add auto-merge support for GitHub and GitLab merge requests

README.md

@@ -141,6 +141,19 @@ merge_request:
 **It is really useful with `extends` mechanism, f.e. define general template with `variables`
 which will be overriden in child `valhalla.yml`.**
 
+### 🔁 auto-merge
+
+After a successful release valhalla can enable auto-merge on the created MR/PR, so it is merged
+automatically as soon as it gets required approvals and the pipeline passes.
+
+```yml
+merge_request:
+  auto_merge: True
+```
+
+- **GitLab:** configure approval rules, otherwise the MR is merged right after the pipeline succeeds.
+- **GitHub:** enable "Allow auto-merge" in repository settings and branch protection with required reviews.
+
 ### 🐛 environment variables
 
 Valhalla allows you to use any variable defined in your environment system, it is useful f.e when you

test/ci_provider/github/merge_request_test.py

@@ -216,3 +216,107 @@ def test_request_reviewers_failure(self, mock_warn, mock_info, mock_resolve, moc
 
             # then
             mock_warn.assert_any_call("Could not add reviewers: 404 Not found")
+
+    @patch("valhalla.ci_provider.github.merge_request.GitHubClient")
+    @patch("valhalla.ci_provider.github.merge_request.resolve")
+    @patch("valhalla.ci_provider.github.merge_request.info")
+    @patch("valhalla.ci_provider.github.merge_request.warn")
+    def test_enable_auto_merge(self, mock_warn, mock_info, mock_resolve, mock_client_cls):
+        # given
+        with patch.dict('os.environ', {'GITHUB_REF_NAME': 'feature-branch',
+                                       'GITHUB_GRAPHQL_URL': 'https://api.github.com/graphql'}):
+            mock_resolve.side_effect = lambda x: x
+            mock_client = MagicMock()
+            mock_client.api_url = "https://api.github.com"
+            mock_client.repo = "owner/repo"
+
+            pr_response = MagicMock()
+            pr_response.status_code = 201
+            pr_response.json.return_value = {"html_url": "url", "number": 7, "node_id": "PR_node7"}
+
+            graphql_response = MagicMock()
+            graphql_response.status_code = 200
+            graphql_response.json.return_value = {"data": {}}
+
+            mock_client.post.side_effect = [pr_response, graphql_response]
+            mock_client_cls.return_value = mock_client
+
+            pr = GitHubValhallaPullRequest()
+            config = MergeRequestConfig(enabled=True, target_branch="main", title="T", description="D", reviewers=[],
+                                        auto_merge=True)
+
+            # when
+            hook = pr.create(config)
+            hook.enable_auto_merge()
+
+            # then
+            url, kwargs = mock_client.post.call_args[0][0], mock_client.post.call_args[1]
+            self.assertEqual(url, "https://api.github.com/graphql")
+            self.assertIn("enablePullRequestAutoMerge", kwargs['json']['query'])
+            self.assertEqual(kwargs['json']['variables'], {"id": "PR_node7"})
+            mock_warn.assert_not_called()
+
+    @patch("valhalla.ci_provider.github.merge_request.GitHubClient")
+    @patch("valhalla.ci_provider.github.merge_request.resolve")
+    @patch("valhalla.ci_provider.github.merge_request.info")
+    @patch("valhalla.ci_provider.github.merge_request.warn")
+    def test_enable_auto_merge_graphql_error_warns(self, mock_warn, mock_info, mock_resolve, mock_client_cls):
+        # given
+        with patch.dict('os.environ', {'GITHUB_REF_NAME': 'feature-branch'}):
+            mock_resolve.side_effect = lambda x: x
+            mock_client = MagicMock()
+            mock_client.api_url = "https://api.github.com"
+            mock_client.repo = "owner/repo"
+
+            pr_response = MagicMock()
+            pr_response.status_code = 201
+            pr_response.json.return_value = {"html_url": "url", "number": 7, "node_id": "PR_node7"}
+
+            graphql_response = MagicMock()
+            graphql_response.status_code = 200
+            graphql_response.text = "auto-merge is not allowed"
+            graphql_response.json.return_value = {"errors": [{"message": "auto-merge is not allowed"}]}
+
+            mock_client.post.side_effect = [pr_response, graphql_response]
+            mock_client_cls.return_value = mock_client
+
+            pr = GitHubValhallaPullRequest()
+            config = MergeRequestConfig(enabled=True, target_branch="main", title="T", description="D", reviewers=[],
+                                        auto_merge=True)
+
+            # when
+            hook = pr.create(config)
+            hook.enable_auto_merge()
+
+            # then
+            mock_warn.assert_any_call("Could not enable auto-merge for pull request: 200 auto-merge is not allowed")
+
+    @patch("valhalla.ci_provider.github.merge_request.GitHubClient")
+    @patch("valhalla.ci_provider.github.merge_request.resolve")
+    @patch("valhalla.ci_provider.github.merge_request.info")
+    @patch("valhalla.ci_provider.github.merge_request.warn")
+    def test_enable_auto_merge_exception(self, mock_warn, mock_info, mock_resolve, mock_client_cls):
+        # given
+        with patch.dict('os.environ', {'GITHUB_REF_NAME': 'feature-branch'}):
+            mock_resolve.side_effect = lambda x: x
+            mock_client = MagicMock()
+            mock_client.api_url = "https://api.github.com"
+            mock_client.repo = "owner/repo"
+
+            pr_response = MagicMock()
+            pr_response.status_code = 201
+            pr_response.json.return_value = {"html_url": "url", "number": 7, "node_id": "PR_node7"}
+
+            mock_client.post.side_effect = [pr_response, Exception("Network error")]
+            mock_client_cls.return_value = mock_client
+
+            pr = GitHubValhallaPullRequest()
+            config = MergeRequestConfig(enabled=True, target_branch="main", title="T", description="D", reviewers=[],
+                                        auto_merge=True)
+
+            # when
+            hook = pr.create(config)
+            hook.enable_auto_merge()
+
+            # then
+            mock_warn.assert_any_call("Could not enable auto-merge for pull request because: Network error")

