fix: check last fast-track request comment (#606)

Refs: nodejs/node#42141

lib/pr_checker.js

@@ -169,7 +169,7 @@ export default class PRChecker {
     }
 
     if (isFastTracked) {
-      const comment = this.comments.find((c) =>
+      const comment = [...this.comments].reverse().find((c) =>
         FAST_TRACK_RE.test(c.bodyText));
       if (!comment) {
         cli.error('Unable to find the fast-track request comment.');

test/fixtures/comments_with_two_fast_track.json

@@ -0,0 +1,36 @@
+[
+  {
+    "publishedAt": "2017-10-22T04:16:36.458Z",
+    "bodyText": "Fast-track has been requested by @bar. Please 👍 to approve.",
+    "author": {
+      "login": "github-actions"
+    },
+    "reactions": {
+      "nodes": []
+    }
+  },
+  {
+    "publishedAt": "2017-10-22T04:17:36.458Z",
+    "bodyText": "Oups.",
+    "author": {
+      "login": "bar"
+    },
+    "reactions": {
+      "nodes": []
+    }
+  },
+  {
+    "publishedAt": "2017-10-22T05:16:36.458Z",
+    "bodyText": "Fast-track has been requested by @bar. Please 👍 to approve.",
+    "author": {
+      "login": "github-actions"
+    },
+    "reactions": {
+      "nodes": [
+        { "user": { "login": "bar" } },
+        { "user": { "login": "foo" } },
+        { "user": { "login": "Baz" } }
+      ]
+    }
+  }
+]

test/fixtures/data.js

@@ -35,6 +35,8 @@ export const requestingChangesReviews =
   readJSON('reviews_requesting_changes.json');
 
 export const commentsWithFastTrack = readJSON('comments_with_fast_track.json');
+export const commentsWithTwoFastTrack =
+  readJSON('comments_with_two_fast_track.json');
 export const commentsWithFastTrackInsuffientApprovals =
   readJSON('comments_with_fast_track_insufficient_approvals.json');
 export const commentsWithCI = readJSON('comments_with_ci.json');

test/unit/pr_checker.test.js

@@ -17,6 +17,7 @@ import {
   requestingChangesReviews,
   noReviewers,
   commentsWithFastTrack,
+  commentsWithTwoFastTrack,
   commentsWithFastTrackInsuffientApprovals,
   commentsWithCI,
   commentsWithFailedCI,
@@ -534,6 +535,53 @@ describe('PRChecker', () => {
       cli.assertCalledWith(expectedLogs);
     });
 
+    it('should check the last fast-track request comment', () => {
+      const cli = new TestCLI();
+
+      const expectedLogs = {
+        ok:
+         [['Approvals: 4'],
+           ['- Foo User (@foo): https://github.com/nodejs/node/pull/16438#pullrequestreview-71480624'],
+           ['- Quux User (@Quux): LGTM'],
+           ['- Baz User (@Baz): https://github.com/nodejs/node/pull/16438#pullrequestreview-71488236'],
+           ['- Bar User (@bar) (TSC): lgtm']],
+        info:
+         [['This PR was created on Fri, 30 Nov 2018 17:50:44 GMT'],
+           ['This PR is being fast-tracked']]
+      };
+
+      const pr = Object.assign({}, firstTimerPR, {
+        author: {
+          login: 'bar'
+        },
+        createdAt: LT_48H,
+        labels: {
+          nodes: [
+            { name: 'fast-track' }
+          ]
+        }
+      });
+
+      const data = {
+        pr,
+        reviewers: allGreenReviewers,
+        comments: commentsWithTwoFastTrack,
+        reviews: approvingReviews,
+        commits: [],
+        collaborators,
+        authorIsNew: () => true,
+        getThread() {
+          return PRData.prototype.getThread.call(this);
+        }
+      };
+      const checker = new PRChecker(cli, data, {}, argv);
+
+      cli.clearCalls();
+      const status = checker.checkReviewsAndWait(new Date(NOW));
+      assert(status);
+      cli.assertCalledWith(expectedLogs);
+    });
+
     it('should error with 1 fast-track approval from the pr author', () => {
       const cli = new TestCLI();