feat: add support for commit revert API (#991)

docs/gl_objects/commits.rst

@@ -72,6 +72,10 @@ Cherry-pick a commit into another branch::
 
     commit.cherry_pick(branch='target_branch')
 
+Revert a commit on a given branch::
+
+    commit.revert(branch='target_branch')
+
 Get the references the commit has been pushed to (branches and tags)::
 
     commit.refs()  # all references

gitlab/exceptions.py

@@ -245,6 +245,10 @@ class GitlabRepairError(GitlabOperationError):
     pass
 
 
+class GitlabRevertError(GitlabOperationError):
+    pass
+
+
 class GitlabLicenseError(GitlabOperationError):
     pass
 

gitlab/v4/objects.py

@@ -2136,6 +2136,22 @@ def merge_requests(self, **kwargs):
         path = "%s/%s/merge_requests" % (self.manager.path, self.get_id())
         return self.manager.gitlab.http_get(path, **kwargs)
 
+    @cli.register_custom_action("ProjectCommit", ("branch",))
+    @exc.on_http_error(exc.GitlabRevertError)
+    def revert(self, branch, **kwargs):
+        """Revert a commit on a given branch.
+
+        Args:
+            branch (str): Name of target branch
+            **kwargs: Extra options to send to the server (e.g. sudo)
+
+        Raises:
+            GitlabAuthenticationError: If authentication is not correct
+            GitlabRevertError: If the revert could not be performed
+        """
+        path = "%s/%s/revert" % (self.manager.path, self.get_id())
+        post_data = {"branch": branch}
+        self.manager.gitlab.http_post(path, post_data=post_data, **kwargs)
 
 class ProjectCommitManager(RetrieveMixin, CreateMixin, RESTManager):
     _path = "/projects/%(project_id)s/repository/commits"

tools/cli_test_v4.sh

@@ -100,6 +100,15 @@ testcase "merge request validation" '
         --iid "$MR_ID" >/dev/null 2>&1
 '
 
+# Test revert commit
+COMMITS=$(GITLAB -v project-commit list --project-id "${PROJECT_ID}")
+COMMIT_ID=$(pecho "${COMMITS}" | grep -m1 '^id:' | cut -d' ' -f2)
+
+testcase "revert commit" '
+    GITLAB project-commit revert --project-id "$PROJECT_ID" \
+        --id "$COMMIT_ID" --branch master
+'
+
 # Test project labels
 testcase "create project label" '
     OUTPUT=$(GITLAB -v project-label create --project-id $PROJECT_ID \

tools/python_test_v4.py

@@ -462,6 +462,21 @@
 discussion = commit.discussions.get(discussion.id)
 # assert len(discussion.attributes["notes"]) == 1
 
+# Revert commit
+commit.revert(branch="master")
+revert_commit = admin_project.commits.list()[0]
+
+expected_message = "Revert \"{}\"\n\nThis reverts commit {}".format(
+    commit.message, commit.id)
+assert revert_commit.message == expected_message
+
+try:
+    commit.revert(branch="master")
+    # Only here to really ensure expected error without a full test framework
+    raise AssertionError("Two revert attempts should raise GitlabRevertError")
+except gitlab.GitlabRevertError:
+    pass
+
 # housekeeping
 admin_project.housekeeping()