feat: add retry when trying to merge

ridedott · Aug 4, 2020 · e686145 · e686145
1 parent ac42c5b
commit e686145
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Showing 9 changed files with 96 additions and 39 deletions.
diff --git a/cSpell.json b/cSpell.json
@@ -25,6 +25,7 @@
   "language": "en-US",
   "version": "0.1",
   "words": [
+    "backoff",
     "codeowners",
     "commitlint",
     "coverallsapp",

diff --git a/src/common/merge.ts b/src/common/merge.ts
@@ -7,30 +7,53 @@ import {
 import { parseInputMergeMethod } from '../utilities/inputParsers';
 import { logDebug, logInfo } from '../utilities/log';
 
+export interface PullRequestDetails {
+  commitHeadline: string;
+  pullRequestId: string;
+  reviewEdge: { node: { state: string } } | undefined;
+}
+
+const EXPONENTIAL_BACKOFF = 2;
+const WAIT_TIME_SECONDS = 1000;
+
+const delay = async (duration: number): Promise<void> => {
+  return new Promise((resolve: () => void): void => {
+    setTimeout((): void => {
+      resolve();
+    }, duration);
+  });
+};
+
 /**
  * Approves and merges a given Pull Request.
  */
 export const merge = async (
   octokit: ReturnType<typeof getOctokit>,
-  {
-    commitHeadline,
-    pullRequestId,
-    reviewEdge,
-  }: {
-    commitHeadline: string;
-    pullRequestId: string;
-    reviewEdge: { node: { state: string } } | undefined;
-  },
+  pullRequestDetails: PullRequestDetails,
 ): Promise<void> => {
   const mergeMethod = parseInputMergeMethod();
 
+  const { commitHeadline, pullRequestId, reviewEdge } = pullRequestDetails;
+
   const mutation =
     reviewEdge === undefined
       ? approveAndMergePullRequestMutation(mergeMethod)
       : mergePullRequestMutation(mergeMethod);
 
+  await octokit.graphql(mutation, { commitHeadline, pullRequestId });
+};
+
+export const mergeWithRetry = async (
+  octokit: ReturnType<typeof getOctokit>,
+  details: {
+    numberOfRetries: number;
+    trial: number;
+  } & PullRequestDetails,
+): Promise<void> => {
+  const { trial, numberOfRetries } = details;
+
   try {
-    await octokit.graphql(mutation, { commitHeadline, pullRequestId });
+    await merge(octokit, details);
   } catch (error) {
     logInfo(
       'An error ocurred while merging the Pull Request. This is usually ' +
@@ -40,5 +63,21 @@ export const merge = async (
     );
     /* eslint-disable-next-line @typescript-eslint/no-base-to-string */
     logDebug(`Original error: ${(error as Error).toString()}.`);
+
+    if (trial <= numberOfRetries) {
+      const nextRetryIn = trial ** EXPONENTIAL_BACKOFF * WAIT_TIME_SECONDS;
+
+      logInfo(`Retrying in ${nextRetryIn.toString()}...`);
+
+      await delay(nextRetryIn);
+
+      await mergeWithRetry(octokit, {
+        ...details,
+        numberOfRetries,
+        trial: trial + 1,
+      });
+    } else {
+      throw error;
+    }
   }
 };
diff --git a/src/eventHandlers/checkSuite/index.spec.ts b/src/eventHandlers/checkSuite/index.spec.ts
@@ -61,7 +61,7 @@ describe('check Suite event handler', (): void => {
       });
     nock('https://api.github.com').post('/graphql').reply(OK);
 
-    await checkSuiteHandle(octokit, 'dependabot-preview[bot]');
+    await checkSuiteHandle(octokit, 'dependabot-preview[bot]', 3);
 
     expect(warningSpy).not.toHaveBeenCalled();
   });
@@ -116,7 +116,7 @@ describe('check Suite event handler', (): void => {
       })
       .reply(OK);
 
-    await checkSuiteHandle(octokit, 'dependabot-preview[bot]');
+    await checkSuiteHandle(octokit, 'dependabot-preview[bot]', 3);
   });
 
   it('does not approve pull requests that are not mergeable', async (): Promise<
@@ -160,7 +160,7 @@ describe('check Suite event handler', (): void => {
         },
       });
 
-    await checkSuiteHandle(octokit, 'dependabot-preview[bot]');
+    await checkSuiteHandle(octokit, 'dependabot-preview[bot]', 3);
 
     expect(infoSpy).toHaveBeenCalledWith(
       'Pull request is not in a mergeable state: CONFLICTING.',
@@ -208,7 +208,7 @@ describe('check Suite event handler', (): void => {
         },
       });
 
-    await checkSuiteHandle(octokit, 'dependabot-preview[bot]');
+    await checkSuiteHandle(octokit, 'dependabot-preview[bot]', 3);
 
     expect(infoSpy).toHaveBeenCalledWith('Pull request is already merged.');
   });
@@ -254,7 +254,7 @@ describe('check Suite event handler', (): void => {
         },
       });
 
