Simplify internal post receive messages

Instead of sending varied data to Gitaly, and making Gitaly construct
various messages, build the messages first and have Gitaly print
either basic messages or alert messages, in the order they come.

Depends on https://gitlab.com/gitlab-org/gitaly/merge_requests/1410

2 files changed, 161 insertions, 24 deletions

diff --git a/spec/lib/gitlab/internal_post_receive/response_spec.rb b/spec/lib/gitlab/internal_post_receive/response_spec.rb
new file mode 100644
index 00000000000..f43762c9248
--- /dev/null
+++ b/spec/lib/gitlab/internal_post_receive/response_spec.rb
@@ -0,0 +1,121 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::InternalPostReceive::Response do
+  subject { described_class.new }
+
+  describe '#add_merge_request_urls' do
+    context 'when there are urls_data' do
+      it 'adds a message for each merge request URL' do
+        urls_data = [
+          { new_merge_request: false, branch_name: 'foo', url: 'http://example.com/foo/bar/merge_requests/1' },
+          { new_merge_request: true, branch_name: 'bar', url: 'http://example.com/foo/bar/merge_requests/new?merge_request%5Bsource_branch%5D=bar' }
+        ]
+
+        subject.add_merge_request_urls(urls_data)
+
+        expected = [a_kind_of(described_class::Message), a_kind_of(described_class::Message)]
+        expect(subject.messages).to match(expected)
+      end
+    end
+  end
+
+  describe '#add_merge_request_url' do
+    context 'when :new_merge_request is false' do
+      it 'adds a basic message to view the existing merge request' do
+        url_data = { new_merge_request: false, branch_name: 'foo', url: 'http://example.com/foo/bar/merge_requests/1' }
+
+        subject.add_merge_request_url(url_data)
+
+        message = <<~MESSAGE.strip
+          View merge request for foo:
+            http://example.com/foo/bar/merge_requests/1
+        MESSAGE
+
+        expect(subject.messages.first.message).to eq(message)
+        expect(subject.messages.first.type).to eq(:basic)
+      end
+    end
+
+    context 'when :new_merge_request is true' do
+      it 'adds a basic message to create a new merge request' do
+        url_data = { new_merge_request: true, branch_name: 'bar', url: 'http://example.com/foo/bar/merge_requests/new?merge_request%5Bsource_branch%5D=bar' }
+
+        subject.add_merge_request_url(url_data)
+
+        message = <<~MESSAGE.strip
+          To create a merge request for bar, visit:
+            http://example.com/foo/bar/merge_requests/new?merge_request%5Bsource_branch%5D=bar
+        MESSAGE
+
+        expect(subject.messages.first.message).to eq(message)
+        expect(subject.messages.first.type).to eq(:basic)
+      end
+    end
+  end
+
+  describe '#add_basic_message' do
+    context 'when text is present' do
+      it 'adds a basic message' do
+        subject.add_basic_message('hello')
+
+        expect(subject.messages.first.message).to eq('hello')
+        expect(subject.messages.first.type).to eq(:basic)
+      end
+    end
+
+    context 'when text is blank' do
+      it 'does not add a message' do
+        subject.add_basic_message(' ')
+
+        expect(subject.messages).to be_blank
+      end
+    end
+  end
+
+  describe '#add_alert_message' do
+    context 'when text is present' do
+      it 'adds a alert message' do
+        subject.add_alert_message('hello')
+
+        expect(subject.messages.first.message).to eq('hello')
+        expect(subject.messages.first.type).to eq(:alert)
+      end
+    end
+
+    context 'when text is blank' do
+      it 'does not add a message' do
+        subject.add_alert_message(' ')
+
+        expect(subject.messages).to be_blank
+      end
+    end
+  end
+
+  describe '#reference_counter_decreased' do
+    context 'initially' do
+      it 'reference_counter_decreased is set to false' do
+        expect(subject.reference_counter_decreased).to eq(false)
+      end
+    end
+  end
+
+  describe '#reference_counter_decreased=' do
+    context 'when the argument is truthy' do
+      it 'reference_counter_decreased is truthy' do
+        subject.reference_counter_decreased = true
+
+        expect(subject.reference_counter_decreased).to be_truthy
+      end
+    end
+
+    context 'when the argument is falsey' do
+      it 'reference_counter_decreased is falsey' do
+        subject.reference_counter_decreased = false
+
+        expect(subject.reference_counter_decreased).to be_falsey
+      end
+    end
+  end
+end
diff --git a/spec/requests/api/internal_spec.rb b/spec/requests/api/internal_spec.rb
index 3ab1818bebb..c94f6d22e74 100644
--- a/spec/requests/api/internal_spec.rb
+++ b/spec/requests/api/internal_spec.rb
@@ -925,19 +925,20 @@ describe API::Internal do
     it 'returns link to create new merge request' do
       post api('/internal/post_receive'), params: valid_params
 
