fix(manage-merge-queue): don't remove queued pr if queue is full (#698)

Author: danadajian

dist/284.index.js

@@ -77,13 +77,15 @@ export const manageMergeQueue = async ({
 
   const queuedPrs = await getQueuedPullRequests();
   const queuePosition = queuedPrs.length + 1;
+  const prAttemptingToJoinQueue = pullRequest.labels.every(label => !label.name?.startsWith(QUEUED_FOR_MERGE_PREFIX));
 
-  if (queuePosition > Number(max_queue_size)) {
+  if (prAttemptingToJoinQueue && queuePosition > Number(max_queue_size)) {
     await createPrComment({
       body: `The merge queue is full! Only ${max_queue_size} PRs are allowed in the queue at a time.\n\nIf you would like to merge your PR, please monitor the PRs in the queue and make sure the authors are around to merge them.`
     });
     return removePrFromQueue(pullRequest);
   }
+
   if (pullRequest.labels.find(label => label.name === JUMP_THE_QUEUE_PR_LABEL)) {
     if (allow_only_for_maintainers === 'true') {
       core.info(`Checking if user ${login} is a maintainer...`);
@@ -99,8 +101,7 @@ export const manageMergeQueue = async ({
     return updateMergeQueue(queuedPrs);
   }
 
-  const prIsAlreadyInTheQueue = pullRequest.labels.find(label => label.name?.startsWith(QUEUED_FOR_MERGE_PREFIX));
-  if (!prIsAlreadyInTheQueue) {
+  if (prAttemptingToJoinQueue) {
     await addPrToQueue(pullRequest, queuePosition, skip_auto_merge);
   }
 

dist/284.index.js.map

@@ -710,6 +710,43 @@ describe('manageMergeQueue', () => {
     });
   });
 
+  describe('should not remove queued pr when queue is maxed out', () => {
+    const prUnderTest = {
+      number: 2,
+      merged: false,
+      head: { sha: 'sha' },
+      labels: [{ name: READY_FOR_MERGE_PR_LABEL }, { name: 'QUEUED FOR MERGE #2' }]
+    };
+    const openPrs = [
+      prUnderTest,
+      { number: 1, labels: [{ name: READY_FOR_MERGE_PR_LABEL }, { name: 'QUEUED FOR MERGE #1' }] },
+      { number: 2, labels: [{ name: READY_FOR_MERGE_PR_LABEL }, { name: 'QUEUED FOR MERGE #2' }] },
+      { number: 3, labels: [{ name: READY_FOR_MERGE_PR_LABEL }, { name: 'QUEUED FOR MERGE #3' }] }
+    ];
+    beforeEach(async () => {
+      (octokit.pulls.list as unknown as Mocktokit).mockImplementation(async ({ page }) => ({
+        data: page === 1 ? openPrs : []
+      }));
+      (octokit.pulls.get as unknown as Mocktokit).mockImplementation(async () => ({
+        data: prUnderTest
+      }));
+      (approvalsSatisfied as jest.Mock).mockResolvedValue(true);
+      await manageMergeQueue({
+        max_queue_size: '3'
+      });
+    });
+
+    it('should not remove queued pr when queue is full', () => {
+      expect(createPrComment).not.toHaveBeenCalled();
+      expect(setCommitStatus).toHaveBeenCalledWith({
+        sha: 'sha',
+        context: MERGE_QUEUE_STATUS,
+        state: 'pending',
+        description: 'This PR is in line to merge.'
+      });
+    });
+  });
+
   describe('fewer than max prs in the queue', () => {
     const prUnderTest = {
       number: 1,