-    await checkSuiteHandle(octokit, 'dependabot-preview[bot]');
+    await checkSuiteHandle(octokit, 'dependabot-preview[bot]', 3);
 
     expect(infoSpy).toHaveBeenCalledWith(
       'Pull request cannot be merged cleanly. Current state: UNKNOWN.',
@@ -302,7 +302,7 @@ describe('check Suite event handler', (): void => {
         },
       });
 
-    await checkSuiteHandle(octokit, 'dependabot-preview[bot]');
+    await checkSuiteHandle(octokit, 'dependabot-preview[bot]', 3);
 
     expect(infoSpy).toHaveBeenCalledWith('Pull request is not open: CLOSED.');
   });
@@ -312,7 +312,7 @@ describe('check Suite event handler', (): void => {
   > => {
     expect.assertions(1);
 
-    await checkSuiteHandle(octokit, 'some-other-login');
+    await checkSuiteHandle(octokit, 'some-other-login', 3);
 
     expect(infoSpy).toHaveBeenCalledWith(
       'Pull request created by dependabot-preview[bot], not some-other-login, skipping.',
@@ -334,7 +334,7 @@ describe('check Suite event handler', (): void => {
         },
       });
 
-    await checkSuiteHandle(octokit, 'dependabot-preview[bot]');
+    await checkSuiteHandle(octokit, 'dependabot-preview[bot]', 3);
 
     expect(warningSpy).toHaveBeenCalled();
   });

diff --git a/src/eventHandlers/checkSuite/index.ts b/src/eventHandlers/checkSuite/index.ts
@@ -2,7 +2,7 @@
 
 import { context, getOctokit } from '@actions/github';
 
-import { merge } from '../../common/merge';
+import { mergeWithRetry } from '../../common/merge';
 import { findPullRequestInfo as findPullRequestInformation } from '../../graphql/queries';
 import {
   MergeableState,
@@ -91,6 +91,7 @@ const getPullRequestInformation = async (
 
 const tryMerge = async (
   octokit: ReturnType<typeof getOctokit>,
+  numberOfRetries: number,
   {
     commitMessageHeadline,
     mergeStateStatus,
@@ -122,17 +123,20 @@ const tryMerge = async (
   } else if (pullRequestState !== 'OPEN') {
     logInfo(`Pull request is not open: ${pullRequestState}.`);
   } else {
-    await merge(octokit, {
+    await mergeWithRetry(octokit, {
       commitHeadline: commitMessageHeadline,
+      numberOfRetries,
       pullRequestId,
       reviewEdge: reviewEdges[0],
+      trial: 1,
     });
   }
 };
 
 export const checkSuiteHandle = async (
   octokit: ReturnType<typeof getOctokit>,
   gitHubLogin: string,
+  numberOfReties: number,
 ): Promise<void> => {
   const pullRequests = context.payload.check_suite.pull_requests as Array<{
     number: number;
@@ -168,7 +172,7 @@ export const checkSuiteHandle = async (
         )}.`,
       );
 
-      await tryMerge(octokit, pullRequestInformation);
+      await tryMerge(octokit, numberOfReties, pullRequestInformation);
     }
   }
 };
diff --git a/src/eventHandlers/pullRequest/index.spec.ts b/src/eventHandlers/pullRequest/index.spec.ts
@@ -65,7 +65,7 @@ describe('pull request event handler', (): void => {
       });
     nock('https://api.github.com').post('/graphql').reply(OK);
 
-    await pullRequestHandle(octokit, 'dependabot-preview[bot]');
+    await pullRequestHandle(octokit, 'dependabot-preview[bot]', 3);
 
     expect(warningSpy).not.toHaveBeenCalled();
   });
@@ -77,7 +77,7 @@ describe('pull request event handler', (): void => {
       data: null,
     });
 
-    await pullRequestHandle(octokit, 'dependabot-preview[bot]');
+    await pullRequestHandle(octokit, 'dependabot-preview[bot]', 3);
   });
 
   it('does not approve an already approved pull request', async (): Promise<
@@ -129,6 +129,6 @@ describe('pull request event handler', (): void => {
       })
       .reply(OK);
 
-    await pullRequestHandle(octokit, 'dependabot-preview[bot]');
+    await pullRequestHandle(octokit, 'dependabot-preview[bot]', 3);
   });
 });
diff --git a/src/eventHandlers/pullRequest/index.ts b/src/eventHandlers/pullRequest/index.ts
@@ -1,6 +1,6 @@
 import { context, getOctokit } from '@actions/github';
 
-import { merge } from '../../common/merge';
+import { mergeWithRetry } from '../../common/merge';
 import { findPullRequestLastApprovedReview } from '../../graphql/queries';
 import { ReviewEdges } from '../../types';
 import { logInfo, logWarning } from '../../utilities/log';
@@ -52,6 +52,7 @@ const getPullRequestInformation = async (
 export const pullRequestHandle = async (
   octokit: ReturnType<typeof getOctokit>,
   gitHubLogin: string,
+  numberOfRetries: number,
 ): Promise<void> => {
   const { repository, pull_request: pullRequest } = context.payload;
 
