diff --git a/src/VCS/Adapter/Git/GitLab.php b/src/VCS/Adapter/Git/GitLab.php
index 988cd3e7..cc0a7407 100644
--- a/src/VCS/Adapter/Git/GitLab.php
+++ b/src/VCS/Adapter/Git/GitLab.php
@@ -99,6 +99,42 @@ private function getNamespaceId(string $owner): string
         return $owner;
     }
 
+    private function findMrIidForNote(string $projectPath, string $commentId): ?int
+    {
+        $page = 1;
+        while (true) {
+            $url = "/projects/{$projectPath}/merge_requests?state=all&per_page=100&page={$page}";
+            $response = $this->call(self::METHOD_GET, $url, ['PRIVATE-TOKEN' => $this->accessToken]);
+            $responseHeaders = $response['headers'] ?? [];
+            $statusCode = $responseHeaders['status-code'] ?? 0;
+            if ($statusCode >= 400) {
+                throw new Exception("Failed to list merge requests: HTTP {$statusCode}");
+            }
+            
+            $mrs = $response['body'] ?? [];
+            
+            if (empty($mrs) || !is_array($mrs)) {
+                break;
+            }
+
+            foreach ($mrs as $mr) {
+                $mrIid = $mr['iid'] ?? 0;
+                $noteUrl = "/projects/{$projectPath}/merge_requests/{$mrIid}/notes/{$commentId}";
+                $noteResponse = $this->call(self::METHOD_GET, $noteUrl, ['PRIVATE-TOKEN' => $this->accessToken]);
+                if (($noteResponse['headers']['status-code'] ?? 0) === 200) {
+                    return $mrIid;
+                }
+            }
+
+            if (count($mrs) < 100) {
+                break;
+            }
+            $page++;
+        }
+
+        return null;
+    }
+
     public function createRepository(string $owner, string $repositoryName, bool $private): array
     {
         $namespaceId = (int) $this->getNamespaceId($owner);
@@ -465,22 +501,81 @@ public function createWebhook(string $owner, string $repositoryName, string $url
 
     public function createComment(string $owner, string $repositoryName, int $pullRequestNumber, string $comment): string
     {
-        throw new Exception("Not implemented");
+        $ownerPath = $this->getOwnerPath($owner);
+        $projectPath = urlencode("{$ownerPath}/{$repositoryName}");
+        $url = "/projects/{$projectPath}/merge_requests/{$pullRequestNumber}/notes";
+
+        $response = $this->call(self::METHOD_POST, $url, ['PRIVATE-TOKEN' => $this->accessToken], ['body' => $comment]);
+
+        $responseHeaders = $response['headers'] ?? [];
+        $statusCode = $responseHeaders['status-code'] ?? 0;
+        if ($statusCode >= 400) {
+            throw new Exception("Failed to create comment: HTTP {$statusCode}");
+        }
+
+        $responseBody = $response['body'] ?? [];
+        if (!array_key_exists('id', $responseBody)) {
+            throw new Exception("Comment creation response is missing comment ID.");
+        }
+
+        return (string) ($responseBody['id'] ?? '');
     }
 
     public function getComment(string $owner, string $repositoryName, string $commentId): string
     {
-        throw new Exception("Not implemented");
+        $ownerPath = $this->getOwnerPath($owner);
+        $projectPath = urlencode("{$ownerPath}/{$repositoryName}");
+
+        $mrIid = $this->findMrIidForNote($projectPath, $commentId);
+        if ($mrIid === null) {
+            return '';
+        }
+
+        $noteUrl = "/projects/{$projectPath}/merge_requests/{$mrIid}/notes/{$commentId}";
+        $noteResponse = $this->call(self::METHOD_GET, $noteUrl, ['PRIVATE-TOKEN' => $this->accessToken]);
+        return $noteResponse['body']['body'] ?? '';
     }
 
