feat: request review from original author on manual backports

spec/operations.spec.ts

@@ -473,15 +473,17 @@ describe('runner', () => {
   describe('updateManualBackport()', { timeout: 30_000 }, () => {
     const octokit = {
       pulls: {
-        get: vi.fn().mockResolvedValue({}),
+        get: vi.fn().mockResolvedValue({
+          data: { user: { login: 'original-author' } },
+        }),
       },
       issues: {
         createComment: vi.fn().mockResolvedValue({}),
         listComments: vi.fn().mockResolvedValue({ data: [] }),
       },
     };
 
-    it('tags reviewers on manual backport creation', async () => {
+    it('tags reviewers and requests review from the original author on manual backport creation', async () => {
       const context = {
         ...backportPROpenedEvent,
         octokit,
@@ -492,6 +494,30 @@ describe('runner', () => {
       expect(tagBackportReviewers).toHaveBeenCalledWith({
         context,
         targetPrNumber: 7,
+        user: 'original-author',
+      });
+    });
+
+    it('does not request review from the original author if they opened the manual backport', async () => {
+      const context = {
+        ...backportPROpenedEvent,
+        octokit: {
+          ...octokit,
+          pulls: {
+            // The author of the manual backport PR in the fixture.
+            get: vi.fn().mockResolvedValue({
+              data: { user: { login: 'codebytere' } },
+            }),
+          },
+        },
+        repo: vi.fn(),
+      };
+      await updateManualBackport(context, PRChange.OPEN, 1234);
+      expect(tagBackportReviewers).toHaveBeenCalled();
+      expect(tagBackportReviewers).toHaveBeenCalledWith({
+        context,
+        targetPrNumber: 7,
+        user: undefined,
       });
     });
 

src/operations/update-manual-backport.ts

@@ -139,10 +139,17 @@ please check out #${pr.number}`;
       );
     }
 
-    // Tag default reviewers to manual backport
+    // Tag default reviewers to manual backport, as well as the original
+    // PR author if they have write access. GitHub doesn't allow requesting
+    // a review from the PR author, so skip that if they backported it
+    // themselves.
     await tagBackportReviewers({
       context,
       targetPrNumber: pr.number,
+      user:
+        originalPR.user?.login === pr.user.login
+          ? undefined
+          : originalPR.user?.login,
     });
   } else if (type === PRChange.MERGE) {
     log(