feat: enable GitHub API request throttling

It implements best practices for using the GitHub API as described in
https://developer.github.com/v3/guides/best-practices-for-integrators/#dealing-with-abuse-rate-limits

When the primary rate limit is hit, it will log a warning and wait before
trying the API endpoint one more time before failing.

package.json

@@ -32,6 +32,7 @@
     "@actions/core": "^1.10.1",
     "@actions/github": "^6.0.0",
     "@octokit/core": "^5.0.1",
+    "@octokit/plugin-throttling": "^8.1.3",
     "@octokit/rest": "^20.0.2",
     "@octokit/types": "^12.4.0",
     "testing-farm": "^1.5.1",

src/main.ts

@@ -1,19 +1,17 @@
 import { getBooleanInput, getInput, setFailed } from '@actions/core';
 import { context } from '@actions/github';
-import { Octokit } from '@octokit/core';
 
 import '@total-typescript/ts-reset';
 
 import action from './action';
 import { TFError } from './error';
+import { getOctokit } from './octokit';
 import { PullRequest } from './pull-request';
 
 let pr: PullRequest | undefined = undefined;
 
 try {
-  const octokit = new Octokit({
-    auth: getInput('github_token', { required: true }),
-  });
+  const octokit = getOctokit(getInput('github_token', { required: true }));
 
   pr = await PullRequest.initialize(context.issue.number, octokit);
 

src/octokit.ts

@@ -0,0 +1,32 @@
+import { info, warning } from '@actions/core';
+import { Octokit } from '@octokit/core';
+import { throttling } from '@octokit/plugin-throttling';
+
+const CustomOctokit = Octokit.plugin(throttling);
+
+export type CustomOctokit = InstanceType<typeof CustomOctokit>;
+
+export function getOctokit(token: string) {
+  return new CustomOctokit({
+    auth: token,
+    throttle: {
+      onRateLimit: (retryAfter, options, _octokit, retryCount) => {
+        warning(
+          `Request quota exhausted for request ${options.method} ${options.url}`
+        );
+
+        // Retry once after hitting a rate limit error, then give up
+        if (retryCount < 1) {
+          info(`Retrying after ${retryAfter} seconds!`);
+          return true;
+        }
+      },
+      onSecondaryRateLimit: (_retryAfter, options) => {
+        // When a secondary rate limit is hit, don't retry
+        warning(
+          `SecondaryRateLimit detected for request ${options.method} ${options.url}`
+        );
+      },
+    },
+  });
+}

src/pull-request.ts

@@ -1,8 +1,9 @@
 import { debug, getInput } from '@actions/core';
 import { context } from '@actions/github';
-import { Octokit } from '@octokit/core';
 import { Endpoints } from '@octokit/types';
 
+import { CustomOctokit } from './octokit';
+
 /**
  * Class for holding information about a Pull Request and interacting with it via the GitHub API.
  */
@@ -16,7 +17,7 @@ export class PullRequest {
   private constructor(
     readonly number: number,
     readonly sha: string,
-    readonly octokit: Octokit
+    readonly octokit: CustomOctokit
   ) {}
 
   /**
@@ -72,7 +73,7 @@ export class PullRequest {
    */
   static async initialize(
     number: number,
-    octokit: Octokit
+    octokit: CustomOctokit
   ): Promise<PullRequest> {
     const { data } = await octokit.request(
       'GET /repos/{owner}/{repo}/pulls/{pull_number}',

yarn.lock

@@ -518,6 +518,18 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@octokit/plugin-throttling@npm:^8.1.3":
+  version: 8.1.3
+  resolution: "@octokit/plugin-throttling@npm:8.1.3"
+  dependencies:
+    "@octokit/types": ^12.2.0
+    bottleneck: ^2.15.3
+  peerDependencies:
+    "@octokit/core": ^5.0.0
+  checksum: 98963ef2eab825015702b1ca1ef4ccbda0c009242e93001144e51014d3b53d3ecb1282b67488680c7f5f4e805d0c3af4020ad673079fff92c6353f04903a9a64
+  languageName: node
+  linkType: hard
+
 "@octokit/request-error@npm:^5.0.0":
   version: 5.0.1
   resolution: "@octokit/request-error@npm:5.0.1"
@@ -1171,6 +1183,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"bottleneck@npm:^2.15.3":
+  version: 2.19.5
+  resolution: "bottleneck@npm:2.19.5"
+  checksum: c5eef1bbea12cef1f1405e7306e7d24860568b0f7ac5eeab706a86762b3fc65ef6d1c641c8a166e4db90f412fc5c948fc5ce8008a8cd3d28c7212ef9c3482bda
+  languageName: node
+  linkType: hard
+
 "brace-expansion@npm:^1.1.7":
   version: 1.1.11
   resolution: "brace-expansion@npm:1.1.11"
@@ -3035,6 +3054,7 @@ __metadata:
     "@actions/core": ^1.10.1
     "@actions/github": ^6.0.0
     "@octokit/core": ^5.0.1
+    "@octokit/plugin-throttling": ^8.1.3
     "@octokit/rest": ^20.0.2
     "@octokit/types": ^12.4.0
     "@total-typescript/ts-reset": ^0.5.1