do
+            context "when the file's content was unchanged between the old and the new diff" do
+              let(:old_diff_refs) { diff_refs(initial_commit, update_line_commit) }
+              let(:new_diff_refs) { diff_refs(create_file_commit, update_line_commit) }
+              let(:old_position) { position(new_path: file_name, new_line: 1) }
+
+              # old diff:
+              #   1 + A
+              #   2 + BB
+              #   3 + C
+              #
+              # new diff:
+              # 1 1   A
+              # 2   - B
+              #   2 + BB
+              # 3 3   C
+
+              it "returns the new position" do
+                expect_new_position(
+                  new_path: old_position.new_path,
+                  new_line: old_position.new_line
+                )
+              end
+            end
+
+            context "when the file's content was changed between the old and the new diff" do
+              context "when that line was unchanged between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, update_line_commit) }
+                let(:new_diff_refs) { diff_refs(update_line_commit, move_line_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 3) }
+
+                # old diff:
+                #   1 + A
+                #   2 + BB
+                #   3 + C
+                #
+                # new diff:
+                # 1   - A
+                # 2 1   BB
+                #   2 + A
+                # 3 3   C
+
+                it "returns the new position" do
+                  expect_new_position(
+                    new_path: old_position.new_path,
+                    new_line: old_position.new_line
+                  )
+                end
+              end
+
+              context "when that line was moved between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, update_line_commit) }
+                let(:new_diff_refs) { diff_refs(update_line_commit, move_line_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 2) }
+
+                # old diff:
+                #   1 + A
+                #   2 + BB
+                #   3 + C
+                #
+                # new diff:
+                # 1   - A
+                # 2 1   BB
+                #   2 + A
+                # 3 3   C
+
+                it "returns the new position" do
+                  expect_new_position(
+                    new_path: old_position.new_path,
+                    new_line: 1
+                  )
+                end
+              end
+
+              context "when that line was changed between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, create_file_commit) }
+                let(:new_diff_refs) { diff_refs(create_file_commit, update_line_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 2) }
+
+                # old diff:
+                #   1 + A
+                #   2 + B
+                #   3 + C
+                #
+                # new diff:
+                # 1 1   A
+                # 2   - B
+                #   2 + BB
+                # 3 3   C
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+
+              context "when that line was deleted between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, move_line_commit) }
+                let(:new_diff_refs) { diff_refs(move_line_commit, delete_line_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 3) }
+
+                # old diff:
+                #   1 + BB
+                #   2 + A
+                #   3 + C
+                #
+                # new diff:
+                # 1 1   BB
+                # 2 2   A
+                # 3   - C
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+            end
+          end
+        end
+
+        context "when the file is renamed in the new diff" do
+          context "when the position pointed at an added line in the old diff" do
+            context "when the file's content was unchanged between the old and the new diff" do
+              let(:old_diff_refs) { diff_refs(initial_commit, delete_line_commit) }
+              let(:new_diff_refs) { diff_refs(delete_line_commit, rename_file_commit) }
+              let(:old_position) { position(new_path: file_name, new_line: 2) }
+
+              # old diff:
+              #   1 + BB
+              #   2 + A
+              #
+              # new diff:
+              # file_name -> new_file_name
+              # 1 1   BB
+              # 2 2   A
+
+              it "returns the new position" do
+                expect_new_position(
+                  old_path: file_name,
+                  new_path: new_file_name,
+                  old_line: old_position.new_line,
+                  new_line: old_position.new_line
+                )
+              end
+            end
+
+            context "when the file's content was changed between the old and the new diff" do
+              context "when that line was unchanged between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, delete_line_commit) }
+                let(:new_diff_refs) { diff_refs(delete_line_commit, update_line_again_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 1) }
+
+                # old diff:
+                #   1 + BB
+                #   2 + A
+                #
+                # new diff:
+                # file_name -> new_file_name
+                # 1 1   BB
+                # 2   - A
+                #   2 + AA
+
+                it "returns the new position" do
+                  expect_new_position(
+                    old_path: file_name,
+                    new_path: new_file_name,
+                    old_line: old_position.new_line,
+                    new_line: old_position.new_line
+                  )
+                end
+              end
+
+              context "when that line was moved between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, delete_line_commit) }
+                let(:new_diff_refs) { diff_refs(delete_line_commit, move_line_again_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 1) }
+
+                # old diff:
+                #   1 + BB
+                #   2 + A
+                #
+                # new diff:
+                # file_name -> new_file_name
+                #   1 + AA
+                # 1 2   BB
+                # 2   - A
+
+                it "returns the new position" do
+                  expect_new_position(
+                    old_path: file_name,
+                    new_path: new_file_name,
+                    old_line: 1,
+                    new_line: 2
+                  )
+                end
+              end
+
+              context "when that line was changed between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, delete_line_commit) }
+                let(:new_diff_refs) { diff_refs(delete_line_commit, update_line_again_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 2) }
+
+                # old diff:
+                #   1 + BB
+                #   2 + A
+                #
+                # new diff:
+                # file_name -> new_file_name
+                # 1 1   BB
+                # 2   - A
+                #   2 + AA
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+
+              context "when that line was deleted between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, delete_line_commit) }
+                let(:new_diff_refs) { diff_refs(delete_line_commit, delete_line_again_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 1) }
+
+                # old diff:
+                #   1 + BB
+                #   2 + A
+                #
+                # new diff:
+                # file_name -> new_file_name
+                # 1   - BB
+                # 2   - A
+                #   1 + AA
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+            end
+          end
+        end
+
+        context "when the file is deleted in the new diff" do
+          context "when the position pointed at an added line in the old diff" do
+            context "when the file's content was unchanged between the old and the new diff" do
+              let(:old_diff_refs) { diff_refs(initial_commit, delete_line_commit) }
+              let(:new_diff_refs) { diff_refs(delete_line_commit, delete_file_commit) }
+              let(:old_position) { position(new_path: file_name, new_line: 2) }
+
+              # old diff:
+              #   1 + BB
+              #   2 + A
+              #
+              # new diff:
+              # 1   - BB
+              # 2   - A
+
+              it "returns nil" do
+                expect(subject).to be_nil
+              end
+            end
+
+            context "when the file's content was changed between the old and the new diff" do
+              context "when that line was unchanged between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, move_line_commit) }
+                let(:new_diff_refs) { diff_refs(delete_line_commit, delete_file_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 2) }
+
+                # old diff:
+                #   1 + BB
+                #   2 + A
+                #   3 + C
+                #
+                # new diff:
+                # 1   - BB
+                # 2   - A
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+
+              context "when that line was moved between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, update_line_commit) }
+                let(:new_diff_refs) { diff_refs(move_line_commit, delete_file_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 2) }
+
+                # old diff:
+                #   1 + A
+                #   2 + BB
+                #   3 + C
+                #
+                # new diff:
+                # 1   - BB
+                # 2   - A
+                # 3   - C
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+
+              context "when that line was changed between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, create_file_commit) }
+                let(:new_diff_refs) { diff_refs(update_line_commit, delete_file_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 2) }
+
+                # old diff:
+                #   1 + A
+                #   2 + B
+                #   3 + C
+                #
+                # new diff:
+                # 1   - A
+                # 2   - BB
+                # 3   - C
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+
+              context "when that line was deleted between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, move_line_commit) }
+                let(:new_diff_refs) { diff_refs(delete_line_commit, delete_file_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 3) }
+
+                # old diff:
+                #   1 + BB
+                #   2 + A
+                #   3 + C
+                #
+                # new diff:
+                # 1   - BB
+                # 2   - A
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+            end
+          end
+        end
+
+        context "when the file is unchanged in the new diff" do
+          context "when the position pointed at an added line in the old diff" do
+            context "when the file's content was unchanged between the old and the new diff" do
+              let(:old_diff_refs) { diff_refs(initial_commit, create_file_commit) }
+              let(:new_diff_refs) { diff_refs(create_file_commit, create_second_file_commit) }
+              let(:old_position) { position(new_path: file_name, new_line: 2) }
+
+              # old diff:
+              #   1 + A
+              #   2 + B
+              #   3 + C
+              #
+              # new diff:
+              # 1 1   A
+              # 2 2   B
+              # 3 3   C
+
+              it "returns nil" do
+                expect(subject).to be_nil
+              end
+            end
