Store merge request ref_fetched status in the database34052-store-mr-ref-fetched-in-database

Closes #34052

7 files changed, 63 insertions, 3 deletions

diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index f581a25f093..c099d731082 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -771,6 +771,7 @@ class MergeRequest < ActiveRecord::Base
       "refs/heads/#{source_branch}",
       ref_path
     )
+    update_column(:ref_fetched, true)
   end
 
   def ref_path
@@ -778,7 +779,13 @@ class MergeRequest < ActiveRecord::Base
   end
 
   def ref_fetched?
-    project.repository.ref_exists?(ref_path)
+    super ||
+      begin
+        computed_value = project.repository.ref_exists?(ref_path)
+        update_column(:ref_fetched, true) if computed_value
+
+        computed_value
+      end
   end
 
   def ensure_ref_fetched
diff --git a/changelogs/unreleased/34052-store-mr-ref-fetched-in-database.yml b/changelogs/unreleased/34052-store-mr-ref-fetched-in-database.yml
new file mode 100644
index 00000000000..4bacfca7551
--- /dev/null
+++ b/changelogs/unreleased/34052-store-mr-ref-fetched-in-database.yml
@@ -0,0 +1,4 @@
+---
+title: Store merge request ref_fetched status in the database
+merge_request: 12424
+author:
diff --git a/db/migrate/20170622162730_add_ref_fetched_to_merge_request.rb b/db/migrate/20170622162730_add_ref_fetched_to_merge_request.rb
new file mode 100644
index 00000000000..62aa1a4b4f0
--- /dev/null
+++ b/db/migrate/20170622162730_add_ref_fetched_to_merge_request.rb
@@ -0,0 +1,9 @@
+class AddRefFetchedToMergeRequest < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def change
+    add_column :merge_requests, :ref_fetched, :boolean
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 028556bdccf..8c7440ee610 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20170621102400) do
+ActiveRecord::Schema.define(version: 20170622162730) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -770,6 +770,7 @@ ActiveRecord::Schema.define(version: 20170621102400) do
     t.datetime "last_edited_at"
     t.integer "last_edited_by_id"
     t.integer "head_pipeline_id"
+    t.boolean "ref_fetched"
   end
 
   add_index "merge_requests", ["assignee_id"], name: "index_merge_requests_on_assignee_id", using: :btree
diff --git a/lib/gitlab/import_export/import_export.yml b/lib/gitlab/import_export/import_export.yml
index 72183e8aad4..1860352c96d 100644
--- a/lib/gitlab/import_export/import_export.yml
+++ b/lib/gitlab/import_export/import_export.yml
@@ -99,6 +99,7 @@ excluded_attributes:
     - :milestone_id
   merge_requests:
     - :milestone_id
+    - :ref_fetched
   award_emoji:
     - :awardable_id
   statuses:
diff --git a/spec/lib/gitlab/import_export/fork_spec.rb b/spec/lib/gitlab/import_export/fork_spec.rb
index 42f3fc59f04..70796781532 100644
--- a/spec/lib/gitlab/import_export/fork_spec.rb
+++ b/spec/lib/gitlab/import_export/fork_spec.rb
@@ -44,6 +44,8 @@ describe 'forked project import', services: true do
   end
 
   it 'can access the MR' do
-    expect(project.merge_requests.first.ensure_ref_fetched.first).to include('refs/merge-requests/1/head')
+    project.merge_requests.first.ensure_ref_fetched
+
+    expect(project.repository.ref_exists?('refs/merge-requests/1/head')).to be_truthy
   end
 end
diff --git a/spec/models/merge_request_spec.rb b/spec/models/merge_request_spec.rb
index 1240c9745e2..bb5273074a2 100644
--- a/spec/models/merge_request_spec.rb
+++ b/spec/models/merge_request_spec.rb
@@ -1574,4 +1574,40 @@ describe MergeRequest, models: true do
       end
     end
   end
+
+  describe '#fetch_ref' do
+    it 'sets "ref_fetched" flag to true' do
+      subject.update!(ref_fetched: nil)
+
+      subject.fetch_ref
+
+      expect(subject.reload.ref_fetched).to be_truthy
+    end
+  end
+
+  describe '#ref_fetched?' do
+    it 'does not perform git operation when value is cached' do
+      subject.ref_fetched = true
+
+      expect_any_instance_of(Repository).not_to receive(:ref_exists?)
+      expect(subject.ref_fetched?).to be_truthy
+    end
+
+    it 'caches the value when ref exists but value is not cached' do
+      subject.update!(ref_fetched: nil)
+      allow_any_instance_of(Repository).to receive(:ref_exists?)
+        .and_return(true)
+
+      expect(subject.ref_fetched?).to be_truthy
+      expect(subject.reload.ref_fetched).to be_truthy
+    end
+
+    it 'returns false when ref does not exist' do
+      subject.update!(ref_fetched: nil)
+      allow_any_instance_of(Repository).to receive(:ref_exists?)
+        .and_return(false)
+
+      expect(subject.ref_fetched?).to be_falsey
+    end
+  end
 end