fix: add cron job to pick up hanging prs

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

@@ -39,12 +39,12 @@ interface WatchPR {
   repo: string;
   owner: string;
   state: 'continue' | 'stop';
-  branchProtection: string[];
+  branchProtection?: string[];
   label: string;
   author: string;
   url: string;
-  reactionId: number;
-  installationId: number;
+  reactionId?: number | undefined;
+  installationId?: number;
 }
 
 interface Label {
@@ -132,7 +132,7 @@ handler.cleanUpPullRequest = async function cleanUpPullRequest(
   repo: string,
   prNumber: number,
   label: string,
-  reactionId: number,
+  reactionId: number | undefined,
   github: Context['github']
 ) {
   await github.issues.removeLabel({
@@ -141,12 +141,85 @@ handler.cleanUpPullRequest = async function cleanUpPullRequest(
     issue_number: prNumber,
     name: label,
   });
-  await github.reactions.deleteForIssue({
-    owner,
-    repo,
-    issue_number: prNumber,
-    reaction_id: reactionId,
-  });
+  if (reactionId) {
+    await github.reactions.deleteForIssue({
+      owner,
+      repo,
+      issue_number: prNumber,
+      reaction_id: reactionId,
+    });
+  }
+};
+
+/**
+ * Checks if a branch with a PR has branch protection, if not, comments on PR
+ * @param owner type string
+ * @param repo type string
+ * @param prNumber type number
+ * @param github type githup API surface from payload
+ */
+handler.checkForBranchProtection = async function checkForBranchProtection(
+  owner: string,
+  repo: string,
+  prNumber: number,
+  github: Context['github']
+): Promise<string[] | undefined> {
+  let branchProtection: string[] | undefined;
+
+  // Check to see if branch protection exists
+  try {
+    branchProtection = (
+      await github.repos.getBranchProtection({
+        owner,
+        repo,
+        branch: 'master',
+      })
+    ).data.required_status_checks.contexts;
+    logger.info(
+      `checking branch protection for ${owner}/${repo}: ${branchProtection}`
+    );
+    // if branch protection doesn't exist, leave a comment on the PR;
+  } catch (err) {
+    err.message = `Error in getting branch protection\n\n${err.message}`;
+    await github.issues.createComment({
+      owner,
+      repo,
+      issue_number: prNumber,
+      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);
+  }
+  return branchProtection;
+};
+
+/**
+ * Attempts to create a reaction on the PR, returns the reaction ID
+ * @param owner type string
+ * @param repo type string
+ * @param prNumber type number
+ * @param github type githup API surface from payload
+ */
+handler.createReaction = async function createReaction(
+  owner: string,
+  repo: string,
+  prNumber: number,
+  github: Context['github']
+): Promise<number | undefined> {
+  let reactionId: number | undefined;
+  try {
+    reactionId = (
+      await github.reactions.createForIssue({
+        owner,
+        repo,
+        issue_number: prNumber,
+        content: 'eyes',
+      })
+    ).data.id;
+  } catch (err) {
+    logger.error(err);
+  }
+  return reactionId;
 };
 
 /**
@@ -156,14 +229,15 @@ handler.cleanUpPullRequest = async function cleanUpPullRequest(
  * @param prNumber type number
  * @param label type string
  * @param reactionId type number or null
+ * @param url type string
  * @param github type githup API surface from payload
  */
 handler.checkIfPRIsInvalid = async function checkIfPRIsInvalid(
   owner: string,
   repo: string,
   prNumber: number,
   label: string,
-  reactionId: number,
+  reactionId: number | undefined,
   url: string,
   github: Context['github']
 ) {
@@ -214,29 +288,56 @@ handler.checkIfPRIsInvalid = async function checkIfPRIsInvalid(
 };
 