     public function updateComment(string $owner, string $repositoryName, int $commentId, string $comment): string
     {
-        throw new Exception("Not implemented");
+        $ownerPath = $this->getOwnerPath($owner);
+        $projectPath = urlencode("{$ownerPath}/{$repositoryName}");
+
+        $mrIid = $this->findMrIidForNote($projectPath, (string) $commentId);
+        if ($mrIid === null) {
+            throw new Exception("Failed to update comment: comment ID {$commentId} not found in any merge request.");
+        }
+
+        $noteUrl = "/projects/{$projectPath}/merge_requests/{$mrIid}/notes/{$commentId}";
+        $noteResponse = $this->call(self::METHOD_PUT, $noteUrl, ['PRIVATE-TOKEN' => $this->accessToken], ['body' => $comment]);
+        $noteHeaders = $noteResponse['headers'] ?? [];
+        if (($noteHeaders['status-code'] ?? 0) !== 200) {
+            throw new Exception("Failed to update comment: HTTP " . ($noteHeaders['status-code'] ?? 0));
+        }
+
+        return (string) $commentId;
     }
 
     public function getUser(string $username): array
     {
-        throw new Exception("Not implemented");
+        $url = "/users?username=" . rawurlencode($username);
+
+        $response = $this->call(self::METHOD_GET, $url, ['PRIVATE-TOKEN' => $this->accessToken]);
+
+        $responseHeaders = $response['headers'] ?? [];
+        $statusCode = $responseHeaders['status-code'] ?? 0;
+        if ($statusCode >= 400) {
+            throw new Exception("Failed to get user: HTTP {$statusCode}");
+        }
+
+        $body = $response['body'] ?? [];
+
+        // GitLab returns an array of users — return first match
+        if (empty($body[0])) {
+            throw new Exception("User not found: {$username}");
+        }
+
+        return $body[0];
     }
 
     public function getOwnerName(string $installationId, ?int $repositoryId = null): string
@@ -511,17 +606,123 @@ public function getOwnerName(string $installationId, ?int $repositoryId = null):
 
     public function getPullRequest(string $owner, string $repositoryName, int $pullRequestNumber): array
     {
-        throw new Exception("Not implemented");
+        $ownerPath = $this->getOwnerPath($owner);
+        $projectPath = urlencode("{$ownerPath}/{$repositoryName}");
+        $url = "/projects/{$projectPath}/merge_requests/{$pullRequestNumber}";
+
+        $response = $this->call(self::METHOD_GET, $url, ['PRIVATE-TOKEN' => $this->accessToken]);
+
+        $responseHeaders = $response['headers'] ?? [];
+        $statusCode = $responseHeaders['status-code'] ?? 0;
+        if ($statusCode >= 400) {
+            throw new Exception("Failed to get merge request: HTTP {$statusCode}");
+        }
+
+        $mr = $response['body'] ?? [];
+
+        // Normalize to match expected shape (consistent with Gitea/GitHub)
+        return [
+            'number'  => $mr['iid'] ?? 0,
+            'title'   => $mr['title'] ?? '',
+            'state'   => $mr['state'] ?? '',
+            'head'    => [
+                'ref' => $mr['source_branch'] ?? '',
+                'sha' => $mr['sha'] ?? '',
+            ],
+            'base'    => [
+                'ref' => $mr['target_branch'] ?? '',
+            ],
+        ];
     }
 
     public function getPullRequestFiles(string $owner, string $repositoryName, int $pullRequestNumber): array
     {
-        throw new Exception("Not implemented");
+        $ownerPath = $this->getOwnerPath($owner);
+        $projectPath = urlencode("{$ownerPath}/{$repositoryName}");
+
+        // Poll until diff is ready (patch_id_sha not null)
+        $maxAttempts = 10;
+        for ($attempt = 0; $attempt < $maxAttempts; $attempt++) {
+            $mrResponse = $this->call(
+                self::METHOD_GET,
+                "/projects/{$projectPath}/merge_requests/{$pullRequestNumber}",
+                ['PRIVATE-TOKEN' => $this->accessToken]
+            );
+            $mrBody = $mrResponse['body'] ?? [];
+            if (($mrBody['patch_id_sha'] ?? null) !== null) {
+                break;
+            }
+            usleep(1000000); // 1 second
+        }
+
+        // Fetch diffs with pagination
+        $allFiles = [];
+        $page = 1;
+        $perPage = 100;
+
+        while (true) {
+            $url = "/projects/{$projectPath}/merge_requests/{$pullRequestNumber}/diffs?page={$page}&per_page={$perPage}";
+            $response = $this->call(self::METHOD_GET, $url, ['PRIVATE-TOKEN' => $this->accessToken]);
+
+            $responseHeaders = $response['headers'] ?? [];
+            $statusCode = $responseHeaders['status-code'] ?? 0;
+            if ($statusCode >= 400) {
+                throw new Exception("Failed to get merge request files: HTTP {$statusCode}");
+            }
+
+            $files = $response['body'] ?? [];
+            if (!is_array($files) || empty($files)) {
+                break;
+            }
+
+            foreach ($files as $diff) {
+                $allFiles[] = [
+                    'filename' => $diff['new_path'] ?? $diff['old_path'] ?? '',
+                ];
+            }
+
+            if (count($files) < $perPage) {
+                break;
+            }
+            $page++;
+        }
+
+        return $allFiles;
     }
 
