fix: add cron job to pick up hanging prs

packages/merge-on-green/src/merge-on-green.ts

@@ -44,7 +44,7 @@ interface WatchPR {
   author: string;
   url: string;
   reactionId: number;
-  installationId: number;
+  installationId?: number;
 }
 
 interface Label {
@@ -331,6 +331,98 @@ handler.checkPRMergeability = async function checkPRMergeability(
   }
 };
 
+/**
+ * For a given repository, looks through all the PRs and checks to see if they have a MOG label
+ * @param owner the owner of the repo
+ * @param repo the repo name
+ * @param context the context of the webhook payload
+ * @returns void
+ */
+handler.pickUpPR = async function pickUpPR(
+  owner: string,
+  repo: string,
+  github: Context['github']
+) {
+  const prs = await github.paginate(await github.pulls.list, {
+    owner,
+    repo,
+    state: 'open',
+  });
+
+  for (const pr of prs) {
+    const labels = await github.paginate(
+      await github.issues.listLabelsOnIssue,
+      {
+        owner,
+        repo,
+        issue_number: pr.number,
+      }
+    );
+
+    const labelFound = labels.find(
+      (label: Label) =>
+        label.name === MERGE_ON_GREEN_LABEL ||
+        label.name === MERGE_ON_GREEN_LABEL_SECURE
+    );
+
+    if (labelFound) {
+      // check to see if the owner has branch protection rules
+      let branchProtection: string[] | undefined;
+      try {
+        branchProtection = (
+          await github.repos.getBranchProtection({
+            owner,
+            repo,
+            branch: 'master',
+          })
+        ).data.required_status_checks.contexts;
+        logger.info(
+          `checking branch protection for ${owner}/${repo}: ${branchProtection}`
+        );
+      } catch (err) {
+        err.message = `Error in getting branch protection\n\n${err.message}`;
+        await github.issues.createComment({
+          owner,
+          repo,
+          issue_number: pr.number,
+          body:
+            "Your PR doesn't have any required checks. Please add required checks to your master branch and then re-add the label. Learn more about enabling these checks here: https://help.github.com/en/github/administering-a-repository/enabling-required-status-checks.",
+        });
+        logger.error(err);
+      }
+
+      // if the owner has branch protection set up, add this PR to the Datastore table
+      if (branchProtection) {
+        // try to create reaction. Save this reaction in the Datastore table since I don't (think)
+        // it is on the pull_request payload.
+        const reactionId = (
+          await github.reactions.createForIssue({
+            owner,
+            repo,
+            issue_number: pr.number,
+            content: 'eyes',
+          })
+        ).data.id;
+
+        await handler.addPR(
+          {
+            number: pr.number,
+            owner,
+            repo,
+            state: 'continue',
+            url: pr.html_url,
+            branchProtection: branchProtection,
+            label: labelFound.name,
+            author: pr.user.login,
+            reactionId,
+          },
+          pr.html_url
+        );
+      }
+    }
+  }
+};
+
 // TODO: refactor into multiple function exports, this will take some work in
 // gcf-utils.
 
@@ -350,6 +442,22 @@ function handler(app: Application) {
       await handler.cleanDatastoreTable(watchedPRs, app, context);
       return;
     }
+
+    //because we're searching for the PRs, and not getting the installation ID, we have to use
+    //the bot's installation ID to call the API. So, we need to make sure it matches the repo owner
+    if (context.payload.cron_org) {
+      logger.info('Entering job to pick up any hanging PRs');
+      const owner = context.payload.organization.login;
+      const repo = context.payload.repository.name;
+
+      if (context.payload.cron_org !== owner) {
+        logger.info(`skipping run for ${context.payload.cron_org}`);
+        return;
+      }
+      await handler.pickUpPR(owner, repo, context.github);
+      return;
+    }
+
     const start = Date.now();
     await handler.checkPRMergeability(watchedPRs, app, context);
     logger.info(`mergeOnGreen check took ${Date.now() - start}ms`);

