Expose comments on Noteables in GraphQL

This exposes `Note`s on Issues & MergeRequests using a
`Types::Notes::NoteableType` in GraphQL.

Exposing notes on a new type can be done by implementing the
`NoteableType` interface on the type. The presented object should
be a `Noteable`.

2 files changed, 114 insertions, 0 deletions

diff --git a/spec/requests/api/graphql/project/issue/notes_spec.rb b/spec/requests/api/graphql/project/issue/notes_spec.rb
new file mode 100644
index 00000000000..bfc89434370
--- /dev/null
+++ b/spec/requests/api/graphql/project/issue/notes_spec.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'getting notes for an issue' do
+  include GraphqlHelpers
+
+  let(:noteable) { create(:issue) }
+  let(:noteable_data) { graphql_data['project']['issue'] }
+
+  def noteable_query(noteable_fields)
+    <<~QRY
+      {
+        project(fullPath: "#{noteable.project.full_path}") {
+          issue(iid: "#{noteable.iid}") {
+            #{noteable_fields}
+          }
+        }
+      }
+    QRY
+  end
+
+  it_behaves_like 'exposing regular notes on a noteable in GraphQL'
+end
diff --git a/spec/requests/api/graphql/project/merge_request/diff_notes_spec.rb b/spec/requests/api/graphql/project/merge_request/diff_notes_spec.rb
new file mode 100644
index 00000000000..e260e4463f4
--- /dev/null
+++ b/spec/requests/api/graphql/project/merge_request/diff_notes_spec.rb
@@ -0,0 +1,90 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'getting notes for a merge request' do
+  include GraphqlHelpers
+
+  let(:noteable) { create(:merge_request) }
+
+  def noteable_query(noteable_fields)
+    <<~QRY
+      {
+        project(fullPath: "#{noteable.project.full_path}") {
+          id
+          mergeRequest(iid: "#{noteable.iid}") {
+            #{noteable_fields}
+          }
+        }
+      }
+    QRY
+  end
+  let(:noteable_data) { graphql_data['project']['mergeRequest'] }
+
+  it_behaves_like "exposing regular notes on a noteable in GraphQL"
+
+  context 'diff notes on a merge request' do
+    let(:project) { noteable.project }
+    let!(:note) { create(:diff_note_on_merge_request, noteable: noteable, project: project) }
+    let(:user) { note.author }
+
+    let(:query) do
+      noteable_query(
+        <<~NOTES
+        notes {
+          edges {
+            node {
+              #{all_graphql_fields_for('Note')}
+            }
+          }
+        }
+      NOTES
+      )
+    end
+
+    it_behaves_like 'a working graphql query' do
+      before do
+        post_graphql(query, current_user: user)
+      end
+    end
+
+    it 'includes the note' do
+      post_graphql(query, current_user: user)
+
+      expect(graphql_data['project']['mergeRequest']['notes']['edges'].last['node']['body'])
+        .to eq(note.note)
+    end
+
+    context 'the position of the diffnote' do
+      it 'includes a correct position' do
+        post_graphql(query, current_user: user)
+
+        note_data = noteable_data['notes']['edges'].last['node']
+
+        expect(note_data['position']['positionType']).to eq('text')
+        expect(note_data['position']['newLine']).to be_present
+        expect(note_data['position']['x']).not_to be_present
+        expect(note_data['position']['y']).not_to be_present
+        expect(note_data['position']['width']).not_to be_present
+        expect(note_data['position']['height']).not_to be_present
+      end
+
+      context 'with a note on an image' do
+        let(:note) { create(:image_diff_note_on_merge_request, noteable: noteable, project: project) }
+
+        it 'includes a correct position' do
+          post_graphql(query, current_user: user)
+
+          note_data = noteable_data['notes']['edges'].last['node']
+
+          expect(note_data['position']['positionType']).to eq('image')
+          expect(note_data['position']['x']).to be_present
+          expect(note_data['position']['y']).to be_present
+          expect(note_data['position']['width']).to be_present
+          expect(note_data['position']['height']).to be_present
+          expect(note_data['position']['newLine']).not_to be_present
+        end
+      end
+    end
+  end
+end