     public function getPullRequestFromBranch(string $owner, string $repositoryName, string $branch): array
     {
-        throw new Exception("Not implemented");
+        $ownerPath = $this->getOwnerPath($owner);
+        $projectPath = urlencode("{$ownerPath}/{$repositoryName}");
+        $url = "/projects/{$projectPath}/merge_requests?state=opened&source_branch=" . urlencode($branch);
+
+        $response = $this->call(self::METHOD_GET, $url, ['PRIVATE-TOKEN' => $this->accessToken]);
+
+        $responseHeaders = $response['headers'] ?? [];
+        $statusCode = $responseHeaders['status-code'] ?? 0;
+        if ($statusCode >= 400) {
+            throw new Exception("Failed to list merge requests: HTTP {$statusCode}");
+        }
+
+        $body = $response['body'] ?? [];
+        if (empty($body[0])) {
+            return [];
+        }
+
+        $mr = $body[0];
+
+        return [
+            'number' => $mr['iid'] ?? 0,
+            'title'  => $mr['title'] ?? '',
+            'state'  => $mr['state'] ?? '',
+            'head'   => [
+                'ref' => $mr['source_branch'] ?? '',
+                'sha' => $mr['sha'] ?? '',
+            ],
+            'base'   => [
+                'ref' => $mr['target_branch'] ?? '',
+            ],
+        ];
     }
 
     public function listBranches(string $owner, string $repositoryName): array
@@ -704,14 +905,24 @@ public function generateCloneCommand(string $owner, string $repositoryName, stri
     public function getEvent(string $event, string $payload): array
     {
         $payloadArray = json_decode($payload, true);
-        if ($payloadArray === false || $payloadArray === null) {
+        if ($payloadArray === null || !is_array($payloadArray)) {
             return [];
         }
 
         switch ($event) {
             case 'Push Hook':
                 $commits = $payloadArray['commits'] ?? [];
-                $latestCommit = !empty($commits) ? $commits[0] : [];
+                $checkoutSha = $payloadArray['checkout_sha'] ?? '';
+                $latestCommit = [];
+                foreach ($commits as $c) {
+                    if (($c['id'] ?? '') === $checkoutSha) {
+                        $latestCommit = $c;
+                        break;
+                    }
+                }
+                if (empty($latestCommit) && !empty($commits)) {
+                    $latestCommit = $commits[0];
+                }
                 $ref = $payloadArray['ref'] ?? '';
                 // ref format: refs/heads/main
                 $branch = str_replace('refs/heads/', '', $ref);
diff --git a/tests/VCS/Adapter/GitLabTest.php b/tests/VCS/Adapter/GitLabTest.php
index fa4600ff..8da97e59 100644
--- a/tests/VCS/Adapter/GitLabTest.php
+++ b/tests/VCS/Adapter/GitLabTest.php
@@ -130,7 +130,31 @@ public function testGetDeletedRepositoryFails(): void
 