packages/merge-on-green/test/merge-on-green.ts

@@ -37,6 +37,17 @@ interface CheckRuns {
   conclusion: string;
 }
 
+interface PR {
+  number: number;
+  owner: string;
+  repo: string;
+  state: string;
+  html_url: string;
+  user: {
+    login: string;
+  };
+}
+
 nock.disableNetConnect();
 
 const fixturesPath = resolve(__dirname, '../../test/Fixtures');
@@ -168,6 +179,12 @@ function getPR(mergeable: boolean, mergeableState: string, state: string) {
     });
 }
 
+function getPRsForRepo(pr: PR[]) {
+  return nock('https://api.github.com')
+    .get('/repos/testOwner/testRepo/pulls?state=open')
+    .reply(200, pr);
+}
+
 //meta-note about the schedule.repository as any; currently GH does not support this type, see
 //open issue for a fix: https://github.com/octokit/webhooks.js/issues/277
 describe('merge-on-green', () => {
@@ -892,6 +909,116 @@ describe('merge-on-green', () => {
       });
     });
 
+    describe('pick up PRs', () => {
+      it('adds a PR if the PR was not picked up by a webhook event', async () => {
+        const scopes = [
+          getPRsForRepo([
+            {
+              number: 1,
+              owner: 'testOwner',
+              repo: 'testRepo',
+              state: 'continue',
+              html_url: 'https://github.com/testOwner/testRepo/pull/6',
+              user: {
+                login: 'testOwner',
+              },
+            },
+          ]),
+          getLabels('automerge'),
+          react(),
+          getBranchProtection(200, ['Special Check']),
+        ];
+
+        await probot.receive({
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
+          name: 'schedule.repository' as any,
+          payload: {
+            repository: {
+              name: 'testRepo',
+              owner: {
+                login: 'testOwner',
+              },
+            },
+            organization: {
+              login: 'testOwner',
+            },
+            org: 'testOwner',
+            cron_org: 'testOwner',
+          },
+          id: 'abc123',
+        });
+
+        scopes.forEach(s => s.done());
+        assert(addPRStub.called);
+      });
+
+      it('does not add a PR if no labels were found', async () => {
+        const scopes = [
+          getPRsForRepo([
+            {
+              number: 1,
+              owner: 'testOwner',
+              repo: 'testRepo',
+              state: 'continue',
+              html_url: 'https://github.com/testOwner/testRepo/pull/6',
+              user: {
+                login: 'testOwner',
+              },
+            },
+          ]),
+          getLabels('notTheRightLabel'),
+        ];
+
+        await probot.receive({
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
+          name: 'schedule.repository' as any,
+          payload: {
+            repository: {
+              name: 'testRepo',
+              owner: {
+                login: 'testOwner',
+              },
+            },
+            organization: {
+              login: 'testOwner',
+            },
+            org: 'testOwner',
+            cron_org: 'testOwner',
+          },
+          id: 'abc123',
+        });
+
+        scopes.forEach(s => s.done());
+        assert(!addPRStub.called);
+      });
+
+      it('does not add a PR if no PRs were found', async () => {
+        const scopes = [getPRsForRepo([])];
+
+        await probot.receive({
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
+          name: 'schedule.repository' as any,
+          payload: {
+            repository: {
+              name: 'testRepo',
+              owner: {
+                login: 'testOwner',
+              },
+            },
+            organization: {
+              login: 'testOwner',
+            },
+            org: 'testOwner',
+            cron_org: 'testOwner',
+          },
+          id: 'abc123',
+        });
+
+        scopes.forEach(s => s.done());
+        assert(!addPRStub.called);
+      });
+    });
+
     describe('PRs when labeled', () => {
       handler.allowlist = ['testOwner'];
       it('adds a PR when label is added correctly', async () => {