Display slash commands outcome when previewing Markdown

Remove slash commands from Markdown preview and display their outcome next to
the text field.
Introduce new "explanation" block to our slash commands DSL.
Introduce optional "parse_params" block to slash commands DSL that allows to
process a parameter before it is passed to "explanation" or "command" blocks.
Pass path for previewing Markdown as "data" attribute instead of setting
a variable on "window".

1 files changed, 207 insertions, 0 deletions

diff --git a/spec/services/slash_commands/interpret_service_spec.rb b/spec/services/slash_commands/interpret_service_spec.rb
index 29e65fe7ce6..46cfac4a128 100644
--- a/spec/services/slash_commands/interpret_service_spec.rb
+++ b/spec/services/slash_commands/interpret_service_spec.rb
@@ -798,4 +798,211 @@ describe SlashCommands::InterpretService, services: true do
       end
     end
   end
+
+  describe '#explain' do
+    let(:service) { described_class.new(project, developer) }
+    let(:merge_request) { create(:merge_request, source_project: project) }
+
+    describe 'close command' do
+      let(:content) { '/close' }
+
+      it 'includes issuable name' do
+        _, explanations = service.explain(content, issue)
+
+        expect(explanations).to eq(['Closes this issue.'])
+      end
+    end
+
+    describe 'reopen command' do
+      let(:content) { '/reopen' }
+      let(:merge_request) { create(:merge_request, :closed, source_project: project) }
+
+      it 'includes issuable name' do
+        _, explanations = service.explain(content, merge_request)
+
+        expect(explanations).to eq(['Reopens this merge request.'])
+      end
+    end
+
+    describe 'title command' do
+      let(:content) { '/title This is new title' }
+
+      it 'includes new title' do
+        _, explanations = service.explain(content, issue)
+
+        expect(explanations).to eq(['Changes the title to "This is new title".'])
+      end
+    end
+
+    describe 'assign command' do
+      let(:content) { "/assign @#{developer.username} do it!" }
+
+      it 'includes only the user reference' do
+        _, explanations = service.explain(content, merge_request)
+
+        expect(explanations).to eq(["Assigns @#{developer.username}."])
+      end
+    end
+
+    describe 'unassign command' do
+      let(:content) { '/unassign' }
+      let(:issue) { create(:issue, project: project, assignee: developer) }
+
+      it 'includes current assignee reference' do
+        _, explanations = service.explain(content, issue)
+
+        expect(explanations).to eq(["Removes assignee @#{developer.username}."])
+      end
+    end
+
+    describe 'milestone command' do
+      let(:content) { '/milestone %wrong-milestone' }
+      let!(:milestone) { create(:milestone, project: project, title: '9.10') }
+
+      it 'is empty when milestone reference is wrong' do
+        _, explanations = service.explain(content, issue)
+
+        expect(explanations).to eq([])
+      end
+    end
+
+    describe 'remove milestone command' do
+      let(:content) { '/remove_milestone' }
+      let(:merge_request) { create(:merge_request, source_project: project, milestone: milestone) }
+
+      it 'includes current milestone name' do
+        _, explanations = service.explain(content, merge_request)
+
+        expect(explanations).to eq(['Removes %"9.10" milestone.'])
+      end
+    end
+
+    describe 'label command' do
+      let(:content) { '/label ~missing' }
+      let!(:label) { create(:label, project: project) }
+
+      it 'is empty when there are no correct labels' do
+        _, explanations = service.explain(content, issue)
+
+        expect(explanations).to eq([])
+      end
+    end
+
+    describe 'unlabel command' do
+      let(:content) { '/unlabel' }
+
+      it 'says all labels if no parameter provided' do
+        merge_request.update!(label_ids: [bug.id])
+        _, explanations = service.explain(content, merge_request)
+
+        expect(explanations).to eq(['Removes all labels.'])
+      end
+    end
+
+    describe 'relabel command' do
+      let(:content) { '/relabel Bug' }
+      let!(:bug) { create(:label, project: project, title: 'Bug') }
+      let(:feature) { create(:label, project: project, title: 'Feature') }
+
+      it 'includes label name' do
+        issue.update!(label_ids: [feature.id])
+        _, explanations = service.explain(content, issue)
+
+        expect(explanations).to eq(["Replaces all labels with ~#{bug.id} label."])
+      end
+    end
+
+    describe 'subscribe command' do
+      let(:content) { '/subscribe' }
+
+      it 'includes issuable name' do
+        _, explanations = service.explain(content, issue)
+
+        expect(explanations).to eq(['Subscribes to this issue.'])
+      end
+    end
+
+    describe 'unsubscribe command' do
+      let(:content) { '/unsubscribe' }
+
+      it 'includes issuable name' do
+        merge_request.subscribe(developer, project)
+        _, explanations = service.explain(content, merge_request)
+
+        expect(explanations).to eq(['Unsubscribes from this merge request.'])
+      end
+    end
+
+    describe 'due command' do
+      let(:content) { '/due April 1st 2016' }
+
+      it 'includes the date' do
+        _, explanations = service.explain(content, issue)
+
+        expect(explanations).to eq(['Sets the due date to Apr 1, 2016.'])
+      end
+    end
+
+    describe 'wip command' do
+      let(:content) { '/wip' }
+
+      it 'includes the new status' do
+        _, explanations = service.explain(content, merge_request)
+
+        expect(explanations).to eq(['Marks this merge request as Work In Progress.'])
+      end
+    end
+
+    describe 'award command' do
+      let(:content) { '/award :confetti_ball: ' }
+
+      it 'includes the emoji' do
+        _, explanations = service.explain(content, issue)
+
+        expect(explanations).to eq(['Toggles :confetti_ball: emoji award.'])
+      end
+    end
+
+    describe 'estimate command' do
+      let(:content) { '/estimate 79d' }
+
+      it 'includes the formatted duration' do
+        _, explanations = service.explain(content, merge_request)
+
+        expect(explanations).to eq(['Sets time estimate to 3mo 3w 4d.'])
+      end
+    end
+
+    describe 'spend command' do
+      let(:content) { '/spend -120m' }
+
+      it 'includes the formatted duration and proper verb' do
+        _, explanations = service.explain(content, issue)
+
+        expect(explanations).to eq(['Substracts 2h spent time.'])
+      end
+    end
+
+    describe 'target branch command' do
+      let(:content) { '/target_branch my-feature ' }
+
+      it 'includes the branch name' do
+        _, explanations = service.explain(content, merge_request)
+
+        expect(explanations).to eq(['Sets target branch to my-feature.'])
+      end
+    end
+
+    describe 'board move command' do
+      let(:content) { '/board_move ~bug' }
+      let!(:bug) { create(:label, project: project, title: 'bug') }
+      let!(:board) { create(:board, project: project) }
+
+      it 'includes the label name' do
+        _, explanations = service.explain(content, issue)
+
+        expect(explanations).to eq(["Moves issue to ~#{bug.id} column in the board."])
+      end
+    end
+  end
 end