     public function testGetPullRequestFromBranch(): void
     {
-        $this->markTestSkipped('Not implemented for GitLab yet');
+        $repositoryName = 'test-get-pr-from-branch-' . \uniqid();
+        $this->vcsAdapter->createRepository(static::$owner, $repositoryName, false);
+
+        try {
+            $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'README.md', '# Test');
+            $this->vcsAdapter->createBranch(static::$owner, $repositoryName, 'my-feature', static::$defaultBranch);
+            $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'feature.txt', 'content', 'Add feature', 'my-feature');
+
+            $this->vcsAdapter->createPullRequest(
+                static::$owner,
+                $repositoryName,
+                'Feature MR',
+                'my-feature',
+                static::$defaultBranch
+            );
+
+            $result = $this->vcsAdapter->getPullRequestFromBranch(static::$owner, $repositoryName, 'my-feature');
+
+            $this->assertIsArray($result);
+            $this->assertNotEmpty($result);
+            $this->assertArrayHasKey('head', $result);
+            $this->assertSame('my-feature', $result['head']['ref'] ?? '');
+        } finally {
+            $this->vcsAdapter->deleteRepository(static::$owner, $repositoryName);
+        }
     }
 
     public function testGetOwnerName(): void
@@ -204,12 +228,70 @@ public function testSearchRepositoriesWithSearch(): void
 
     public function testCreateComment(): void
     {
-        $this->markTestSkipped('Not implemented for GitLab yet');
+        $repositoryName = 'test-create-comment-' . \uniqid();
+        $this->vcsAdapter->createRepository(static::$owner, $repositoryName, false);
+
+        try {
+            $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'README.md', '# Test');
+            $this->vcsAdapter->createBranch(static::$owner, $repositoryName, 'test-branch', static::$defaultBranch);
+            $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'test.txt', 'test', 'Add test', 'test-branch');
+
+            $pr = $this->vcsAdapter->createPullRequest(
+                static::$owner,
+                $repositoryName,
+                'Test PR',
+                'test-branch',
+                static::$defaultBranch
+            );
+
+            $prNumber = $pr['iid'] ?? 0;
+            $this->assertGreaterThan(0, $prNumber);
+
+            $commentId = $this->vcsAdapter->createComment(static::$owner, $repositoryName, $prNumber, 'Test comment');
+
+            $this->assertNotEmpty($commentId);
+            $this->assertIsString($commentId);
+            $this->assertIsNumeric($commentId);
+
+            $retrieved = $this->vcsAdapter->getComment(static::$owner, $repositoryName, $commentId);
+            $this->assertSame('Test comment', $retrieved);
+        } finally {
+            $this->vcsAdapter->deleteRepository(static::$owner, $repositoryName);
+        }
     }
 
     public function testUpdateComment(): void
     {
-        $this->markTestSkipped('Not implemented for GitLab yet');
+        $repositoryName = 'test-update-comment-' . \uniqid();
+        $this->vcsAdapter->createRepository(static::$owner, $repositoryName, false);
+
+        try {
+            $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'README.md', '# Test');
+            $this->vcsAdapter->createBranch(static::$owner, $repositoryName, 'test-branch', static::$defaultBranch);
+            $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'test.txt', 'test', 'Add test', 'test-branch');
+
+            $pr = $this->vcsAdapter->createPullRequest(
+                static::$owner,
+                $repositoryName,
+                'Test PR',
+                'test-branch',
+                static::$defaultBranch
+            );
+
+            $prNumber = $pr['iid'] ?? 0;
+            $this->assertGreaterThan(0, $prNumber);
+
+            $commentId = $this->vcsAdapter->createComment(static::$owner, $repositoryName, $prNumber, 'Original comment');
+
+            $updatedCommentId = $this->vcsAdapter->updateComment(static::$owner, $repositoryName, (int)$commentId, 'Updated comment');
+
+            $this->assertSame($commentId, $updatedCommentId);
+
+            $finalComment = $this->vcsAdapter->getComment(static::$owner, $repositoryName, $commentId);
+            $this->assertSame('Updated comment', $finalComment);
+        } finally {
+            $this->vcsAdapter->deleteRepository(static::$owner, $repositoryName);
+        }
     }
 
     public function testGenerateCloneCommand(): void
@@ -601,7 +683,7 @@ public function testWebhookPullRequestEvent(): void
             }, 15000, 1000);
 
             $this->assertSame('merge_request', $payload['object_kind'] ?? '');
-            $this->assertSame('open', $payload['object_attributes']['action'] ?? '');
+            $this->assertContains($payload['object_attributes']['action'] ?? '', ['open', 'update']);
 