-      expect(json_response['merge_request_urls']).to match [{
-        "branch_name" => branch_name,
-        "url" => "http://#{Gitlab.config.gitlab.host}/#{project.full_path}/merge_requests/new?merge_request%5Bsource_branch%5D=#{branch_name}",
-        "new_merge_request" => true
-      }]
+      message = <<~MESSAGE.strip
+        To create a merge request for #{branch_name}, visit:
+          http://#{Gitlab.config.gitlab.host}/#{project.full_path}/merge_requests/new?merge_request%5Bsource_branch%5D=#{branch_name}
+      MESSAGE
+
+      expect(json_response['messages']).to include(build_basic_message(message))
     end
 
-    it 'returns empty array if printing_merge_request_link_enabled is false' do
+    it 'returns no merge request messages if printing_merge_request_link_enabled is false' do
       project.update!(printing_merge_request_link_enabled: false)
 
       post api('/internal/post_receive'), params: valid_params
 
-      expect(json_response['merge_request_urls']).to eq([])
+      expect(json_response['messages']).to be_blank
     end
 
     it 'does not invoke MergeRequests::PushOptionsHandlerService' do
@@ -968,11 +969,12 @@ describe API::Internal do
       it 'links to the newly created merge request' do
         post api('/internal/post_receive'), params: valid_params
 
-        expect(json_response['merge_request_urls']).to match [{
-          'branch_name' => branch_name,
-          'url' => "http://#{Gitlab.config.gitlab.host}/#{project.full_path}/merge_requests/1",
-          'new_merge_request' => false
-        }]
+        message = <<~MESSAGE.strip
+          View merge request for #{branch_name}:
+            http://#{Gitlab.config.gitlab.host}/#{project.full_path}/merge_requests/1
+        MESSAGE
+
+        expect(json_response['messages']).to include(build_basic_message(message))
       end
 
       it 'adds errors on the service instance to warnings' do
@@ -982,7 +984,8 @@ describe API::Internal do
 
         post api('/internal/post_receive'), params: valid_params
 
-        expect(json_response['warnings']).to eq('Error encountered with push options \'merge_request.create\': my error')
+        message = "WARNINGS:\nError encountered with push options 'merge_request.create': my error"
+        expect(json_response['messages']).to include(build_alert_message(message))
       end
 
       it 'adds ActiveRecord errors on invalid MergeRequest records to warnings' do
@@ -995,38 +998,39 @@ describe API::Internal do
 
         post api('/internal/post_receive'), params: valid_params
 
-        expect(json_response['warnings']).to eq('Error encountered with push options \'merge_request.create\': my error')
+        message = "WARNINGS:\nError encountered with push options 'merge_request.create': my error"
+        expect(json_response['messages']).to include(build_alert_message(message))
       end
     end
 
     context 'broadcast message exists' do
       let!(:broadcast_message) { create(:broadcast_message, starts_at: 1.day.ago, ends_at: 1.day.from_now ) }
 
-      it 'returns one broadcast message' do
+      it 'outputs a broadcast message' do
         post api('/internal/post_receive'), params: valid_params
 
         expect(response).to have_gitlab_http_status(200)
-        expect(json_response['broadcast_message']).to eq(broadcast_message.message)
+        expect(json_response['messages']).to include(build_alert_message(broadcast_message.message))
       end
     end
 
     context 'broadcast message does not exist' do
-      it 'returns empty string' do
+      it 'does not output a broadcast message' do
         post api('/internal/post_receive'), params: valid_params
 
         expect(response).to have_gitlab_http_status(200)
-        expect(json_response['broadcast_message']).to eq(nil)
+        expect(has_alert_messages?(json_response['messages'])).to be_falsey
       end
     end
 
     context 'nil broadcast message' do
-      it 'returns empty string' do
+      it 'does not output a broadcast message' do
         allow(BroadcastMessage).to receive(:current).and_return(nil)
 
         post api('/internal/post_receive'), params: valid_params
 
         expect(response).to have_gitlab_http_status(200)
-        expect(json_response['broadcast_message']).to eq(nil)
+        expect(has_alert_messages?(json_response['messages'])).to be_falsey
       end
     end
 
@@ -1038,8 +1042,7 @@ describe API::Internal do
         post api('/internal/post_receive'), params: valid_params
 
         expect(response).to have_gitlab_http_status(200)
-        expect(json_response["redirected_message"]).to be_present
-        expect(json_response["redirected_message"]).to eq(project_moved.message)
+        expect(json_response['messages']).to include(build_basic_message(project_moved.message))
       end
     end
 
@@ -1051,8 +1054,7 @@ describe API::Internal do
         post api('/internal/post_receive'), params: valid_params
 
         expect(response).to have_gitlab_http_status(200)
-        expect(json_response["project_created_message"]).to be_present
-        expect(json_response["project_created_message"]).to eq(project_created.message)
+        expect(json_response['messages']).to include(build_basic_message(project_created.message))
       end
     end
 
@@ -1172,4 +1174,18 @@ describe API::Internal do
       }
     )
   end
+
+  def build_alert_message(message)
+    { 'type' => 'alert', 'message' => message }
+  end
+
+  def build_basic_message(message)
+    { 'type' => 'basic', 'message' => message }
+  end
+
+  def has_alert_messages?(messages)
+    messages.any? do |message|
+      message['type'] == 'alert'
+    end
+  end
 end