From 3d6493a23a8df035c4272fea852068042da6f166 Mon Sep 17 00:00:00 2001
From: Matt Benson <gudnabrsam@gmail.com>
Date: Wed, 14 May 2025 17:03:47 -0500
Subject: [PATCH] Support merge request labels in publish:gitlab:merge-request

Signed-off-by: Matt Benson <gudnabrsam@gmail.com>
---
 .changeset/small-dots-march.md                |  5 ++
 .../report.api.md                             |  1 +
 .../src/actions/gitlabMergeRequest.test.ts    | 62 +++++++++++++++++++
 .../src/actions/gitlabMergeRequest.ts         |  8 +++
 4 files changed, 76 insertions(+)
 create mode 100644 .changeset/small-dots-march.md

diff --git a/.changeset/small-dots-march.md b/.changeset/small-dots-march.md
new file mode 100644
index 0000000000..0796ef68bb
--- /dev/null
+++ b/.changeset/small-dots-march.md
@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-scaffolder-backend-module-gitlab': patch
+---
+
+Support merge request labels in publish:gitlab:merge-request
diff --git a/plugins/scaffolder-backend-module-gitlab/report.api.md b/plugins/scaffolder-backend-module-gitlab/report.api.md
index 335c013ada..ed0d4b66a9 100644
--- a/plugins/scaffolder-backend-module-gitlab/report.api.md
+++ b/plugins/scaffolder-backend-module-gitlab/report.api.md
@@ -206,6 +206,7 @@ export const createPublishGitlabMergeRequestAction: (options: {
     assignee?: string | undefined;
     reviewers?: string[] | undefined;
     assignReviewersFromApprovalRules?: boolean | undefined;
+    labels?: string | string[] | undefined;
   },
   {
     targetBranchName: string;
diff --git a/plugins/scaffolder-backend-module-gitlab/src/actions/gitlabMergeRequest.test.ts b/plugins/scaffolder-backend-module-gitlab/src/actions/gitlabMergeRequest.test.ts
index 5e7ac3d908..0cc1ca60c3 100644
--- a/plugins/scaffolder-backend-module-gitlab/src/actions/gitlabMergeRequest.test.ts
+++ b/plugins/scaffolder-backend-module-gitlab/src/actions/gitlabMergeRequest.test.ts
@@ -1446,4 +1446,66 @@ describe('createGitLabMergeRequest', () => {
       );
     });
   });
+  describe('with labels', () => {
+    it('handles single label', async () => {
+      const input = {
+        repoUrl: 'gitlab.com?repo=repo&owner=owner',
+        title: 'Create my new MR',
+        branchName: 'new-mr',
+        description: 'MR description',
+        commitAction: 'skip',
+        labels: 'single-label',
+      };
+      const ctx = createMockActionContext({ input, workspacePath });
+      await instance.handler(ctx);
+
+      expect(mockGitlabClient.Branches.create).toHaveBeenCalledWith(
+        'owner/repo',
+        'new-mr',
+        'main',
+      );
+      expect(mockGitlabClient.Commits.create).not.toHaveBeenCalled();
+      expect(mockGitlabClient.MergeRequests.create).toHaveBeenCalledWith(
+        'owner/repo',
+        'new-mr',
+        'main',
+        'Create my new MR',
+        {
+          description: 'MR description',
+          removeSourceBranch: false,
+          labels: 'single-label',
+        },
+      );
+    });
+    it('handles array of labels', async () => {
+      const input = {
+        repoUrl: 'gitlab.com?repo=repo&owner=owner',
+        title: 'Create my new MR',
+        branchName: 'new-mr',
+        description: 'MR description',
+        commitAction: 'skip',
+        labels: ['foo', 'bar', 'baz'],
+      };
+      const ctx = createMockActionContext({ input, workspacePath });
+      await instance.handler(ctx);
+
+      expect(mockGitlabClient.Branches.create).toHaveBeenCalledWith(
+        'owner/repo',
+        'new-mr',
+        'main',
+      );
+      expect(mockGitlabClient.Commits.create).not.toHaveBeenCalled();
+      expect(mockGitlabClient.MergeRequests.create).toHaveBeenCalledWith(
+        'owner/repo',
+        'new-mr',
+        'main',
+        'Create my new MR',
+        {
+          description: 'MR description',
+          removeSourceBranch: false,
+          labels: ['foo', 'bar', 'baz'],
+        },
+      );
+    });
+  });
 });
diff --git a/plugins/scaffolder-backend-module-gitlab/src/actions/gitlabMergeRequest.ts b/plugins/scaffolder-backend-module-gitlab/src/actions/gitlabMergeRequest.ts
index 65023eda1e..a9ee80a30f 100644
--- a/plugins/scaffolder-backend-module-gitlab/src/actions/gitlabMergeRequest.ts
+++ b/plugins/scaffolder-backend-module-gitlab/src/actions/gitlabMergeRequest.ts
@@ -222,6 +222,12 @@ _deprecated_: \`projectid\` passed as query parameters in the \`repoUrl\``,
             .describe(
               'Automatically assign reviewers from the approval rules of the MR. Includes `CODEOWNERS`',
             ),
+        labels: z =>
+          z
+            .string()
+            .or(z.string().array())
+            .optional()
+            .describe('Labels with which to tag the created merge request'),
       },
       output: {
         targetBranchName: z =>
@@ -245,6 +251,7 @@ _deprecated_: \`projectid\` passed as query parameters in the \`repoUrl\``,
         sourcePath,
         title,
         token,
+        labels,
       } = ctx.input;
 
       const { owner, repo, project } = parseRepoUrl(repoUrl, integrations);
@@ -453,6 +460,7 @@ _deprecated_: \`projectid\` passed as query parameters in the \`repoUrl\``,
                   : false,
                 assigneeId,
                 reviewerIds,
+                labels,
               },
             );
             return {