         } finally {
             $this->vcsAdapter->deleteRepository(static::$owner, $repositoryName);
@@ -735,22 +817,118 @@ public function testGetRepositoryNameWithInvalidId(): void
 
     public function testGetComment(): void
     {
-        $this->markTestSkipped('Not implemented for GitLab yet');
+        $repositoryName = 'test-get-comment-' . \uniqid();
+        $this->vcsAdapter->createRepository(static::$owner, $repositoryName, false);
+
+        try {
+            $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'README.md', '# Test');
+            $this->vcsAdapter->createBranch(static::$owner, $repositoryName, 'test-branch', static::$defaultBranch);
+            $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'test.txt', 'test', 'Add test', 'test-branch');
+
+            $pr = $this->vcsAdapter->createPullRequest(
+                static::$owner,
+                $repositoryName,
+                'Test PR',
+                'test-branch',
+                static::$defaultBranch
+            );
+
+            $prNumber = $pr['iid'] ?? 0;
+            $commentId = $this->vcsAdapter->createComment(static::$owner, $repositoryName, $prNumber, 'Test comment');
+
+            $result = $this->vcsAdapter->getComment(static::$owner, $repositoryName, $commentId);
+
+            $this->assertIsString($result);
+            $this->assertSame('Test comment', $result);
+        } finally {
+            $this->vcsAdapter->deleteRepository(static::$owner, $repositoryName);
+        }
     }
 
     public function testGetPullRequest(): void
     {
-        $this->markTestSkipped('Not implemented for GitLab yet');
+        $repositoryName = 'test-get-pull-request-' . \uniqid();
+        $this->vcsAdapter->createRepository(static::$owner, $repositoryName, false);
+
+        try {
+            $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'README.md', '# Test');
+            $this->vcsAdapter->createBranch(static::$owner, $repositoryName, 'feature-branch', static::$defaultBranch);
+            $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'feature.txt', 'feature content', 'Add feature', 'feature-branch');
+
+            $pr = $this->vcsAdapter->createPullRequest(
+                static::$owner,
+                $repositoryName,
+                'Test MR',
+                'feature-branch',
+                static::$defaultBranch,
+                'Test MR description'
+            );
+
+            $prNumber = $pr['iid'] ?? 0;
+            $this->assertGreaterThan(0, $prNumber);
+
+            $result = $this->vcsAdapter->getPullRequest(static::$owner, $repositoryName, $prNumber);
+
+            $this->assertIsArray($result);
+            $this->assertArrayHasKey('number', $result);
+            $this->assertArrayHasKey('title', $result);
+            $this->assertArrayHasKey('state', $result);
+            $this->assertArrayHasKey('head', $result);
+            $this->assertArrayHasKey('base', $result);
+            $this->assertSame($prNumber, $result['number']);
+            $this->assertSame('Test MR', $result['title']);
+            $this->assertSame('opened', $result['state']);
+        } finally {
+            $this->vcsAdapter->deleteRepository(static::$owner, $repositoryName);
+        }
     }
 
     public function testGetPullRequestFiles(): void
     {
-        $this->markTestSkipped('Not implemented for GitLab yet');
+        $repositoryName = 'test-get-pull-request-files-' . \uniqid();
+        $this->vcsAdapter->createRepository(static::$owner, $repositoryName, false);
+
+        try {
+            $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'README.md', '# Test');
+            $this->vcsAdapter->createBranch(static::$owner, $repositoryName, 'feature-branch', static::$defaultBranch);
+            $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'feature.txt', 'feature content', 'Add feature', 'feature-branch');
+
+            $pr = $this->vcsAdapter->createPullRequest(
+                static::$owner,
+                $repositoryName,
+                'Test MR Files',
+                'feature-branch',
+                static::$defaultBranch
+            );
+
+            $prNumber = $pr['iid'] ?? 0;
+            $this->assertGreaterThan(0, $prNumber);
+
+            $result = [];
+            $this->assertEventually(function () use (&$result, $repositoryName, $prNumber) {
+                $result = $this->vcsAdapter->getPullRequestFiles(static::$owner, $repositoryName, $prNumber);
+                $this->assertNotEmpty($result);
+            }, 15000, 1000);
+
+            $this->assertIsArray($result);
+            $filenames = array_column($result, 'filename');
+            $this->assertContains('feature.txt', $filenames);
+        } finally {
+            $this->vcsAdapter->deleteRepository(static::$owner, $repositoryName);
+        }
     }
 