+
+            context "when the file's content was changed between the old and the new diff" do
+              context "when that line was unchanged between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, create_file_commit) }
+                let(:new_diff_refs) { diff_refs(update_line_commit, update_second_file_line_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 1) }
+
+                # old diff:
+                #   1 + A
+                #   2 + B
+                #   3 + C
+                #
+                # new diff:
+                # 1 1   A
+                # 2 2   BB
+                # 3 3   C
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+
+              context "when that line was moved between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, update_line_commit) }
+                let(:new_diff_refs) { diff_refs(move_line_commit, move_second_file_line_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 2) }
+
+                # old diff:
+                #   1 + A
+                #   2 + BB
+                #   3 + C
+                #
+                # new diff:
+                # 1 1   BB
+                # 2 2   A
+                # 3 3   C
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+
+              context "when that line was changed between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, create_file_commit) }
+                let(:new_diff_refs) { diff_refs(update_line_commit, update_second_file_line_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 2) }
+
+                # old diff:
+                #   1 + A
+                #   2 + B
+                #   3 + C
+                #
+                # new diff:
+                # 1 1   A
+                # 2 2   BB
+                # 3 3   C
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+
+              context "when that line was deleted between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(initial_commit, move_line_commit) }
+                let(:new_diff_refs) { diff_refs(delete_line_commit, delete_second_file_line_commit) }
+                let(:old_position) { position(new_path: file_name, new_line: 3) }
+
+                # old diff:
+                #   1 + BB
+                #   2 + A
+                #   3 + C
+                #
+                # new diff:
+                # 1 1   BB
+                # 2 2   A
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+            end
+          end
+        end
+      end
+
+      context "when the file was changed in the old diff" do
+        context "when the file is created in the new diff" do
+          context "when the position pointed at an added line in the old diff" do
+            context "when the file's content was unchanged between the old and the new diff" do
+              let(:old_diff_refs) { diff_refs(create_file_commit, update_line_commit) }
+              let(:new_diff_refs) { diff_refs(initial_commit, update_line_commit) }
+              let(:old_position) { position(old_path: file_name, new_path: file_name, new_line: 2) }
+
+              # old diff:
+              # 1 1   A
+              # 2   - B
+              #   2 + BB
+              # 3 3   C
+              #
+              # new diff:
+              #   1 + A
+              #   2 + BB
+              #   3 + C
+
+              it "returns the new position" do
+                expect_new_position(
+                  new_path: old_position.new_path,
+                  old_line: nil,
+                  new_line: old_position.new_line
+                )
+              end
+            end
+
+            context "when the file's content was changed between the old and the new diff" do
+              context "when that line was unchanged between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(create_file_commit, move_line_commit) }
+                let(:new_diff_refs) { diff_refs(initial_commit, move_line_commit) }
+                let(:old_position) { position(old_path: file_name, new_path: file_name, new_line: 1) }
+
+                # old diff:
+                #   1 + BB
+                # 1 2   A
+                # 2   - B
+                # 3 3   C
+                #
+                # new diff:
+                #   1 + BB
+                #   2 + A
+
+                it "returns the new position" do
+                  expect_new_position(
+                    new_path: old_position.new_path,
+                    old_line: nil,
+                    new_line: old_position.new_line
+                  )
+                end
+              end
+
+              context "when that line was moved between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(create_file_commit, update_line_commit) }
+                let(:new_diff_refs) { diff_refs(initial_commit, move_line_commit) }
+                let(:old_position) { position(old_path: file_name, new_path: file_name, new_line: 2) }
+
+                # old diff:
+                # 1 1   A
+                # 2   - B
+                #   2 + BB
+                # 3 3   C
+                #
+                # new diff:
+                #   1 + BB
+                #   2 + A
+                #   3 + C
+
+                it "returns the new position" do
+                  expect_new_position(
+                    new_path: old_position.new_path,
+                    old_line: nil,
+                    new_line: 1
+                  )
+                end
+              end
+
+              context "when that line was changed or deleted between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(create_file_commit, move_line_commit) }
+                let(:new_diff_refs) { diff_refs(initial_commit, create_file_commit) }
+                let(:old_position) { position(old_path: file_name, new_path: file_name, new_line: 1) }
+
+                # old diff:
+                #   1 + BB
+                # 1 2   A
+                # 2   - B
+                # 3 3   C
+                #
+                # new diff:
+                #   1 + A
+                #   2 + B
+                #   3 + C
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+            end
+          end
+
+          context "when the position pointed at a deleted line in the old diff" do
+            let(:old_diff_refs) { diff_refs(create_file_commit, update_line_commit) }
+            let(:new_diff_refs) { diff_refs(initial_commit, update_line_commit) }
+            let(:old_position) { position(old_path: file_name, new_path: file_name, old_line: 2) }
+
+            # old diff:
+            # 1 1   A
+            # 2   - B
+            #   2 + BB
+            # 3 3   C
+            #
+            # new diff:
+            #   1 + A
+            #   2 + BB
+            #   3 + C
+
+            it "returns nil" do
+              expect(subject).to be_nil
+            end
+          end
+
+          context "when the position pointed at an unchanged line in the old diff" do
+            context "when the file's content was unchanged between the old and the new diff" do
+              let(:old_diff_refs) { diff_refs(create_file_commit, update_line_commit) }
+              let(:new_diff_refs) { diff_refs(initial_commit, update_line_commit) }
+              let(:old_position) { position(old_path: file_name, new_path: file_name, old_line: 1, new_line: 1) }
+
+              # old diff:
+              # 1 1   A
+              # 2   - B
+              #   2 + BB
+              # 3 3   C
+              #
+              # new diff:
+              #   1 + A
+              #   2 + BB
+              #   3 + C
+
+              it "returns the new position" do
+                expect_new_position(
+                  new_path: old_position.new_path,
+                  old_line: nil,
+                  new_line: old_position.new_line
+                )
+              end
+            end
+
+            context "when the file's content was changed between the old and the new diff" do
+              context "when that line was unchanged between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(create_file_commit, move_line_commit) }
+                let(:new_diff_refs) { diff_refs(initial_commit, move_line_commit) }
+                let(:old_position) { position(old_path: file_name, new_path: file_name, old_line: 1, new_line: 2) }
+
+                # old diff:
+                #   1 + BB
+                # 1 2   A
+                # 2   - B
+                # 3 3   C
+                #
+                # new diff:
+                #   1 + BB
+                #   2 + A
+
+                it "returns the new position" do
+                  expect_new_position(
+                    new_path: old_position.new_path,
+                    old_line: nil,
+                    new_line: old_position.new_line
+                  )
+                end
+              end
+
+              context "when that line was moved between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(move_line_commit, delete_line_commit) }
+                let(:new_diff_refs) { diff_refs(initial_commit, update_line_commit) }
+                let(:old_position) { position(old_path: file_name, new_path: file_name, old_line: 2, new_line: 2) }
+
+                # old diff:
+                # 1 1   BB
+                # 2 2   A
+                # 3   - C
+                #
+                # new diff:
+                #   1 + A
+                #   2 + BB
+                #   3 + C
+
+                it "returns the new position" do
+                  expect_new_position(
+                    new_path: old_position.new_path,
+                    old_line: nil,
+                    new_line: 1
+                  )
+                end
+              end
+
+              context "when that line was changed or deleted between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(create_file_commit, move_line_commit) }
+                let(:new_diff_refs) { diff_refs(initial_commit, delete_line_commit) }
+                let(:old_position) { position(old_path: file_name, new_path: file_name, old_line: 3, new_line: 3) }
+
+                # old diff:
+                #   1 + BB
+                # 1 2   A
+                # 2   - B
+                # 3 3   C
+                #
+                # new diff:
+                #   1 + A
+                #   2 + B
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+            end
+          end
+        end
+
+        context "when the file is changed in the new diff" do
+          context "when the position pointed at an added line in the old diff" do
+            context "when the file's content was unchanged between the old and the new diff" do
+              let(:old_diff_refs) { diff_refs(create_file_commit, update_line_commit) }
+              let(:new_diff_refs) { diff_refs(create_file_commit, update_second_file_line_commit) }
+              let(:old_position) { position(old_path: file_name, new_path: file_name, new_line: 2) }
+
+              # old diff:
+              # 1 1   A
+              # 2   - B
+              #   2 + BB
+              # 3 3   C
+              #
+              # new diff:
+              # 1 1   A
+              # 2   - B
+              #   2 + BB
+              # 3 3   C
+
+              it "returns the new position" do
+                expect_new_position(
+                  old_path: old_position.old_path,
+                  new_path: old_position.new_path,
+                  old_line: nil,
+                  new_line: old_position.new_line
+                )
+              end
+            end
+
+            context "when the file's content was changed between the old and the new diff" do
+              context "when that line was unchanged between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(create_file_commit, move_line_commit) }
