Add remove-source-branch option to pull-request:merge command

Author: phansys

src/Command/PullRequest/PullRequestMergeCommand.php

@@ -42,6 +42,7 @@ protected function configure()
             ->addOption('force-squash', null, InputOption::VALUE_NONE, 'Force squashing the PR, even if there are multiple authors (this will implicitly use --squash)')
             ->addOption('switch', null, InputOption::VALUE_REQUIRED, 'Switch the base of the pull request before merging')
             ->addOption('pat', null, InputOption::VALUE_REQUIRED, 'Give the PR\'s author a pat on the back after the merge')
+            ->addOption('remove-source-branch', null, InputOption::VALUE_NONE, 'Remove remote source branch after merging own pull request')
             ->setHelp(
                 <<<'EOF'
 The <info>%command.name%</info> command merges the given pull request:
@@ -99,6 +100,11 @@ protected function configure()
 which has precedence to the predefined configuration.
 
 <comment>The whole pat configuration will be ignored and no pat will be placed if the pull request is authored by yourself!</comment>
+
+If you are the author of the pull request, <comment>--remove-source-branch</comment> can be used in order to remove the remote source
+branch after a successful merge:
+
+    <info>$ gush %command.name% --remove-source-branch</info>
 EOF
             )
         ;
@@ -141,6 +147,12 @@ protected function execute(InputInterface $input, OutputInterface $output)
             $targetLabel = sprintf('Target: %s/%s', $targetRemote, $targetBranch);
         }
 
+        $authenticatedUser = $this->getParameter($input, 'authentication')['username'];
+        $removeSourceBranch = $input->getOption('remove-source-branch');
+        if ($removeSourceBranch && $pr['user'] !== $authenticatedUser) {
+            throw new UserException(sprintf('`--remove-source-branch` option cannot be used with pull requests that aren\'t owned by the authenticated user (%s)', $authenticatedUser));
+        }
+
         $styleHelper->title(sprintf('Merging pull-request #%d - %s', $prNumber, $pr['title']));
         $styleHelper->text([sprintf('Source: %s/%s', $sourceRemote, $sourceBranch), $targetLabel]);
 
@@ -197,11 +209,13 @@ protected function execute(InputInterface $input, OutputInterface $output)
                 $this->addClosedPullRequestNote($pr, $mergeCommit, $squash, $input->getOption('switch'));
             }
 
-            if ($pr['user'] !== $this->getParameter($input, 'authentication')['username']) {
-                $patComment = $this->givePatToPullRequestAuthor($pr, $input->getOption('pat'));
-                if ($patComment) {
-                    $styleHelper->note(sprintf('Pat given to @%s at %s.', $pr['user'], $patComment));
+            if ($pr['user'] === $authenticatedUser) {
+                if ($removeSourceBranch) {
+                    $adapter->removePullRequestSourceBranch($pr['number']);
+                    $styleHelper->note(sprintf('Remote source branch %s:%s has been removed.', $sourceRemote, $sourceBranch));
                 }
+            } elseif ($patComment = $this->givePatToPullRequestAuthor($pr, $input->getOption('pat'))) {
+                $styleHelper->note(sprintf('Pat given to @%s at %s.', $pr['user'], $patComment));
             }
 
             $styleHelper->success([$mergeNote, $pr['url']]);

src/ThirdParty/Github/GitHubAdapter.php

@@ -625,6 +625,14 @@ public function createReleaseAssets($id, $name, $contentType, $content)
         return $asset['id'];
     }
 
+    public function removePullRequestSourceBranch($id)
+    {
+        $api = $this->client->api('git_data')->references();
+        $pr = $this->getPullRequest($id);
+
+        return $api->remove($pr['user'], $pr['head']['repo'], 'heads/'.$pr['head']['ref']);
+    }
+
     protected function adaptIssueStructure(array $issue)
     {
         return [