 /**
- * Adds a PR to datastore when an automerge label is added to a PR
+ * Adds a PR to datastore; first, checks if there's branch protection and adds a reaction Id
  * @param url type string
  * @param wp type Watch PR (owner, repo, pr number, state, url)
+ * @param github type githup API surface from payload
  * @returns void
  */
-handler.addPR = async function addPR(wp: WatchPR, url: string) {
-  const key = datastore.key([TABLE, url]);
-  const entity = {
-    key,
-    data: {
-      created: new Date().toJSON(),
-      owner: wp.owner,
-      repo: wp.repo,
-      number: wp.number,
-      branchProtection: wp.branchProtection,
-      label: wp.label,
-      author: wp.author,
-      reactionId: wp.reactionId,
-      installationId: wp.installationId,
-    },
-    method: 'upsert',
-  };
-  await datastore.save(entity);
+handler.addPR = async function addPR(
+  wp: WatchPR,
+  url: string,
+  github: Context['github']
+) {
+  // Since a PR cannot be merged without required status checks, we'll check if they exist first
+  const branchProtection = await handler.checkForBranchProtection(
+    wp.owner,
+    wp.repo,
+    wp.number,
+    github
+  );
+  let reactionId: number | undefined;
+  // If the status checks exist, we'll try to react to the PR
+  if (branchProtection) {
+    try {
+      reactionId = await handler.createReaction(
+        wp.owner,
+        wp.repo,
+        wp.number,
+        github
+      );
+    } catch (err) {
+      logger.error(err);
+    }
+    //then, we'll add the PR to the Datastore table
+    const key = datastore.key([TABLE, url]);
+    const entity = {
+      key,
+      data: {
+        created: new Date().toJSON(),
+        owner: wp.owner,
+        repo: wp.repo,
+        number: wp.number,
+        branchProtection: branchProtection,
+        label: wp.label,
+        author: wp.author,
+        reactionId: wp.reactionId,
+        installationId: reactionId,
+      },
+      method: 'upsert',
+    };
+    await datastore.save(entity);
+  }
 };
 
 /**
@@ -300,7 +401,7 @@ handler.checkPRMergeability = async function checkPRMergeability(
             wp.number,
             [MERGE_ON_GREEN_LABEL, MERGE_ON_GREEN_LABEL_SECURE],
             wp.state,
-            wp.branchProtection,
+            wp.branchProtection!,
             wp.label,
             wp.author,
             github
@@ -331,6 +432,77 @@ handler.checkPRMergeability = async function checkPRMergeability(
   }
 };
 
+//TODO: change the search query if expanding the allowlist to search for more authors
+/**
+ * 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']
+) {
+  // Github does not support searching the labels with 'OR'.
+  // The searching for issues is considered to be an "AND" instead of an "OR" .
+  const issuesAutomergeLabel = await github.paginate(
+    await github.search.issuesAndPullRequests,
+    {
+      q:
+        'is:open is:pr user:googleapis user:GoogleCloudPlatform label:"automerge"',
+    }
+  );
+
+  const issuesAutomergeExactLabel = await github.paginate(
+    await github.search.issuesAndPullRequests,
+    {
+      q:
+        'is:open is:pr user:googleapis user:GoogleCloudPlatform label:"automerge: exact"',
+    }
+  );
+  for (const issue of issuesAutomergeLabel) {
+    logger.info('before getting PR');
+    const pullRequestInDatastore: WatchPR = await handler.getPR(issue.html_url);
+    if (!pullRequestInDatastore) {
+      logger.info('before adding PR');
+      await handler.addPR(
+        {
+          number: issue.number,
+          owner,
+          repo,
+          state: 'continue',
+          url: issue.html_url,
+          label: 'automerge',
+          author: issue.user.login,
+        },
+        issue.html_url,
+        github
+      );
+    }
+  }
+
+  for (const issue of issuesAutomergeExactLabel) {
+    const pullRequestInDatastore: WatchPR = await handler.getPR(issue.html_url);
+    if (!pullRequestInDatastore) {
+      await handler.addPR(
+        {
+          number: issue.number,
+          owner,
+          repo,
+          state: 'continue',
+          url: issue.html_url,
+          label: 'automerge: exact',
+          author: issue.user.login,
+        },
+        issue.html_url,
+        github
+      );
+    }
+  }
+};
+
 // TODO: refactor into multiple function exports, this will take some work in
 // gcf-utils.
 
@@ -350,6 +522,22 @@ 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`);
@@ -396,60 +584,20 @@ function handler(app: Application) {
       return;
     }
 
-    // check to see if the owner has branch protection rules
-    let branchProtection: string[] | undefined;
-    try {
-      branchProtection = (
-        await context.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 context.github.issues.createComment({
+    await handler.addPR(
+      {
+        number: prNumber,
         owner,
         repo,
-        issue_number: prNumber,
-        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 context.github.reactions.createForIssue({
-          owner,
-          repo,
-          issue_number: prNumber,
-          content: 'eyes',
-        })
-      ).data.id;
-
-      await handler.addPR(
-        {
-          number: prNumber,
-          owner,
-          repo,
-          state: 'continue',
-          url: context.payload.pull_request.html_url,
-          branchProtection: branchProtection,
-          label: label.name,
-          author,
-          reactionId,
-          installationId,
-        },
-        context.payload.pull_request.html_url
-      );
-    }
+        state: 'continue',
+        url: context.payload.pull_request.html_url,
+        label: label.name,
+        author,
+        installationId,
+      },
+      context.payload.pull_request.html_url,
+      context.github
+    );
   });
 
   app.on(['pull_request.unlabeled'], async context => {