     public function testGetPullRequestWithInvalidNumber(): void
     {
-        $this->markTestSkipped('Not implemented for GitLab yet');
+        $repositoryName = 'test-get-pull-request-invalid-' . \uniqid();
+        $this->vcsAdapter->createRepository(static::$owner, $repositoryName, false);
+
+        try {
+            $this->expectException(\Exception::class);
+            $this->vcsAdapter->getPullRequest(static::$owner, $repositoryName, 99999);
+        } finally {
+            $this->vcsAdapter->deleteRepository(static::$owner, $repositoryName);
+        }
     }
 
     public function testGetRepositoryTree(): void
@@ -884,9 +1062,11 @@ public function testListRepositoryLanguages(): void
             $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'main.php', '<?php echo "test";');
             $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'script.js', 'console.log("test");');
 
-            sleep(5); // ← increase from 2 to 5
-
-            $languages = $this->vcsAdapter->listRepositoryLanguages(static::$owner, $repositoryName);
+            $languages = [];
+            $this->assertEventually(function () use (&$languages, $repositoryName) {
+                $languages = $this->vcsAdapter->listRepositoryLanguages(static::$owner, $repositoryName);
+                $this->assertNotEmpty($languages);
+            }, 30000, 2000);
 
             $this->assertIsArray($languages);
             $this->assertNotEmpty($languages);
@@ -940,4 +1120,178 @@ public function testListRepositoryContents(): void
             $this->vcsAdapter->deleteRepository(static::$owner, $repositoryName);
         }
     }
+
+    public function testGetUser(): void
+    {
+        $result = $this->vcsAdapter->getUser('root');
+
+        $this->assertIsArray($result);
+        $this->assertArrayHasKey('id', $result);
+        $this->assertArrayHasKey('username', $result);
+    }
+
+    public function testGetUserWithInvalidUsername(): void
+    {
+        $this->expectException(\Exception::class);
+        $this->vcsAdapter->getUser('non-existent-user-' . \uniqid());
+    }
+
+    public function testCreatePrivateRepository(): void
+    {
+        $repositoryName = 'test-create-private-repository-' . \uniqid();
+
+        $result = $this->vcsAdapter->createRepository(static::$owner, $repositoryName, true);
+
+        try {
+            $this->assertIsArray($result);
+            $this->assertSame('private', $result['visibility']);
+
+            $fetched = $this->vcsAdapter->getRepository(static::$owner, $repositoryName);
+            $this->assertSame('private', $fetched['visibility']);
+        } finally {
+            $this->vcsAdapter->deleteRepository(static::$owner, $repositoryName);
+        }
+    }
+
+    public function testGetRepositoryWithNonExistingOwner(): void
+    {
+        $repositoryName = 'test-non-existing-owner-' . \uniqid();
+
+        $this->expectException(\Exception::class);
+        $this->vcsAdapter->getRepository('non-existing-owner-' . \uniqid(), $repositoryName);
+    }
+
+    public function testCreateRepositoryWithInvalidName(): void
+    {
+        $repositoryName = 'invalid name with spaces';
+
+        try {
+            $this->vcsAdapter->createRepository(static::$owner, $repositoryName, false);
+            $this->fail('Expected exception for invalid repository name');
+        } catch (\Exception $e) {
+            $this->assertTrue(true);
+        }
+    }
+
+    public function testDeleteRepositoryTwiceFails(): void
+    {
+        $repositoryName = 'test-delete-repository-twice-' . \uniqid();
+        $this->vcsAdapter->createRepository(static::$owner, $repositoryName, false);
+        $this->vcsAdapter->deleteRepository(static::$owner, $repositoryName);
+
+        $this->expectException(\Exception::class);
+        $this->vcsAdapter->deleteRepository(static::$owner, $repositoryName);
+    }
+
+    public function testDeleteNonExistingRepositoryFails(): void
+    {
+        $this->expectException(\Exception::class);
+        $this->vcsAdapter->deleteRepository(static::$owner, 'non-existing-repo-' . \uniqid());
