From 93b7360ad5f7ca9ed0d0f8adf266b2cc4d11f441 Mon Sep 17 00:00:00 2001
From: Benedikt Brunner <benedikt.brunner@pickware.de>
Date: Mon, 24 Jun 2024 08:45:37 +0200
Subject: [PATCH] feat: allow Github style merge commits

---
 src/Rule/DisallowRepeatedCommits.php       |  8 ++++
 tests/Rule/DisallowRepeatedCommitsTest.php | 48 ++++++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/src/Rule/DisallowRepeatedCommits.php b/src/Rule/DisallowRepeatedCommits.php
index 1c9b6b58..0fddefb2 100644
--- a/src/Rule/DisallowRepeatedCommits.php
+++ b/src/Rule/DisallowRepeatedCommits.php
@@ -4,6 +4,7 @@
 namespace Danger\Rule;
 
 use Danger\Context;
+use Danger\Platform\Github\Github;
 
 class DisallowRepeatedCommits
 {
@@ -15,6 +16,13 @@ public function __invoke(Context $context): void
     {
         $messages = $context->platform->pullRequest->getCommits()->getMessages();
 
+        if ($context->platform instanceof Github) {
+            $messages = array_filter(
+                $messages,
+                fn ($message) => !(preg_match('/^Merge branch .* into .*$/', $message) === 1),
+            );
+        }
+
         if (\count($messages) !== \count(array_unique($messages))) {
             $context->failure($this->message);
         }
diff --git a/tests/Rule/DisallowRepeatedCommitsTest.php b/tests/Rule/DisallowRepeatedCommitsTest.php
index 2a809bac..1701bbbe 100644
--- a/tests/Rule/DisallowRepeatedCommitsTest.php
+++ b/tests/Rule/DisallowRepeatedCommitsTest.php
@@ -57,4 +57,52 @@ public function testRuleNotMatches(): void
 
         static::assertFalse($context->hasFailures());
     }
+
+    public function testRuleMatchesWithMergeCommits(): void
+    {
+        $commit = new Commit();
+        $commit->message = 'Test';
+
+        $secondCommit = new Commit();
+        $secondCommit->message = 'Test';
+
+        $thirdCommit = new Commit();
+        $thirdCommit->message = 'Merge branch master into feature';
+
+        $github = $this->createMock(Github::class);
+        $pr = $this->createMock(PullRequest::class);
+        $pr->method('getCommits')->willReturn(new CommitCollection([$commit, $secondCommit, $thirdCommit]));
+        $github->pullRequest = $pr;
+
+        $context = new Context($github);
+
+        $rule = new DisallowRepeatedCommits();
+        $rule($context);
+
+        static::assertTrue($context->hasFailures());
+    }
+
+    public function testRuleNotMatchesWithMultipleMergeCommits(): void
+    {
+        $commit = new Commit();
+        $commit->message = 'Test';
+
+        $secondCommit = new Commit();
+        $secondCommit->message = 'Merge branch master into features';
+
+        $thirdCommit = new Commit();
+        $thirdCommit->message = 'Merge branch master into feature';
+
+        $github = $this->createMock(Github::class);
+        $pr = $this->createMock(PullRequest::class);
+        $pr->method('getCommits')->willReturn(new CommitCollection([$commit, $secondCommit, $thirdCommit]));
+        $github->pullRequest = $pr;
+
+        $context = new Context($github);
+
+        $rule = new DisallowRepeatedCommits();
+        $rule($context);
+
+        static::assertFalse($context->hasFailures());
+    }
 }