+                let(:new_diff_refs) { diff_refs(move_line_commit, delete_line_commit) }
+                let(:old_position) { position(old_path: file_name, new_path: file_name, new_line: 1) }
+
+                # old diff:
+                #   1 + BB
+                # 1 2   A
+                # 2   - B
+                # 3 3   C
+                #
+                # new diff:
+                # 1 1   BB
+                # 2 2   A
+                # 3   - C
+
+                it "returns the new position" do
+                  expect_new_position(
+                    old_path: old_position.old_path,
+                    new_path: old_position.new_path,
+                    old_line: 1,
+                    new_line: 1
+                  )
+                end
+              end
+
+              context "when that line was moved between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(create_file_commit, update_line_commit) }
+                let(:new_diff_refs) { diff_refs(update_line_commit, move_line_commit) }
+                let(:old_position) { position(old_path: file_name, new_path: file_name, new_line: 2) }
+
+                # old diff:
+                # 1 1   A
+                # 2   - B
+                #   2 + BB
+                # 3 3   C
+                #
+                # new diff:
+                # 1   - A
+                # 2 1   BB
+                #   2 + A
+                # 3 3   C
+
+                it "returns the new position" do
+                  expect_new_position(
+                    old_path: old_position.old_path,
+                    new_path: old_position.new_path,
+                    old_line: 2,
+                    new_line: 1
+                  )
+                end
+              end
+
+              context "when that line was changed or deleted between the old and the new diff" do
+                let(:old_diff_refs) { diff_refs(create_file_commit, move_line_commit) }
+                let(:new_diff_refs) { diff_refs(create_file_commit, update_line_commit) }
+                let(:old_position) { position(old_path: file_name, new_path: file_name, new_line: 1) }
+
+                # old diff:
+                #   1 + BB
+                # 1 2   A
+                # 2   - B
+                # 3 3   C
+                #
+                # new diff:
+                # 1 1   A
+                # 2   - B
+                #   2 + BB
+                # 3 3   C
+
+                it "returns nil" do
+                  expect(subject).to be_nil
+                end
+              end
+            end
+          end
+
+          context "when the position pointed at a deleted line in the old diff" do
+            context "when the file's content was unchanged between the old and the new diff" do
+              let(:old_diff_refs) { diff_refs(create_file_commit, update_line_commit) }
+              let(:new_diff_refs) { diff_refs(create_file_commit, update_second_file_line_commit) }
+              let(:old_position) { position(old_path: file_name, new_path: file_name, old_line: 2) }
+
+              # old diff:
+              # 1 1   A
+              # 2   - B
+              #   2 + BB
+              # 3 3   C
+              #
+              # new diff:
+              # 1 1   A
+              # 2   - B
+              #   2 + BB
+              # 3 3   C
+
+              it "returns the new position" do
+                expect_new_position(
+                  old_path: old_position.old_path,
+                  new_path: old_position.new_path,
+                  old_line: old_position.old_line,
+                  new_line: nil
+                )
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+
+  describe "typical use scenarios" do
+    let(:second_branch_name) { "#{branch_name}-2" }
+
+    def expect_positions(old_attrs, new_attrs)
+      old_positions = old_attrs.map do |old_attrs|
+        position(old_attrs)
+      end
+
+      new_positions = old_positions.map do |old_position|
+        position_tracer.trace(old_position)
+      end
+
+      new_positions.zip(new_attrs).each do |new_position, new_attrs|
+        expect_new_position(new_attrs, new_position)
+      end
+    end
+
+    let(:create_file_commit) do
+      initial_commit
+
+      create_file(
+        branch_name,
+        file_name,
+        <<-CONTENT.strip_heredoc
+          A
+          B
+          C
+          D
+          E
+          F
+        CONTENT
+      )
+    end
+
+    let(:second_create_file_commit) do
+      create_file_commit
+
+      create_branch(second_branch_name, branch_name)
+
+      update_file(
+        second_branch_name,
+        file_name,
+        <<-CONTENT.strip_heredoc
+          Z
+          Z
+          Z
+          A
+          B
+          C
+          D
+          E
+          F
+        CONTENT
+      )
+    end
+
+    let(:update_file_commit) do
+      second_create_file_commit
+
+      update_file(
+        branch_name,
+        file_name,
+        <<-CONTENT.strip_heredoc
+          A
+          C
+          DD
+          E
+          F
+          G
+        CONTENT
+      )
+    end
+
+    let(:update_file_again_commit) do
+      update_file_commit
+
+      update_file(
+        branch_name,
+        file_name,
+        <<-CONTENT.strip_heredoc
+          A
+          BB
+          C
+          D
+          E
+          FF
+          G
+        CONTENT
+      )
+    end
+
+    describe "simple push of new commit" do
+      let(:old_diff_refs) { diff_refs(create_file_commit, update_file_commit) }
+      let(:new_diff_refs) { diff_refs(create_file_commit, update_file_again_commit) }
+
+      # old diff:
+      # 1 1   A
+      # 2   - B
+      # 3 2   C
+      # 4   - D
+      #   3 + DD
+      # 5 4   E
+      # 6 5   F
+      #   6 + G
+      #
+      # new diff:
+      # 1 1   A
+      # 2   - B
+      #   2 + BB
+      # 3 3   C
+      # 4 4   D
+      # 5 5   E
+      # 6   - F
+      #   6 + FF
+      #   7 + G
+
+      it "returns the new positions" do
+        old_position_attrs = [
+          { old_path: file_name, new_path: file_name, old_line: 1, new_line: 1 }, #   A
+          { old_path: file_name,                      old_line: 2              }, # - B
+          { old_path: file_name, new_path: file_name, old_line: 3, new_line: 2 }, #   C
+          { old_path: file_name,                      old_line: 4              }, # - D
+          {                      new_path: file_name,              new_line: 3 }, # + DD
+          { old_path: file_name, new_path: file_name, old_line: 5, new_line: 4 }, #   E
+          { old_path: file_name, new_path: file_name, old_line: 6, new_line: 5 }, #   F
+          {                      new_path: file_name,              new_line: 6 }, # + G
+        ]
+
+        new_position_attrs = [
+          { old_path: file_name, new_path: file_name, old_line: 1, new_line: 1 },
+          { old_path: file_name,                      old_line: 2              },
+          { old_path: file_name, new_path: file_name, old_line: 3, new_line: 3 },
+          { old_path: file_name,                      old_line: 4, new_line: 4 },
+          nil,
+          { old_path: file_name, new_path: file_name, old_line: 5, new_line: 5 },
+          { old_path: file_name,                      old_line: 6              },
+          {                      new_path: file_name,              new_line: 7 },
+        ]
+
+        expect_positions(old_position_attrs, new_position_attrs)
+      end
+    end
+
+    describe "force push to overwrite last commit" do
+      let(:second_create_file_commit) do
+        create_file_commit
+
+        create_branch(second_branch_name, branch_name)
+
+        update_file(
+          second_branch_name,
+          file_name,
+          <<-CONTENT.strip_heredoc
+            A
+            BB
+            C
+            D
+            E
+            FF
+            G
+          CONTENT
+        )
+      end
+
+      let(:old_diff_refs) { diff_refs(create_file_commit, update_file_commit) }
+      let(:new_diff_refs) { diff_refs(create_file_commit, second_create_file_commit) }
+
+      # old diff:
+      # 1 1   A
+      # 2   - B
+      # 3 2   C
+      # 4   - D
+      #   3 + DD
+      # 5 4   E
+      # 6 5   F
+      #   6 + G
+      #
+      # new diff:
+      # 1 1   A
+      # 2   - B
+      #   2 + BB
+      # 3 3   C
+      # 4 4   D
+      # 5 5   E
+      # 6   - F
+      #   6 + FF
+      #   7 + G
+
+      it "returns the new positions" do
+        old_position_attrs = [
+          { old_path: file_name, new_path: file_name, old_line: 1, new_line: 1 }, #   A
+          { old_path: file_name,                      old_line: 2              }, # - B
+          { old_path: file_name, new_path: file_name, old_line: 3, new_line: 2 }, #   C
+          { old_path: file_name,                      old_line: 4              }, # - D
+          {                      new_path: file_name,              new_line: 3 }, # + DD
+          { old_path: file_name, new_path: file_name, old_line: 5, new_line: 4 }, #   E
+          { old_path: file_name, new_path: file_name, old_line: 6, new_line: 5 }, #   F
+          {                      new_path: file_name,              new_line: 6 }, # + G
+        ]
+
+        new_position_attrs = [
+          { old_path: file_name, new_path: file_name, old_line: 1, new_line: 1 },
+          { old_path: file_name,                      old_line: 2              },
+          { old_path: file_name, new_path: file_name, old_line: 3, new_line: 3 },
+          { old_path: file_name,                      old_line: 4, new_line: 4 },
+          nil,
+          { old_path: file_name, new_path: file_name, old_line: 5, new_line: 5 },
+          { old_path: file_name,                      old_line: 6              },
+          {                      new_path: file_name,              new_line: 7 },
+        ]
+
+        expect_positions(old_position_attrs, new_position_attrs)
+      end
+    end
+
+    describe "force push to delete last commit" do
+      let(:old_diff_refs) { diff_refs(create_file_commit, update_file_again_commit) }
+      let(:new_diff_refs) { diff_refs(create_file_commit, update_file_commit) }
+
+      # old diff:
+      # 1 1   A
+      # 2   - B
+      #   2 + BB
+      # 3 3   C
+      # 4 4   D
+      # 5 5   E
+      # 6   - F
+      #   6 + FF
+      #   7 + G
+      #
+      # new diff:
+      # 1 1   A
+      # 2   - B
+      # 3 2   C
+      # 4   - D
+      #   3 + DD
+      # 5 4   E
+      # 6 5   F
+      #   6 + G
+
+      it "returns the new positions" do
+        old_position_attrs = [
+          { old_path: file_name, new_path: file_name, old_line: 1, new_line: 1 }, #   A
+          { old_path: file_name,                      old_line: 2              }, # - B
+          {                      new_path: file_name,              new_line: 2 }, # + BB
+          { old_path: file_name, new_path: file_name, old_line: 3, new_line: 3 }, #   C
+          { old_path: file_name, new_path: file_name, old_line: 4, new_line: 4 }, #   D
+          { old_path: file_name, new_path: file_name, old_line: 5, new_line: 5 }, #   E
+          { old_path: file_name,                      old_line: 6              }, # - F
+          {                      new_path: file_name,              new_line: 6 }, # + FF
+          {                      new_path: file_name,              new_line: 7 }, # + G
+        ]
+
+        new_position_attrs = [
+          { old_path: file_name, new_path: file_name, old_line: 1, new_line: 1 },
+          { old_path: file_name,                      old_line: 2              },
+          nil,
+          { old_path: file_name, new_path: file_name, old_line: 3, new_line: 2 },
+          { old_path: file_name,                      old_line: 4              },
+          { old_path: file_name, new_path: file_name, old_line: 5, new_line: 4 },