test/ci_provider/gitlab/merge_request_test.py

@@ -176,3 +176,91 @@ def test_add_comment_exception(self, mock_warn, mock_info, mock_resolve, mock_ge
 
             # then:
             mock_warn.assert_any_call("Could not add comment to merge request because: GitLab error")
+
+    @patch("valhalla.ci_provider.gitlab.merge_request.get_gitlab_client")
+    @patch("valhalla.ci_provider.gitlab.merge_request.get_project_id")
+    @patch("valhalla.ci_provider.gitlab.merge_request.resolve")
+    @patch("valhalla.ci_provider.gitlab.merge_request.info")
+    @patch("valhalla.ci_provider.gitlab.merge_request.warn")
+    def test_enable_auto_merge(self, mock_warn, mock_info, mock_resolve, mock_get_project_id,
+                               mock_get_gitlab_client):
+        with patch.dict('os.environ', {'CI_COMMIT_BRANCH': 'feature-branch'}):
+            # given:
+            mock_get_project_id.return_value = "123"
+            mock_resolve.side_effect = lambda x: x
+            mock_gitlab_client = MagicMock()
+            mock_project = MagicMock()
+            mock_mr_instance = MagicMock()
+            mock_mr_instance.iid = 101
+            mock_project.mergerequests.create.return_value = mock_mr_instance
+            mock_gitlab_client.projects.get.return_value = mock_project
+            mock_get_gitlab_client.return_value = mock_gitlab_client
+
+            mock_mr_obj = MagicMock()
+            mock_project.mergerequests.get.return_value = mock_mr_obj
+
+            merge_request = GitLabValhallaMergeRequest()
+            config = MergeRequestConfig(enabled=True, target_branch="main", title="T", description="D", reviewers=[],
+                                        auto_merge=True)
+
+            # when:
+            hook = merge_request.create(config)
+            hook.enable_auto_merge()
+
+            # then:
+            mock_mr_obj.merge.assert_called_once_with(merge_when_pipeline_succeeds=True)
+            mock_info.assert_any_call("Auto-merge enabled, merge request will be merged when approvals and pipeline succeed")
+
+    @patch("valhalla.ci_provider.gitlab.merge_request.get_gitlab_client")
+    @patch("valhalla.ci_provider.gitlab.merge_request.get_project_id")
+    @patch("valhalla.ci_provider.gitlab.merge_request.resolve")
+    @patch("valhalla.ci_provider.gitlab.merge_request.info")
+    @patch("valhalla.ci_provider.gitlab.merge_request.warn")
+    def test_enable_auto_merge_exception(self, mock_warn, mock_info, mock_resolve, mock_get_project_id,
+                                         mock_get_gitlab_client):
+        with patch.dict('os.environ', {'CI_COMMIT_BRANCH': 'feature-branch'}):
+            # given:
+            mock_get_project_id.return_value = "123"
+            mock_resolve.side_effect = lambda x: x
+            mock_gitlab_client = MagicMock()
+            mock_project = MagicMock()
+            mock_gitlab_client.projects.get.return_value = mock_project
+            mock_get_gitlab_client.return_value = mock_gitlab_client
+            mock_project.mergerequests.get.return_value.merge.side_effect = Exception("405 Method Not Allowed")
+
+            merge_request = GitLabValhallaMergeRequest()
+            config = MergeRequestConfig(enabled=True, target_branch="main", title="T", description="D", reviewers=[],
+                                        auto_merge=True)
+
+            # when:
+            hook = merge_request.create(config)
+            hook.enable_auto_merge()
+
+            # then:
+            mock_warn.assert_any_call("Could not enable auto-merge for merge request because: 405 Method Not Allowed")
+
+    @patch("valhalla.ci_provider.gitlab.merge_request.get_gitlab_client")
+    @patch("valhalla.ci_provider.gitlab.merge_request.get_project_id")
+    @patch("valhalla.ci_provider.gitlab.merge_request.resolve")
+    @patch("valhalla.ci_provider.gitlab.merge_request.info")
+    @patch("valhalla.ci_provider.gitlab.merge_request.warn")
+    def test_auto_merge_disabled_by_default(self, mock_warn, mock_info, mock_resolve, mock_get_project_id,
+                                            mock_get_gitlab_client):
+        with patch.dict('os.environ', {'CI_COMMIT_BRANCH': 'feature-branch'}):
+            # given:
+            mock_get_project_id.return_value = "123"
+            mock_resolve.side_effect = lambda x: x
+            mock_gitlab_client = MagicMock()
+            mock_project = MagicMock()
+            mock_gitlab_client.projects.get.return_value = mock_project
+            mock_get_gitlab_client.return_value = mock_gitlab_client
+
+            merge_request = GitLabValhallaMergeRequest()
+            config = MergeRequestConfig(enabled=True, target_branch="main", title="T", description="D", reviewers=[])
+
+            # when:
+            hook = merge_request.create(config)
+            hook.enable_auto_merge()
+
+            # then:
+            mock_project.mergerequests.get.return_value.merge.assert_not_called()