@@ -86,10 +87,12 @@ export const pullRequestHandle = async (
       )}.`,
     );
 
-    await merge(octokit, {
+    await mergeWithRetry(octokit, {
       commitHeadline: pullRequest.title,
+      numberOfRetries,
       pullRequestId: pullRequest.node_id,
       reviewEdge: pullRequestInformation.reviewEdges[0],
+      trial: 1,
     });
   }
 };
diff --git a/src/eventHandlers/push/index.spec.ts b/src/eventHandlers/push/index.spec.ts
@@ -59,7 +59,7 @@ describe('push event handler', (): void => {
       });
     nock('https://api.github.com').post('/graphql').reply(OK);
 
-    await pushHandle(octokit, 'dependabot-preview[bot]');
+    await pushHandle(octokit, 'dependabot-preview[bot]', 3);
 
     expect(warningSpy).not.toHaveBeenCalled();
   });
@@ -106,7 +106,7 @@ describe('push event handler', (): void => {
       })
       .reply(OK);
 
-    await pushHandle(octokit, 'dependabot-preview[bot]');
+    await pushHandle(octokit, 'dependabot-preview[bot]', 3);
   });
 
   it('does not approve pull requests that are not mergeable', async (): Promise<
@@ -142,7 +142,7 @@ describe('push event handler', (): void => {
         },
       });
 
-    await pushHandle(octokit, 'dependabot-preview[bot]');
+    await pushHandle(octokit, 'dependabot-preview[bot]', 3);
 
     expect(infoSpy).toHaveBeenCalledWith(
       'Pull request is not in a mergeable state: CONFLICTING.',
@@ -182,7 +182,7 @@ describe('push event handler', (): void => {
         },
       });
 
-    await pushHandle(octokit, 'dependabot-preview[bot]');
+    await pushHandle(octokit, 'dependabot-preview[bot]', 3);
 
     expect(infoSpy).toHaveBeenCalledWith('Pull request is already merged.');
   });
@@ -220,7 +220,7 @@ describe('push event handler', (): void => {
         },
       });
 
-    await pushHandle(octokit, 'dependabot-preview[bot]');
+    await pushHandle(octokit, 'dependabot-preview[bot]', 3);
 
     expect(infoSpy).toHaveBeenCalledWith('Pull request is not open: CLOSED.');
   });
@@ -230,7 +230,7 @@ describe('push event handler', (): void => {
   > => {
     expect.assertions(1);
 
-    await pushHandle(octokit, 'some-other-login');
+    await pushHandle(octokit, 'some-other-login', 3);
 
     expect(infoSpy).toHaveBeenCalledWith(
       'Pull request created by dependabot-preview[bot], not some-other-login, skipping.',
@@ -254,7 +254,7 @@ describe('push event handler', (): void => {
         },
       });
 
-    await pushHandle(octokit, 'dependabot-preview[bot]');
+    await pushHandle(octokit, 'dependabot-preview[bot]', 3);
 
     expect(warningSpy).toHaveBeenCalled();
   });

diff --git a/src/eventHandlers/push/index.ts b/src/eventHandlers/push/index.ts
@@ -1,6 +1,6 @@
 import { context, getOctokit } from '@actions/github';
 
-import { merge } from '../../common/merge';
+import { mergeWithRetry } from '../../common/merge';
 import { findPullRequestInfoAndReviews as findPullRequestInformationAndReviews } from '../../graphql/queries';
 import {
   CommitMessageHeadlineGroup,
@@ -78,6 +78,7 @@ const getPullRequestInformation = async (
 
 const tryMerge = async (
   octokit: ReturnType<typeof getOctokit>,
+  numberOfRetries: number,
   {
     commitMessageHeadline,
     mergeableState,
@@ -94,17 +95,20 @@ const tryMerge = async (
   } else if (pullRequestState !== 'OPEN') {
     logInfo(`Pull request is not open: ${pullRequestState}.`);
   } else {
-    await merge(octokit, {
+    await mergeWithRetry(octokit, {
       commitHeadline: commitMessageHeadline,
+      numberOfRetries,
       pullRequestId,
       reviewEdge: reviewEdges[0],
+      trial: 1,
     });
   }
 };
 
 export const pushHandle = async (
   octokit: ReturnType<typeof getOctokit>,
   gitHubLogin: string,
+  numberOfRetries: number,
 ): Promise<void> => {
   if (context.payload.pusher.name !== gitHubLogin) {
     logInfo(
@@ -131,7 +135,7 @@ export const pushHandle = async (
       )}.`,
     );
 
-    await tryMerge(octokit, {
+    await tryMerge(octokit, numberOfRetries, {
       ...pullRequestInformation,
       commitMessageHeadline: getCommitMessageHeadline(),
     });