+          { old_path: file_name, new_path: file_name, old_line: 6, new_line: 5 },
+          nil,
+          {                      new_path: file_name,              new_line: 6 },
+        ]
+
+        expect_positions(old_position_attrs, new_position_attrs)
+      end
+    end
+
+    describe "rebase on top of target branch" do
+      let(:second_update_file_commit) do
+        update_file_commit
+
+        update_file(
+          second_branch_name,
+          file_name,
+          <<-CONTENT.strip_heredoc
+            Z
+            Z
+            Z
+            A
+            C
+            DD
+            E
+            F
+            G
+          CONTENT
+        )
+      end
+
+      let(:update_file_again_commit) do
+        second_update_file_commit
+
+        update_file(
+          branch_name,
+          file_name,
+          <<-CONTENT.strip_heredoc
+            A
+            BB
+            C
+            D
+            E
+            FF
+            G
+          CONTENT
+        )
+      end
+
+      let(:overwrite_update_file_again_commit) do
+        update_file_again_commit
+
+        update_file(
+          second_branch_name,
+          file_name,
+          <<-CONTENT.strip_heredoc
+            Z
+            Z
+            Z
+            A
+            BB
+            C
+            D
+            E
+            FF
+            G
+          CONTENT
+        )
+      end
+
+      let(:old_diff_refs) { diff_refs(create_file_commit, update_file_again_commit) }
+      let(:new_diff_refs) { diff_refs(create_file_commit, overwrite_update_file_again_commit) }
+
+      # old diff:
+      # 1 1   A
+      # 2   - B
+      #   2 + BB
+      # 3 3   C
+      # 4 4   D
+      # 5 5   E
+      # 6   - F
+      #   6 + FF
+      #   7 + G
+      #
+      # new diff:
+      #   1 + Z
+      #   2 + Z
+      #   3 + Z
+      # 1 4   A
+      # 2   - B
+      #   5 + BB
+      # 3 6   C
+      # 4 7   D
+      # 5 8   E
+      # 6   - F
+      #   9 + FF
+      #   0 + G
+
+      it "returns the new positions" do
+        old_position_attrs = [
+          { old_path: file_name, new_path: file_name, old_line: 1, new_line: 1 }, #   A
+          { old_path: file_name,                      old_line: 2              }, # - B
+          {                      new_path: file_name,              new_line: 2 }, # + BB
+          { old_path: file_name, new_path: file_name, old_line: 3, new_line: 3 }, #   C
+          { old_path: file_name, new_path: file_name, old_line: 4, new_line: 4 }, #   D
+          { old_path: file_name, new_path: file_name, old_line: 5, new_line: 5 }, #   E
+          { old_path: file_name,                      old_line: 6              }, # - F
+          {                      new_path: file_name,              new_line: 6 }, # + FF
+          {                      new_path: file_name,              new_line: 7 }, # + G
+        ]
+
+        new_position_attrs = [
+          { old_path: file_name, new_path: file_name, old_line: 1, new_line: 4 }, #   A
+          { old_path: file_name,                      old_line: 2              }, # - B
+          {                      new_path: file_name,              new_line: 5 }, # + BB
+          { old_path: file_name, new_path: file_name, old_line: 3, new_line: 6 }, #   C
+          { old_path: file_name, new_path: file_name, old_line: 4, new_line: 7 }, #   D
+          { old_path: file_name, new_path: file_name, old_line: 5, new_line: 8 }, #   E
+          { old_path: file_name,                      old_line: 6              }, # - F
+          {                      new_path: file_name,              new_line: 9 }, # + FF
+          {                      new_path: file_name,              new_line: 10 }, # + G
+        ]
+
+        expect_positions(old_position_attrs, new_position_attrs)
+      end
+    end
+
+    describe "merge of target branch" do
+      let(:merge_commit) do
+        update_file_again_commit
+
+        committer = repository.user_to_committer(current_user)
+
+        options = {
+          message: "Merge branches",
+          author: committer,
+          committer: committer
+        }
+
+        repository.merge(current_user, second_create_file_commit.sha, branch_name, options)
+        project.commit(branch_name)
+      end
+
+      let(:old_diff_refs) { diff_refs(create_file_commit, update_file_again_commit) }
+      let(:new_diff_refs) { diff_refs(create_file_commit, merge_commit) }
+
+      # old diff:
+      # 1 1   A
+      # 2   - B
+      #   2 + BB
+      # 3 3   C
+      # 4 4   D
+      # 5 5   E
+      # 6   - F
+      #   6 + FF
+      #   7 + G
+      #
+      # new diff:
+      #   1 + Z
+      #   2 + Z
+      #   3 + Z
+      # 1 4   A
+      # 2   - B
+      #   5 + BB
+      # 3 6   C
+      # 4 7   D
+      # 5 8   E
+      # 6   - F
+      #   9 + FF
+      #   0 + G
+
+      it "returns the new positions" do
+        old_position_attrs = [
+          { old_path: file_name, new_path: file_name, old_line: 1, new_line: 1 }, #   A
+          { old_path: file_name,                      old_line: 2              }, # - B
+          {                      new_path: file_name,              new_line: 2 }, # + BB
+          { old_path: file_name, new_path: file_name, old_line: 3, new_line: 3 }, #   C
+          { old_path: file_name, new_path: file_name, old_line: 4, new_line: 4 }, #   D
+          { old_path: file_name, new_path: file_name, old_line: 5, new_line: 5 }, #   E
+          { old_path: file_name,                      old_line: 6              }, # - F
+          {                      new_path: file_name,              new_line: 6 }, # + FF
+          {                      new_path: file_name,              new_line: 7 }, # + G
+        ]
+
+        new_position_attrs = [
+          { old_path: file_name, new_path: file_name, old_line: 1, new_line: 4 }, #   A
+          { old_path: file_name,                      old_line: 2              }, # - B
+          {                      new_path: file_name,              new_line: 5 }, # + BB
+          { old_path: file_name, new_path: file_name, old_line: 3, new_line: 6 }, #   C
+          { old_path: file_name, new_path: file_name, old_line: 4, new_line: 7 }, #   D
+          { old_path: file_name, new_path: file_name, old_line: 5, new_line: 8 }, #   E
+          { old_path: file_name,                      old_line: 6              }, # - F
+          {                      new_path: file_name,              new_line: 9 }, # + FF
+          {                      new_path: file_name,              new_line: 10 }, # + G
+        ]
+
+        expect_positions(old_position_attrs, new_position_attrs)
+      end
+    end
+
+    describe "changing target branch" do
+      let(:old_diff_refs) { diff_refs(create_file_commit, update_file_again_commit) }
+      let(:new_diff_refs) { diff_refs(update_file_commit, update_file_again_commit) }
+
+      # old diff:
+      # 1 1   A
+      # 2   - B
+      #   2 + BB
+      # 3 3   C
+      # 4 4   D
+      # 5 5   E
+      # 6   - F
+      #   6 + FF
+      #   7 + G
+      #
+      # new diff:
+      # 1 1   A
+      #   2 + BB
+      # 2 3   C
+      # 3   - DD
+      #   4 + D
+      # 4 5   E
+      # 5   - F
+      #   6 + FF
+      #   7   G
+
+      it "returns the new positions" do
+        old_position_attrs = [
+          { old_path: file_name, new_path: file_name, old_line: 1, new_line: 1 }, #   A
+          { old_path: file_name,                      old_line: 2              }, # - B
+          {                      new_path: file_name,              new_line: 2 }, # + BB
+          { old_path: file_name, new_path: file_name, old_line: 3, new_line: 3 }, #   C
+          { old_path: file_name, new_path: file_name, old_line: 4, new_line: 4 }, #   D
+          { old_path: file_name, new_path: file_name, old_line: 5, new_line: 5 }, #   E
+          { old_path: file_name,                      old_line: 6              }, # - F
+          {                      new_path: file_name,              new_line: 6 }, # + FF
+          {                      new_path: file_name,              new_line: 7 }, # + G
+        ]
+
+        new_position_attrs = [
+          { old_path: file_name, new_path: file_name, old_line: 1, new_line: 1 },
+          nil,
+          {                      new_path: file_name,              new_line: 2 },
+          { old_path: file_name, new_path: file_name, old_line: 2, new_line: 3 },
+          {                      new_path: file_name,              new_line: 4 },
+          { old_path: file_name, new_path: file_name, old_line: 4, new_line: 5 },
+          { old_path: file_name,                      old_line: 5              },
+          {                      new_path: file_name,              new_line: 6 },
+          {                      new_path: file_name,              new_line: 7 },
+        ]
+
+        expect_positions(old_position_attrs, new_position_attrs)
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/git/hook_spec.rb b/spec/lib/gitlab/git/hook_spec.rb
new file mode 100644
index 00000000000..a15aa173fbd
--- /dev/null
+++ b/spec/lib/gitlab/git/hook_spec.rb
@@ -0,0 +1,70 @@
+require 'spec_helper'
+require 'fileutils'
+
+describe Gitlab::Git::Hook, lib: true do
+  describe "#trigger" do
+    let(:project) { create(:project) }
+    let(:user) { create(:user) }
+
+    def create_hook(name)
+      FileUtils.mkdir_p(File.join(project.repository.path, 'hooks'))
+      File.open(File.join(project.repository.path, 'hooks', name), 'w', 0755) do |f|
+        f.write('exit 0')
+      end
+    end
+
+    def create_failing_hook(name)
+      FileUtils.mkdir_p(File.join(project.repository.path, 'hooks'))
+      File.open(File.join(project.repository.path, 'hooks', name), 'w', 0755) do |f|
+        f.write(<<-HOOK)
+          echo 'regular message from the hook'
+          echo 'error message from the hook' 1>&2
+          exit 1
+        HOOK
+      end
+    end
+
+    ['pre-receive', 'post-receive', 'update'].each do |hook_name|
+
+      context "when triggering a #{hook_name} hook" do
+        context "when the hook is successful" do
+          it "returns success with no errors" do
+            create_hook(hook_name)
+            hook = Gitlab::Git::Hook.new(hook_name, project.repository.path)
+            blank = Gitlab::Git::BLANK_SHA
+            ref = Gitlab::Git::BRANCH_REF_PREFIX + 'new_branch'
+
+            status, errors = hook.trigger(Gitlab::GlId.gl_id(user), blank, blank, ref)
+            expect(status).to be true
+            expect(errors).to be_blank
+          end
+        end
+
+        context "when the hook is unsuccessful" do
+          it "returns failure with errors" do
+            create_failing_hook(hook_name)
+            hook = Gitlab::Git::Hook.new(hook_name, project.repository.path)
+            blank = Gitlab::Git::BLANK_SHA
+            ref = Gitlab::Git::BRANCH_REF_PREFIX + 'new_branch'
+
+            status, errors = hook.trigger(Gitlab::GlId.gl_id(user), blank, blank, ref)
+            expect(status).to be false
+            expect(errors).to eq("error message from the hook\n")
+          end
+        end
+      end
+    end
+
+    context "when the hook doesn't exist" do
+      it "returns success with no errors" do
+        hook = Gitlab::Git::Hook.new('unknown_hook', project.repository.path)
+        blank = Gitlab::Git::BLANK_SHA
+        ref = Gitlab::Git::BRANCH_REF_PREFIX + 'new_branch'
+
+        status, errors = hook.trigger(Gitlab::GlId.gl_id(user), blank, blank, ref)
+        expect(status).to be true
+        expect(errors).to be_nil
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/git_access_spec.rb b/spec/lib/gitlab/git_access_spec.rb
index 9b7986fa12d..c79ba11f782 100644
--- a/spec/lib/gitlab/git_access_spec.rb
+++ b/spec/lib/gitlab/git_access_spec.rb
@@ -1,7 +1,7 @@
 require 'spec_helper'
 