test/common/get_config_test.py

@@ -101,6 +101,7 @@ def test_get_config_no_mr_section(self, mock_open_file):
         self.assertEqual(config.merge_request.title, "Releasing version {VERSION} with valhalla!")
         self.assertEqual(config.merge_request.description, "Created by Valhalla! Visit https://github.com/logchange/valhalla and leave a star!")
         self.assertEqual(config.merge_request.reviewers, [])
+        self.assertEqual(config.merge_request.auto_merge, False)
 
         mock_open_file.assert_called_once_with(self.config_path)
 
@@ -121,6 +122,7 @@ def test_get_config_no_mr_section(self, mock_open_file):
         merge_request:
             enabled: False
             title: test mr title
+            auto_merge: True
         """,
     )
     def test_get_config_mr_disabled(self, mock_open_file):
@@ -133,6 +135,7 @@ def test_get_config_mr_disabled(self, mock_open_file):
         self.assertEqual(config.merge_request.title, "test mr title")
         self.assertEqual(config.merge_request.description, "Created by Valhalla! Visit https://github.com/logchange/valhalla and leave a star!")
         self.assertEqual(config.merge_request.reviewers, None)
+        self.assertEqual(config.merge_request.auto_merge, True)
 
         mock_open_file.assert_called_once_with(self.config_path)
 

test/main_start_test.py

@@ -53,6 +53,7 @@ def __init__(self, text):
             self.assertEqual(args[2], "1.2.3")
             # merge request config is default and disabled in our test YAML
             self.assertEqual(mock_create_mr.call_count, 1)
+            mock_create_mr.return_value.enable_auto_merge.assert_called_once()
 
     def test_start_creates_mr_and_posts_error_when_version_empty(self):
         # given: version is empty and from_config does not resolve it (e.g. command failed)
@@ -91,3 +92,4 @@ def __init__(self, text):
                 call_args[0][0] for call_args in provider_hook.add_comment.call_args_list
             )
             self.assertIn("Version to release is empty", posted)
+            provider_hook.enable_auto_merge.assert_not_called()

valhalla/ci_provider/github/merge_request.py

@@ -59,7 +59,21 @@ def _add_comment(comment: str):
             except Exception as e:
                 warn(f"Could not add comment to pull request because: {e}")
 