+    }
+
+    public function testGetPullRequestFromBranchNoPR(): void
+    {
+        $repositoryName = 'test-get-pr-no-pr-' . \uniqid();
+        $this->vcsAdapter->createRepository(static::$owner, $repositoryName, false);
+
+        try {
+            $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'README.md', '# Test');
+            $this->vcsAdapter->createBranch(static::$owner, $repositoryName, 'lonely-branch', static::$defaultBranch);
+
+            $result = $this->vcsAdapter->getPullRequestFromBranch(static::$owner, $repositoryName, 'lonely-branch');
+
+            $this->assertIsArray($result);
+            $this->assertEmpty($result);
+        } finally {
+            $this->vcsAdapter->deleteRepository(static::$owner, $repositoryName);
+        }
+    }
+
+    public function testCreateCommentInvalidPR(): void
+    {
+        $repositoryName = 'test-comment-invalid-' . \uniqid();
+        $this->vcsAdapter->createRepository(static::$owner, $repositoryName, false);
+        $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'README.md', '# Test');
+
+        try {
+            $this->expectException(\Exception::class);
+            $this->vcsAdapter->createComment(static::$owner, $repositoryName, 99999, 'Test comment');
+        } finally {
+            $this->vcsAdapter->deleteRepository(static::$owner, $repositoryName);
+        }
+    }
+
+    public function testGetCommentInvalidId(): void
+    {
+        $repositoryName = 'test-get-comment-invalid-' . \uniqid();
+        $this->vcsAdapter->createRepository(static::$owner, $repositoryName, false);
+        $this->vcsAdapter->createFile(static::$owner, $repositoryName, 'README.md', '# Test');
+
+        try {
+            $result = $this->vcsAdapter->getComment(static::$owner, $repositoryName, '99999999');
+
+            $this->assertIsString($result);
+            $this->assertSame('', $result);
+        } finally {
+            $this->vcsAdapter->deleteRepository(static::$owner, $repositoryName);
+        }
+    }
+
+    public function testGetEventPushMatchesCheckoutSha(): void
+    {
+        $payload = json_encode([
+            'object_kind' => 'push',
+            'ref' => 'refs/heads/main',
+            'checkout_sha' => 'def456',
+            'project' => [
+                'name' => 'test-repo',
+                'namespace' => 'test-org',
+            ],
+            'commits' => [
+                [
+                    'id' => 'abc123',
+                    'message' => 'Older commit',
+                    'url' => 'http://example.com/commit/abc123',
+                    'author' => ['name' => 'Old Author'],
+                ],
+                [
+                    'id' => 'def456',
+                    'message' => 'Head commit',
+                    'url' => 'http://example.com/commit/def456',
+                    'author' => ['name' => 'Head Author'],
+                ],
+            ],
+        ]);
+
+        if ($payload === false) {
+            $this->fail('Failed to encode JSON payload');
+        }
+
+        $result = $this->vcsAdapter->getEvent('Push Hook', $payload);
+
+        $this->assertIsArray($result);
+        $this->assertSame('def456', $result['commitHash']);
+        $this->assertSame('Head Author', $result['commitAuthor']);
+        $this->assertSame('Head commit', $result['commitMessage']);
+        $this->assertSame('http://example.com/commit/def456', $result['commitUrl']);
+    }
+
+    public function testValidateWebhookEventUsesPlainToken(): void
+    {
+        $secret = 'my-secret-token';
+        $payload = '{"object_kind":"push"}';
+
+        $this->assertTrue(
+            $this->vcsAdapter->validateWebhookEvent($payload, $secret, $secret)
+        );
+
+        $hmacSignature = hash_hmac('sha256', $payload, $secret);
+        $this->assertFalse(
+            $this->vcsAdapter->validateWebhookEvent($payload, $hmacSignature, $secret)
+        );
+
+        $this->assertFalse(
+            $this->vcsAdapter->validateWebhookEvent($payload, 'wrong-token', $secret)
+        );
+    }
 }