 describe Gitlab::GitAccess, lib: true do
-  let(:access) { Gitlab::GitAccess.new(actor, project) }
+  let(:access) { Gitlab::GitAccess.new(actor, project, 'web') }
   let(:project) { create(:project) }
   let(:user) { create(:user) }
   let(:actor) { user }
@@ -67,6 +67,43 @@ describe Gitlab::GitAccess, lib: true do
     end
   end
 
+  describe '#check with single protocols allowed' do
+    def disable_protocol(protocol)
+      settings = ::ApplicationSetting.create_from_defaults
+      settings.update_attribute(:enabled_git_access_protocol, protocol)
+    end
+
+    context 'ssh disabled' do
+      before do
+        disable_protocol('ssh')
+        @acc = Gitlab::GitAccess.new(actor, project, 'ssh')
+      end
+
+      it 'blocks ssh git push' do
+        expect(@acc.check('git-receive-pack').allowed?).to be_falsey
+      end
+
+      it 'blocks ssh git pull' do
+        expect(@acc.check('git-upload-pack').allowed?).to be_falsey
+      end
+    end
+
+    context 'http disabled' do
+      before do
+        disable_protocol('http')
+        @acc = Gitlab::GitAccess.new(actor, project, 'http')
+      end
+
+      it 'blocks http push' do
+        expect(@acc.check('git-receive-pack').allowed?).to be_falsey
+      end
+
+      it 'blocks http git pull' do
+        expect(@acc.check('git-upload-pack').allowed?).to be_falsey
+      end
+    end
+  end
+
   describe 'download_access_check' do
     describe 'master permissions' do
       before { project.team << [user, :master] }
diff --git a/spec/lib/gitlab/git_access_wiki_spec.rb b/spec/lib/gitlab/git_access_wiki_spec.rb
index 77ecfce6f17..4244b807d41 100644
--- a/spec/lib/gitlab/git_access_wiki_spec.rb
+++ b/spec/lib/gitlab/git_access_wiki_spec.rb
@@ -1,7 +1,7 @@
 require 'spec_helper'
 