-        return MergeRequestHook(pr_number, _add_comment)
+        pr_node_id = pr.get('node_id')
+
+        def _enable_auto_merge():
+            try:
+                graphql_url = os.getenv("GITHUB_GRAPHQL_URL", f"{self.client.api_url}/graphql")
+                query = "mutation($id: ID!) { enablePullRequestAutoMerge(input: {pullRequestId: $id}) { clientMutationId } }"
+                resp = self.client.post(graphql_url, json={"query": query, "variables": {"id": pr_node_id}})
+                if resp.status_code >= 300 or resp.json().get('errors'):
+                    warn(f"Could not enable auto-merge for pull request: {resp.status_code} {resp.text}")
+                else:
+                    info("Auto-merge enabled, pull request will be merged when approvals and checks succeed")
+            except Exception as e:
+                warn(f"Could not enable auto-merge for pull request because: {e}")
+
+        return MergeRequestHook(pr_number, _add_comment, _enable_auto_merge if merge_request_config.auto_merge else None)
 
     def __request_reviewers(self, pr_number: int, reviewers):
         try:

valhalla/ci_provider/gitlab/merge_request.py

@@ -51,7 +51,15 @@ def _add_comment(comment: str):
             except Exception as e:
                 warn(f"Could not add comment to merge request because: {e}")
 
-        return MergeRequestHook(mr_iid, _add_comment)
+        def _enable_auto_merge():
+            try:
+                mr_obj = self.project.mergerequests.get(mr_iid, iid=True)
+                mr_obj.merge(merge_when_pipeline_succeeds=True)
+                info("Auto-merge enabled, merge request will be merged when approvals and pipeline succeed")
+            except Exception as e:
+                warn(f"Could not enable auto-merge for merge request because: {e}")
+
+        return MergeRequestHook(mr_iid, _add_comment, _enable_auto_merge if merge_request_config.auto_merge else None)
 
     def __get_reviewer_ids(self, reviewers: List[str]) -> List[int]:
         result = []

valhalla/ci_provider/merge_request_hook.py

@@ -11,19 +11,27 @@ class MergeRequestHook:
 
     - id: identifier of the created MR/PR
     - add_comment: method to add a comment to the created MR/PR
+    - enable_auto_merge: method to let the git host merge the MR/PR once approvals and checks pass
 
     If creation is skipped, use MergeRequestHook.Skip which prints info that MR was not created.
     """
 
-    def __init__(self, mr_id: Optional[int], add_comment_impl: Optional[Callable[[str], None]] = None):
+    def __init__(self, mr_id: Optional[int], add_comment_impl: Optional[Callable[[str], None]] = None,
+                 enable_auto_merge_impl: Optional[Callable[[], None]] = None):
         self.id = mr_id
         self._add_comment_impl = add_comment_impl
+        self._enable_auto_merge_impl = enable_auto_merge_impl
 
     def add_comment(self, comment: str):
         if self._add_comment_impl is None:
             return
         self._add_comment_impl(resolve(comment))
 
+    def enable_auto_merge(self):
+        if self._enable_auto_merge_impl is None:
+            return
+        self._enable_auto_merge_impl()
+
     @classmethod
     def Skip(cls) -> "MergeRequestHook":
         # No MR created, provide a hook that only logs on add_comment

valhalla/common/get_config.py

@@ -19,12 +19,14 @@ def __repr__(self):
 
 
 class MergeRequestConfig:
-    def __init__(self, enabled: bool, target_branch: str, title: str, description: str, reviewers: List[str]):
+    def __init__(self, enabled: bool, target_branch: str, title: str, description: str, reviewers: List[str],
+                 auto_merge: bool = False):
         self.enabled = enabled
         self.target_branch = target_branch
         self.title = title
         self.description = description
         self.reviewers = reviewers
+        self.auto_merge = auto_merge
 
     def __repr__(self):
         return f"\n" \
@@ -34,6 +36,7 @@ def __repr__(self):
                f"     title={self.title} \n" \
                f"     description={self.description} \n" \
                f"     reviewers={self.reviewers} \n" \
+               f"     auto_merge={self.auto_merge} \n" \
                f"   )"
 
 
@@ -303,11 +306,13 @@ def get_merge_request_part(merge_request_dict: dict) -> MergeRequestConfig:
     description = get_from_dict(merge_request_dict, 'description', False)
 
     reviewers = get_from_dict(merge_request_dict, 'reviewers', False)
+    auto_merge = bool(get_from_dict(merge_request_dict, 'auto_merge', False))
     return MergeRequestConfig(enabled,
                               target_branch,
                               get_default_merge_request_title(title),
                               get_default_merge_request_description(description),
-                              reviewers)
+                              reviewers,
+                              auto_merge)
 
 
 def get_default_merge_request_title(title: str):

valhalla/main.py

@@ -113,6 +113,7 @@ def start():
     commit(config.commit_after_release, token)
 
     mr_hook.add_comment(f"✅ Release successful! Now wait for tagged version to be build. CC @{{AUTHOR}}")
+    mr_hook.enable_auto_merge()
 
 
 def __version_to_release(git_host: GitHost) -> VersionToRelease: