feat: update pr/mr title if needed

lib/modulesync/git_service/github.rb

@@ -41,8 +41,17 @@ def _open_pull_request(repo_path:, namespace:, title:, message:, source_branch:,
                                            base: target_branch,
                                            head: head)
         unless pull_requests.empty?
-          # Skip creating the PR if it exists already.
-          $stdout.puts "Skipped! #{pull_requests.length} PRs found for branch '#{source_branch}'"
+          # assumption: there should only be one PR for a given source and target branch, so we just take the first one
+          pr = pull_requests.first
+
+          if pr['title'] == title
+            $stdout.puts "Skipped! #{pull_requests.length} PRs found for branch '#{source_branch}'"
+            $stdout.puts "Skipped! Existing PR ##{pr['number']} already has title '#{title}'"
+          else
+            @api.update_pull_request(repo_path, pr['number'], title: title)
+            $stdout.puts "Updated title of existing PR ##{pr['number']} to '#{title}'"
+          end
+
           return
         end
 

lib/modulesync/git_service/gitlab.rb

@@ -40,8 +40,17 @@ def _open_pull_request(repo_path:, namespace:, title:, message:, source_branch:,
                                              source_branch: source_branch,
                                              target_branch: target_branch)
         unless merge_requests.empty?
-          # Skip creating the MR if it exists already.
-          $stdout.puts "Skipped! #{merge_requests.length} MRs found for branch '#{source_branch}'"
+          # assumption: there should only be one MR for a given source and target branch, so we just take the first one
+          mr = merge_requests.first
+
+          if mr['title'] == title
+            $stdout.puts "Skipped! #{merge_requests.length} MRs found for branch '#{source_branch}'"
+            $stdout.puts "Skipped! Existing MR !#{mr['iid']} already has title '#{title}'"
+          else
+            @api.update_merge_request(repo_path, mr['iid'], title: title)
+            $stdout.puts "Updated title of existing MR !#{mr['iid']} to '#{title}'"
+          end
+
           return
         end
 

spec/unit/module_sync/git_service/github_spec.rb

@@ -54,7 +54,7 @@
       expect { @it.open_pull_request(**args) }.to output(/Submitted PR/).to_stdout
     end
 
-    it 'skips submitting PR if one has already been issued' do
+    it 'updates the title if an existing PR has a different title' do
       pr = {
         'title' => 'Test title',
         'html_url' => 'https://example.com/pulls/44',
@@ -66,7 +66,28 @@
               state: 'open',
               base: 'master',
               head: "#{args[:namespace]}:#{args[:source_branch]}").and_return([pr])
-      expect { @it.open_pull_request(**args) }.to output("Skipped! 1 PRs found for branch 'test'\n").to_stdout
+      expect(@client).to receive(:update_pull_request)
+        .with(args[:repo_path], pr['number'], title: args[:title])
+      expect { @it.open_pull_request(**args) }
+        .to output("Updated title of existing PR #44 to 'Test PR is submitted'\n").to_stdout
+    end
+
+    it 'skips updating an existing PR if its title is unchanged' do
+      pr = {
+        'title' => args[:title],
+        'html_url' => 'https://example.com/pulls/44',
+        'number' => '44',
+      }
+
+      expect(@client).to receive(:pull_requests)
+        .with(args[:repo_path],
+              state: 'open',
+              base: 'master',
+              head: "#{args[:namespace]}:#{args[:source_branch]}").and_return([pr])
+      expect(@client).not_to receive(:update_pull_request)
+      expect { @it.open_pull_request(**args) }
+        .to output("Skipped! 1 PRs found for branch 'test'\n" \
+                   "Skipped! Existing PR #44 already has title 'Test PR is submitted'\n").to_stdout
     end
 
     context 'when labels are set' do

spec/unit/module_sync/git_service/gitlab_spec.rb

@@ -44,7 +44,7 @@
       expect { @it.open_pull_request(**args) }.to output(/Submitted MR/).to_stdout
     end
 
-    it 'skips submitting MR if one has already been issued' do
+    it 'updates the title if an existing MR has a different title' do
       mr = {
         'title' => 'Test title',
         'html_url' => 'https://example.com/pulls/44',
@@ -56,8 +56,28 @@
               state: 'opened',
               source_branch: args[:source_branch],
               target_branch: 'master').and_return([mr])
+      expect(@client).to receive(:update_merge_request)
+        .with(args[:repo_path], mr['iid'], title: args[:title])
+      expect { @it.open_pull_request(**args) }
+        .to output("Updated title of existing MR !44 to 'Test MR is submitted'\n").to_stdout
+    end
+
+    it 'skips updating an existing MR if its title is unchanged' do
+      mr = {
+        'title' => args[:title],
+        'html_url' => 'https://example.com/pulls/44',
+        'iid' => '44',
+      }
 
-      expect { @it.open_pull_request(**args) }.to output("Skipped! 1 MRs found for branch 'test'\n").to_stdout
+      expect(@client).to receive(:merge_requests)
+        .with(args[:repo_path],
+              state: 'opened',
+              source_branch: args[:source_branch],
+              target_branch: 'master').and_return([mr])
+      expect(@client).not_to receive(:update_merge_request)
+      expect { @it.open_pull_request(**args) }
+        .to output("Skipped! 1 MRs found for branch 'test'\n" \
+                   "Skipped! Existing MR !44 already has title 'Test MR is submitted'\n").to_stdout
     end
 
     context 'when labels are set' do