 describe Gitlab::GitAccessWiki, lib: true do
-  let(:access) { Gitlab::GitAccessWiki.new(user, project) }
+  let(:access) { Gitlab::GitAccessWiki.new(user, project, 'web') }
   let(:project) { create(:project) }
   let(:user) { create(:user) }
 
diff --git a/spec/lib/gitlab/github_import/branch_formatter_spec.rb b/spec/lib/gitlab/github_import/branch_formatter_spec.rb
index 3cb634ba010..fc9d5204148 100644
--- a/spec/lib/gitlab/github_import/branch_formatter_spec.rb
+++ b/spec/lib/gitlab/github_import/branch_formatter_spec.rb
@@ -2,17 +2,18 @@ require 'spec_helper'
 
 describe Gitlab::GithubImport::BranchFormatter, lib: true do
   let(:project) { create(:project) }
+  let(:commit) { create(:commit, project: project) }
   let(:repo) { double }
   let(:raw) do
     {
       ref: 'feature',
       repo: repo,
-      sha: '2e5d3239642f9161dcbbc4b70a211a68e5e45e2b'
+      sha: commit.id
     }
   end
 
   describe '#exists?' do
-    it 'returns true when branch exists' do
+    it 'returns true when both branch, and commit exists' do
       branch = described_class.new(project, double(raw))
 
       expect(branch.exists?).to eq true
@@ -23,6 +24,12 @@ describe Gitlab::GithubImport::BranchFormatter, lib: true do
 
       expect(branch.exists?).to eq false
     end
+
+    it 'returns false when commit does not exist' do
+      branch = described_class.new(project, double(raw.merge(sha: '2e5d3239642f9161dcbbc4b70a211a68e5e45e2b')))
+
+      expect(branch.exists?).to eq false
+    end
   end
 
   describe '#name' do
@@ -33,7 +40,7 @@ describe Gitlab::GithubImport::BranchFormatter, lib: true do
     end
 
     it 'returns formatted ref when branch does not exist' do
-      branch = described_class.new(project, double(raw.merge(ref: 'removed-branch')))
+      branch = described_class.new(project, double(raw.merge(ref: 'removed-branch', sha: '2e5d3239642f9161dcbbc4b70a211a68e5e45e2b')))
 
       expect(branch.name).to eq 'removed-branch-2e5d3239'
     end
@@ -51,18 +58,18 @@ describe Gitlab::GithubImport::BranchFormatter, lib: true do
     it 'returns raw sha' do
       branch = described_class.new(project, double(raw))
 
-      expect(branch.sha).to eq '2e5d3239642f9161dcbbc4b70a211a68e5e45e2b'
+      expect(branch.sha).to eq commit.id
     end
   end
 
   describe '#valid?' do
-    it 'returns true when repository exists' do
+    it 'returns true when raw repo is present' do
       branch = described_class.new(project, double(raw))
 
       expect(branch.valid?).to eq true
     end
 
-    it 'returns false when repository does not exist' do
+    it 'returns false when raw repo is blank' do
       branch = described_class.new(project, double(raw.merge(repo: nil)))
 
       expect(branch.valid?).to eq false
diff --git a/spec/lib/gitlab/github_import/client_spec.rb b/spec/lib/gitlab/github_import/client_spec.rb
index 3b023a35446..613c47d55f1 100644
--- a/spec/lib/gitlab/github_import/client_spec.rb
+++ b/spec/lib/gitlab/github_import/client_spec.rb
@@ -61,4 +61,11 @@ describe Gitlab::GithubImport::Client, lib: true do
       expect(client.api.api_endpoint).to eq 'https://github.company.com/'
     end
   end
+
+  it 'does not raise error when rate limit is disabled' do
+    stub_request(:get, /api.github.com/)
+    allow(client.api).to receive(:rate_limit!).and_raise(Octokit::NotFound)
+
+    expect { client.issues }.not_to raise_error
+  end
 end
diff --git a/spec/lib/gitlab/github_import/pull_request_formatter_spec.rb b/spec/lib/gitlab/github_import/pull_request_formatter_spec.rb
index 120f59e6e71..79931ecd134 100644
--- a/spec/lib/gitlab/github_import/pull_request_formatter_spec.rb
+++ b/spec/lib/gitlab/github_import/pull_request_formatter_spec.rb
@@ -2,11 +2,13 @@ require 'spec_helper'
 
