Allow setting content for resolutions

When reading conflicts:

1. Add a `type` field. `text` works as before, and has `sections`;
   `text-editor` is a file with ambiguous conflict markers that can only
   be resolved in an editor.
2. Add a `content_path` field pointing to a JSON representation of the
   file's content for a single file.
3. Hitting `content_path` returns a similar datastructure to the `file`,
   but without the `content_path` and `sections` fields, and with a
   `content` field containing the full contents of the file (with
   conflict markers).

When writing conflicts:

1. Instead of `sections` being at the top level, they are now in a
   `files` array. This matches the read format better.
2. The `files` array contains file hashes, each of which must contain:
   a. `new_path`
   b. `old_path`
   c. EITHER `sections` (which works as before) or `content` (with the
      full content of the resolved file).

1 files changed, 130 insertions, 9 deletions

diff --git a/spec/services/merge_requests/resolve_service_spec.rb b/spec/services/merge_requests/resolve_service_spec.rb
index d71932458fa..e667e93bea4 100644
--- a/spec/services/merge_requests/resolve_service_spec.rb
+++ b/spec/services/merge_requests/resolve_service_spec.rb
@@ -24,15 +24,26 @@ describe MergeRequests::ResolveService do
   end
 
   describe '#execute' do
-    context 'with valid params' do
+    context 'with section params' do
       let(:params) do
         {
-          sections: {
-            '2f6fcd96b88b36ce98c38da085c795a27d92a3dd_14_14' => 'head',
-            '6eb14e00385d2fb284765eb1cd8d420d33d63fc9_9_9' => 'head',
-            '6eb14e00385d2fb284765eb1cd8d420d33d63fc9_21_21' => 'origin',
-            '6eb14e00385d2fb284765eb1cd8d420d33d63fc9_49_49' => 'origin'
-          },
+          files: [
+            {
+              old_path: 'files/ruby/popen.rb',
+              new_path: 'files/ruby/popen.rb',
+              sections: {
+                '2f6fcd96b88b36ce98c38da085c795a27d92a3dd_14_14' => 'head'
+              }
+            }, {
+              old_path: 'files/ruby/regex.rb',
+              new_path: 'files/ruby/regex.rb',
+              sections: {
+                '6eb14e00385d2fb284765eb1cd8d420d33d63fc9_9_9' => 'head',
+                '6eb14e00385d2fb284765eb1cd8d420d33d63fc9_21_21' => 'origin',
+                '6eb14e00385d2fb284765eb1cd8d420d33d63fc9_49_49' => 'origin'
+              }
+            }
+          ],
           commit_message: 'This is a commit message!'
         }
       end
@@ -74,8 +85,96 @@ describe MergeRequests::ResolveService do
       end
     end
 
-    context 'when a resolution is missing' do
-      let(:invalid_params) { { sections: { '2f6fcd96b88b36ce98c38da085c795a27d92a3dd_14_14' => 'head' } } }
+    context 'with content and sections params' do
+      let(:popen_content) { "class Popen\nend" }
+
+      let(:params) do
+        {
+          files: [
+            {
+              old_path: 'files/ruby/popen.rb',
+              new_path: 'files/ruby/popen.rb',
+              content: popen_content
+            }, {
+              old_path: 'files/ruby/regex.rb',
+              new_path: 'files/ruby/regex.rb',
+              sections: {
+                '6eb14e00385d2fb284765eb1cd8d420d33d63fc9_9_9' => 'head',
+                '6eb14e00385d2fb284765eb1cd8d420d33d63fc9_21_21' => 'origin',
+                '6eb14e00385d2fb284765eb1cd8d420d33d63fc9_49_49' => 'origin'
+              }
+            }
+          ],
+          commit_message: 'This is a commit message!'
+        }
+      end
+
+      before do
+        MergeRequests::ResolveService.new(project, user, params).execute(merge_request)
+      end
+
+      it 'creates a commit with the message' do
+        expect(merge_request.source_branch_head.message).to eq(params[:commit_message])
+      end
+
+      it 'creates a commit with the correct parents' do
+        expect(merge_request.source_branch_head.parents.map(&:id)).
+          to eq(['1450cd639e0bc6721eb02800169e464f212cde06',
+                 '75284c70dd26c87f2a3fb65fd5a1f0b0138d3a6b'])
+      end
+
+      it 'sets the content to the content given' do
+        blob = merge_request.source_project.repository.blob_at(merge_request.source_branch_head.sha,
+                                                               'files/ruby/popen.rb')
+
+        expect(blob.data).to eq(popen_content)
+      end
+    end
+
+    context 'when a resolution section is missing' do
+      let(:invalid_params) do
+        {
+          files: [
+            {
+              old_path: 'files/ruby/popen.rb',
+              new_path: 'files/ruby/popen.rb',
+              content: ''
+            }, {
+              old_path: 'files/ruby/regex.rb',
+              new_path: 'files/ruby/regex.rb',
+              sections: { '6eb14e00385d2fb284765eb1cd8d420d33d63fc9_9_9' => 'head' }
+            }
+          ],
+          commit_message: 'This is a commit message!'
+        }
+      end
+
+      let(:service) { MergeRequests::ResolveService.new(project, user, invalid_params) }
+
+      it 'raises a MissingResolution error' do
+        expect { service.execute(merge_request) }.
+          to raise_error(Gitlab::Conflict::File::MissingResolution)
+      end
+    end
+
+    context 'when the content of a file is unchanged' do
+      let(:invalid_params) do
+        {
+          files: [
+            {
+              old_path: 'files/ruby/popen.rb',
+              new_path: 'files/ruby/popen.rb',
+              content: ''
+            }, {
+              old_path: 'files/ruby/regex.rb',
+              new_path: 'files/ruby/regex.rb',
+              content: merge_request.conflicts.file_for_path('files/ruby/regex.rb', 'files/ruby/regex.rb').content
+            }
+          ],
+          commit_message: 'This is a commit message!'
+        }
+      end
+
       let(:service) { MergeRequests::ResolveService.new(project, user, invalid_params) }
 
       it 'raises a MissingResolution error' do
@@ -83,5 +182,27 @@ describe MergeRequests::ResolveService do
           to raise_error(Gitlab::Conflict::File::MissingResolution)
       end
     end
+
+    context 'when a file is missing' do
+      let(:invalid_params) do
+        {
+          files: [
+            {
+              old_path: 'files/ruby/popen.rb',
+              new_path: 'files/ruby/popen.rb',
+              content: ''
+            }
+          ],
+          commit_message: 'This is a commit message!'
+        }
+      end
+
+      let(:service) { MergeRequests::ResolveService.new(project, user, invalid_params) }
+
+      it 'raises a MissingFiles error' do
+        expect { service.execute(merge_request) }.
+          to raise_error(MergeRequests::ResolveService::MissingFiles)
+      end
+    end
   end
 end