 describe Gitlab::GithubImport::PullRequestFormatter, lib: true do
   let(:project) { create(:project) }
+  let(:source_sha) { create(:commit, project: project).id }
+  let(:target_sha) { create(:commit, project: project, git_commit: RepoHelpers.another_sample_commit).id }
   let(:repository) { double(id: 1, fork: false) }
   let(:source_repo) { repository }
-  let(:source_branch) { double(ref: 'feature', repo: source_repo, sha: '2e5d3239642f9161dcbbc4b70a211a68e5e45e2b') }
+  let(:source_branch) { double(ref: 'feature', repo: source_repo, sha: source_sha) }
   let(:target_repo) { repository }
-  let(:target_branch) { double(ref: 'master', repo: target_repo, sha: '8ffb3c15a5475e59ae909384297fede4badcb4c7') }
+  let(:target_branch) { double(ref: 'master', repo: target_repo, sha: target_sha) }
   let(:octocat) { double(id: 123456, login: 'octocat') }
   let(:created_at) { DateTime.strptime('2011-01-26T19:01:12Z') }
   let(:updated_at) { DateTime.strptime('2011-01-27T19:01:12Z') }
@@ -41,10 +43,10 @@ describe Gitlab::GithubImport::PullRequestFormatter, lib: true do
           description: "*Created by: octocat*\n\nPlease pull these awesome changes",
           source_project: project,
           source_branch: 'feature',
-          head_source_sha: '2e5d3239642f9161dcbbc4b70a211a68e5e45e2b',
+          source_branch_sha: source_sha,
           target_project: project,
           target_branch: 'master',
-          base_target_sha: '8ffb3c15a5475e59ae909384297fede4badcb4c7',
+          target_branch_sha: target_sha,
           state: 'opened',
           milestone: nil,
           author_id: project.creator_id,
@@ -68,10 +70,10 @@ describe Gitlab::GithubImport::PullRequestFormatter, lib: true do
           description: "*Created by: octocat*\n\nPlease pull these awesome changes",
           source_project: project,
           source_branch: 'feature',
-          head_source_sha: '2e5d3239642f9161dcbbc4b70a211a68e5e45e2b',
+          source_branch_sha: source_sha,
           target_project: project,
           target_branch: 'master',
-          base_target_sha: '8ffb3c15a5475e59ae909384297fede4badcb4c7',
+          target_branch_sha: target_sha,
           state: 'closed',
           milestone: nil,
           author_id: project.creator_id,
@@ -95,10 +97,10 @@ describe Gitlab::GithubImport::PullRequestFormatter, lib: true do
           description: "*Created by: octocat*\n\nPlease pull these awesome changes",
           source_project: project,
           source_branch: 'feature',
-          head_source_sha: '2e5d3239642f9161dcbbc4b70a211a68e5e45e2b',
+          source_branch_sha: source_sha,
           target_project: project,
           target_branch: 'master',
-          base_target_sha: '8ffb3c15a5475e59ae909384297fede4badcb4c7',
+          target_branch_sha: target_sha,
           state: 'merged',
           milestone: nil,
           author_id: project.creator_id,
diff --git a/spec/lib/gitlab/gitlab_import/importer_spec.rb b/spec/lib/gitlab/gitlab_import/importer_spec.rb
new file mode 100644
index 00000000000..d3f1deb3837
--- /dev/null
+++ b/spec/lib/gitlab/gitlab_import/importer_spec.rb
@@ -0,0 +1,53 @@
+require 'spec_helper'
+
+describe Gitlab::GitlabImport::Importer, lib: true do
+  include ImportSpecHelper
+
+  describe '#execute' do
+    before do
+      stub_omniauth_provider('gitlab')
+      stub_request('issues', [
+        {
+          'id' => 2579857,
+          'iid' => 3,
+          'title' => 'Issue',
+          'description' => 'Lorem ipsum',
+          'state' => 'opened',
+          'author' => {
+            'id' => 283999,
+            'name' => 'John Doe'
+          }
+        }
+      ])
+      stub_request('issues/2579857/notes', [])
+    end
+
+    it 'persists issues' do
+      project = create(:empty_project, import_source: 'asd/vim')
+      project.build_import_data(credentials: { password: 'password' })
+
+      subject = described_class.new(project)
+      subject.execute
+
+      expected_attributes = {
+        iid: 3,
+        title: 'Issue',
+        description: "*Created by: John Doe*\n\nLorem ipsum",
+        state: 'opened',
+        author_id: project.creator_id
+      }
+
+      expect(project.issues.first).to have_attributes(expected_attributes)
+    end
+
+    def stub_request(path, body)
+      url = "https://gitlab.com/api/v3/projects/asd%2Fvim/#{path}?page=1&per_page=100"
+
+      WebMock.stub_request(:get, url).
+        to_return(
+          headers: { 'Content-Type' => 'application/json' },
+          body: body
+        )
+    end
+  end
+end
diff --git a/spec/lib/gitlab/graphs/commits_spec.rb b/spec/lib/gitlab/graphs/commits_spec.rb
new file mode 100644
index 00000000000..f5c064303ad
--- /dev/null
+++ b/spec/lib/gitlab/graphs/commits_spec.rb
@@ -0,0 +1,39 @@
+require 'spec_helper'
+
+describe Gitlab::Graphs::Commits, lib: true do
+  let!(:project) { create(:project, :public, :empty_repo) }
+
+  let!(:commit1) { create(:commit, git_commit: RepoHelpers.sample_commit, project: project, committed_date: Time.now) }
+  let!(:commit1_yesterday) { create(:commit, git_commit: RepoHelpers.sample_commit, project: project, committed_date: 1.day.ago)}
+
+  let!(:commit2) { create(:commit, git_commit: RepoHelpers.another_sample_commit, project: project, committed_date: Time.now) }
+
+  describe '#commit_per_day' do
+    context 'when range is only commits from today' do
+      subject { described_class.new([commit2, commit1]).commit_per_day }
+      it { is_expected.to eq 2 }
+    end
+  end
+
+  context 'when range is only commits from today' do
+    subject { described_class.new([commit2, commit1]) }
+    describe '#commit_per_day' do
+      it { expect(subject.commit_per_day).to eq 2 }
+    end
+
+    describe '#duration' do
+      it { expect(subject.duration).to eq 0 }
+    end
+  end
+
+  context 'with commits from yesterday and today' do
+    subject { described_class.new([commit2, commit1_yesterday]) }
+    describe '#commit_per_day' do
+      it { expect(subject.commit_per_day).to eq 1 }
+    end
+
+    describe '#duration' do
+      it { expect(subject.duration).to eq 1 }
+    end
+  end
+end
diff --git a/spec/lib/gitlab/import_export/import_export_spec.rb b/spec/lib/gitlab/import_export/import_export_spec.rb
new file mode 100644
index 00000000000..d6409a29550
--- /dev/null
+++ b/spec/lib/gitlab/import_export/import_export_spec.rb
@@ -0,0 +1,21 @@
+require 'spec_helper'
+
+describe Gitlab::ImportExport, services: true do
+  describe 'export filename' do
+    let(:project) { create(:project, :public, path: 'project-path') }
+
+    it 'contains the project path' do
+      expect(described_class.export_filename(project: project)).to include(project.path)
+    end
+
+    it 'contains the namespace path' do
+      expect(described_class.export_filename(project: project)).to include(project.namespace.path)
+    end
+
+    it 'does not go over a certain length' do
+      project.path = 'a' * 100
+
+      expect(described_class.export_filename(project: project).length).to be < 70
+    end
+  end
+end
diff --git a/spec/lib/gitlab/import_export/project.json b/spec/lib/gitlab/import_export/project.json
index 0b30e8c9b04..4113d829c3c 100644
--- a/spec/lib/gitlab/import_export/project.json
+++ b/spec/lib/gitlab/import_export/project.json
@@ -26,6 +26,7 @@
       "deleted_at": null,
       "due_date": null,
       "moved_to_id": null,
+      "test_ee_field": "test",
       "notes": [
         {
           "id": 351,
@@ -4208,7 +4209,18 @@
             "name": "User 4"
           },
           "events": [
-
+            {
+              "id": 529,
+              "target_type": "Note",
+              "target_id": 2521,
+              "title": "test levels",
+              "data": null,
+              "project_id": 4,
+              "created_at": "2016-07-07T14:35:12.128Z",
+              "updated_at": "2016-07-07T14:35:12.128Z",
+              "action": 6,
+              "author_id": 1
+            }
           ]
         },
         {
diff --git a/spec/lib/gitlab/import_export/project_tree_restorer_spec.rb b/spec/lib/gitlab/import_export/project_tree_restorer_spec.rb
index a72aaa44e82..877be300262 100644
--- a/spec/lib/gitlab/import_export/project_tree_restorer_spec.rb
+++ b/spec/lib/gitlab/import_export/project_tree_restorer_spec.rb
@@ -24,11 +24,35 @@ describe Gitlab::ImportExport::ProjectTreeRestorer, services: true do
         expect(Ci::Pipeline.first.notes).not_to be_empty
       end
 
-      it 'restores the correct event' do
+      it 'restores the correct event with symbolised data' do
         restored_project_json
 
         expect(Event.where.not(data: nil).first.data[:ref]).not_to be_empty
       end
+
+      it 'preserves updated_at on issues' do
+        restored_project_json
+
+        issue = Issue.where(description: 'Aliquam enim illo et possimus.').first
+
+        expect(issue.reload.updated_at.to_s).to eq('2016-06-14 15:02:47 UTC')
+      end
+
+      context 'event at forth level of the tree' do
+        let(:event) { Event.where(title: 'test levels').first }
+
+        before do
+          restored_project_json
+        end
+
+        it 'restores the event' do
+          expect(event).not_to be_nil
+        end
+
+        it 'event belongs to note, belongs to merge request, belongs to a project' do
+          expect(event.note.noteable.project).not_to be_nil
+        end
+      end
     end
   end
 end
diff --git a/spec/lib/gitlab/import_export/project_tree_saver_spec.rb b/spec/lib/gitlab/import_export/project_tree_saver_spec.rb
index a75eaa4d51f..1424de9e60b 100644
--- a/spec/lib/gitlab/import_export/project_tree_saver_spec.rb
+++ b/spec/lib/gitlab/import_export/project_tree_saver_spec.rb
@@ -125,7 +125,7 @@ describe Gitlab::ImportExport::ProjectTreeSaver, services: true do
 
     ci_pipeline = create(:ci_pipeline,
                        project: project,
-                       sha: merge_request.last_commit.id,
+                       sha: merge_request.diff_head_sha,
                        ref: merge_request.source_branch,
                        statuses: [commit_status])
 
diff --git a/spec/lib/gitlab/ldap/access_spec.rb b/spec/lib/gitlab/ldap/access_spec.rb
index f5b66b8156f..acd5394382c 100644
--- a/spec/lib/gitlab/ldap/access_spec.rb
+++ b/spec/lib/gitlab/ldap/access_spec.rb
@@ -4,7 +4,7 @@ describe Gitlab::LDAP::Access, lib: true do
   let(:access) { Gitlab::LDAP::Access.new user }
   let(:user) { create(:omniauth_user) }
 
-  describe :allowed? do
+  describe '#allowed?' do
     subject { access.allowed? }
 
     context 'when the user cannot be found' do
diff --git a/spec/lib/gitlab/ldap/user_spec.rb b/spec/lib/gitlab/ldap/user_spec.rb
index 03199a2523e..949f6e2b19a 100644
--- a/spec/lib/gitlab/ldap/user_spec.rb
+++ b/spec/lib/gitlab/ldap/user_spec.rb
@@ -25,7 +25,7 @@ describe Gitlab::LDAP::User, lib: true do
     OmniAuth::AuthHash.new(uid: 'my-uid', provider: 'ldapmain', info: info_upper_case)
   end
 
-  describe :changed? do
+  describe '#changed?' do
     it "marks existing ldap user as changed" do
       create(:omniauth_user, extern_uid: 'my-uid', provider: 'ldapmain')
       expect(ldap_user.changed?).to be_truthy
diff --git a/spec/lib/gitlab/metrics/subscribers/rails_cache_spec.rb b/spec/lib/gitlab/metrics/subscribers/rails_cache_spec.rb
index d824dc54438..d986c6fac43 100644
--- a/spec/lib/gitlab/metrics/subscribers/rails_cache_spec.rb
+++ b/spec/lib/gitlab/metrics/subscribers/rails_cache_spec.rb
@@ -13,6 +13,61 @@ describe Gitlab::Metrics::Subscribers::RailsCache do
 
       subscriber.cache_read(event)
     end
+
+    context 'with a transaction' do
+      before do
+        allow(subscriber).to receive(:current_transaction).
+          and_return(transaction)
+      end
+
+      context 'with hit event' do
+        let(:event) { double(:event, duration: 15.2, payload: { hit: true }) }
+
+        it 'increments the cache_read_hit count' do
+          expect(transaction).to receive(:increment).
+            with(:cache_read_hit_count, 1)
+          expect(transaction).to receive(:increment).
+            with(any_args).at_least(1) # Other calls
+
+          subscriber.cache_read(event)
+        end
+
+        context 'when super operation is fetch' do
+          let(:event) { double(:event, duration: 15.2, payload: { hit: true, super_operation: :fetch }) }
+
+          it 'does not increment cache read miss' do
+            expect(transaction).not_to receive(:increment).
+              with(:cache_read_hit_count, 1)
+
+            subscriber.cache_read(event)
+          end
+        end
+      end
+
+      context 'with miss event' do
+        let(:event) { double(:event, duration: 15.2, payload: { hit: false }) }
+
+        it 'increments the cache_read_miss count' do
+          expect(transaction).to receive(:increment).
+            with(:cache_read_miss_count, 1)
+          expect(transaction).to receive(:increment).
+            with(any_args).at_least(1) # Other calls
+
+          subscriber.cache_read(event)
+        end
+
+        context 'when super operation is fetch' do
+          let(:event) { double(:event, duration: 15.2, payload: { hit: false, super_operation: :fetch }) }
+
+          it 'does not increment cache read miss' do
+            expect(transaction).not_to receive(:increment).
+              with(:cache_read_miss_count, 1)
+
+            subscriber.cache_read(event)
+          end
+        end
+      end
+    end
   end
 
   describe '#cache_write' do
@@ -42,6 +97,54 @@ describe Gitlab::Metrics::Subscribers::RailsCache do
     end
   end
 
+  describe '#cache_fetch_hit' do
+    context 'without a transaction' do
+      it 'returns' do
+        expect(transaction).not_to receive(:increment)
+
+        subscriber.cache_fetch_hit(event)
+      end
+    end
+
+    context 'with a transaction' do
+      before do
+        allow(subscriber).to receive(:current_transaction).
+          and_return(transaction)
+      end
+
+      it 'increments the cache_read_hit count' do
+        expect(transaction).to receive(:increment).
+          with(:cache_read_hit_count, 1)
+
+        subscriber.cache_fetch_hit(event)
+      end
+    end
+  end
+
+  describe '#cache_generate' do
+    context 'without a transaction' do
+      it 'returns' do
+        expect(transaction).not_to receive(:increment)
+
+        subscriber.cache_generate(event)
+      end
+    end
+
+    context 'with a transaction' do
+      before do
+        allow(subscriber).to receive(:current_transaction).
+          and_return(transaction)
+      end
+
+      it 'increments the cache_fetch_miss count' do
+        expect(transaction).to receive(:increment).
+          with(:cache_read_miss_count, 1)
+
+        subscriber.cache_generate(event)
+      end
+    end
+  end
+
   describe '#increment' do
     context 'without a transaction' do
       it 'returns' do
diff --git a/spec/lib/gitlab/note_data_builder_spec.rb b/spec/lib/gitlab/note_data_builder_spec.rb
index e848d88182f..3d6bcdfd873 100644
--- a/spec/lib/gitlab/note_data_builder_spec.rb
+++ b/spec/lib/gitlab/note_data_builder_spec.rb
@@ -27,7 +27,7 @@ describe 'Gitlab::NoteDataBuilder', lib: true do
   end
 
   describe 'When asking for a note on commit diff' do
-    let(:note) { create(:note_on_commit_diff, project: project) }
+    let(:note) { create(:diff_note_on_commit, project: project) }
 
     it 'returns the note and commit-specific data' do
       expect(data).to have_key(:commit)
@@ -90,7 +90,7 @@ describe 'Gitlab::NoteDataBuilder', lib: true do
     end
 
     let(:note) do
-      create(:note_on_merge_request_diff, noteable: merge_request,
+      create(:diff_note_on_merge_request, noteable: merge_request,
                                           project: project)
     end
 
diff --git a/spec/lib/gitlab/url_builder_spec.rb b/spec/lib/gitlab/url_builder_spec.rb
index bf11472407a..a826b24419a 100644
--- a/spec/lib/gitlab/url_builder_spec.rb
+++ b/spec/lib/gitlab/url_builder_spec.rb
@@ -43,9 +43,9 @@ describe Gitlab::UrlBuilder, lib: true do
         end
       end
 
-      context 'on a CommitDiff' do
+      context 'on a Commit Diff' do
         it 'returns a proper URL' do
-          note = build_stubbed(:note_on_commit_diff)
+          note = build_stubbed(:diff_note_on_commit)
 
           url = described_class.build(note)
 
@@ -75,10 +75,10 @@ describe Gitlab::UrlBuilder, lib: true do
         end
       end
 
-      context 'on a MergeRequestDiff' do
+      context 'on a MergeRequest Diff' do
         it 'returns a proper URL' do
           merge_request = create(:merge_request, iid: 42)
-          note = build_stubbed(:note_on_merge_request_diff, noteable: merge_request)
+          note = build_stubbed(:diff_note_on_merge_request, noteable: merge_request)
 
           url = described_class.build(note)
 
diff --git a/spec/lib/gitlab/url_sanitizer_spec.rb b/spec/lib/gitlab/url_sanitizer_spec.rb
index 59024d3290b..2cb74629da8 100644
--- a/spec/lib/gitlab/url_sanitizer_spec.rb
+++ b/spec/lib/gitlab/url_sanitizer_spec.rb
@@ -45,6 +45,12 @@ describe Gitlab::UrlSanitizer, lib: true do
 
       expect(filtered_content).to include("user@server:project.git")
     end
+
+    it 'returns an empty string for invalid URLs' do
+      filtered_content = sanitize_url('ssh://')
+
+      expect(filtered_content).to include("repository '' not found")
+    end
   end
 
   describe '#sanitized_url' do