Update branch option before auto-merge

.eslintignore

@@ -1,3 +1,4 @@
 node_modules
 dist
 .git
+src/github/graphql/*

.gitignore

@@ -9,3 +9,5 @@
 !.vscode/extensions.json
 !.vscode/settings.json
 .idea
+
+src/github/graphql/*.ts

Dockerfile

@@ -4,10 +4,12 @@ WORKDIR /action
 
 COPY package.json yarn.lock ./
 
-RUN yarn install --frozen-lockfile
+RUN yarn install --frozen-lockfile --ignore-scripts
 
 COPY . .
 
+RUN yarn run postinstall
+
 RUN yarn run build
 
 FROM node:20-slim

README.md

@@ -53,6 +53,8 @@ You can find all the inputs in [the action file](./action.yml), but let's walk t
   - An [unstable PR](https://docs.github.com/en/graphql/reference/enums#mergestatestatus) is a PR that can be merged, but a *non required status check* is failing.
     - This is only relevant once the PR can be merged. GitHub's auto-merge always merges unstable PRs
   - **Optional**: Defaults to `true`
+- `UPDATE_BEFORE_MERGE`: If the bot should try to update the PR to be up to date before enabling auto-merge
+  - **Optional**: Defaults to false
 
 ## Usage
 

action.yml

@@ -21,10 +21,13 @@ inputs:
   ALLOW_UNSTABLE:
     required: false
     description: If unstable, ready to merge, PRs can be merged. Defaults to true
+  UPDATE_BEFORE_MERGE:
+    required: false
+    description: If the bot should update the Pull Request Branch before enabling auto-merge
 outputs:
   repo:
     description: 'The name of the repo in owner/repo pattern'
 
 runs:
   using: 'docker'
-  image: 'docker://ghcr.io/paritytech/auto-merge-bot/action:1.0.1'
+  image: 'docker://ghcr.io/paritytech/auto-merge-bot/action:1.1.0'

codegen.ts

@@ -0,0 +1,15 @@
+
+import type { CodegenConfig } from '@graphql-codegen/cli';
+
+const config: CodegenConfig = {
+  overwrite: true,
+  schema: "./node_modules/@octokit/graphql-schema/schema.graphql",
+  documents: "src/**/*.gql",
+  generates: {
+    "src/github/graphql/index.ts": {
+      plugins: ["typescript", "typescript-operations"],
+    }
+  }
+};
+
+export default config;

package.json

@@ -1,14 +1,17 @@
 {
   "name": "auto-merge-bot",
-  "version": "1.0.1",
+  "version": "1.1.0",
   "description": "Bot which enables or disable auto-merge",
   "main": "src/index.ts",
   "scripts": {
     "start": "node dist",
     "build": "ncc build --license LICENSE",
     "test": "jest",
     "fix": "eslint --fix 'src/**/*'",
-    "lint": "eslint 'src/**/*'"
+    "lint": "eslint 'src/**/*'",
+    "codegen": "graphql-codegen --config codegen.ts",
+    "copy": "node scripts/copy-files.js",
+    "postinstall": "npm-run-all codegen copy"
   },
   "repository": {
     "type": "git",
@@ -25,15 +28,20 @@
     "@actions/github": "^6.0.0",
     "@octokit/graphql": "^8.0.1",
     "@octokit/graphql-schema": "^14.58.0",
-    "@octokit/webhooks-types": "^7.3.2"
+    "@octokit/webhooks-types": "^7.4.0",
+    "graphql": "^16.8.1"
   },
   "devDependencies": {
     "@eng-automation/js-style": "^2.3.0",
+    "@graphql-codegen/cli": "5.0.2",
+    "@graphql-codegen/typescript": "4.0.6",
+    "@graphql-codegen/typescript-resolvers": "^4.0.6",
     "@types/jest": "^29.5.12",
     "@vercel/ncc": "^0.38.1",
     "jest": "^29.7.0",
     "jest-mock-extended": "^3.0.5",
+    "npm-run-all": "^4.1.5",
     "ts-jest": "^29.1.2",
-    "typescript": "^5.3.3"
+    "typescript": "^5.4.3"
   }
 }

scripts/copy-files.js

@@ -0,0 +1,24 @@
+const { readdirSync, writeFileSync, readFileSync } = require("fs");
+
+const files = readdirSync("src/github/graphql/");
+
+/**
+ * Copy a file and replace it's extension
+ * @param {string} fileName Name of the file to copy
+ * @param {string} extension New extension to put
+ */
+const copyFile = (fileName, extension) => {
+  console.log("Copying content of %s into a .ts file", fileName);
+  const content = readFileSync(fileName);
+  const oldExtension = fileName.split(".").pop();
+  writeFileSync(
+    fileName.replace(oldExtension, extension),
+    `// Generated from ${fileName}\nexport default \`${content}\`;`,
+  );
+};
+
+for (const file of files) {
+  if (file.endsWith(".gql")) {
+    copyFile(`src/github/graphql/${file}`, "ts");
+  }
+}

src/bot.ts

@@ -30,6 +30,7 @@ export class Bot {
     private readonly logger: ActionLogger,
     private readonly commentsApi: CommentsApi,
     private readonly allowlistedUsers: string[],
+    private readonly updateBeforeMerge: boolean,
     private readonly actionUrl: string,
   ) {}
 
@@ -94,6 +95,9 @@ export class Bot {
         // Simply `/merge`
         case undefined:
           await this.commentsApi.reactToComment(this.comment.id, "+1");
+          if (this.updateBeforeMerge) {
+            await merger.updatePR();
+          }
           await merger.enableAutoMerge();
           await this.commentsApi.comment(
             "Enabled `auto-merge` in Pull Request\n\n" + detailCommands,

src/github/graphql/DisableAutoMerge.gql

@@ -0,0 +1,5 @@
+mutation DisableAutoMerge($prId: ID!) {
+    disablePullRequestAutoMerge(input: {pullRequestId: $prId}) {
+        clientMutationId
+    }
+}

src/github/graphql/EnableAutoMerge.gql

@@ -0,0 +1,5 @@
+mutation EnableAutoMerge($prId: ID!, $mergeMethod: PullRequestMergeMethod!) {
+    enablePullRequestAutoMerge(input: {pullRequestId: $prId, mergeMethod: $mergeMethod}) {
+        clientMutationId
+    }
+}

src/github/graphql/MergePullRequest.gql

@@ -0,0 +1,5 @@
+mutation MergePullRequest($prId: ID!, $mergeMethod: PullRequestMergeMethod!) {
+  mergePullRequest(input: {pullRequestId: $prId, mergeMethod: $mergeMethod}) {
+      clientMutationId
+  }
+}

src/github/graphql/UpdatePullRequest.gql

@@ -0,0 +1,10 @@
+mutation UpdatePullRequestBranch($prId: ID!) {
+  updatePullRequestBranch(input: {pullRequestId: $prId}) {
+    clientMutationId
+    pullRequest {
+      title
+      number
+      headRefName
+    }
+  }
+}

src/github/merger.ts

@@ -1,38 +1,29 @@
 import { graphql } from "@octokit/graphql";
-import { PullRequestMergeMethod } from "@octokit/graphql-schema";
+import { RequestParameters } from "@octokit/graphql/dist-types/types";
 
+import {
+  DisableAutoMergeMutation,
+  DisableAutoMergeMutationVariables,
+  EnableAutoMergeMutation,
+  EnableAutoMergeMutationVariables,
+  MergePullRequestMutation,
+  MergePullRequestMutationVariables,
+  PullRequestMergeMethod,
+  UpdatePullRequestBranchMutation,
+  UpdatePullRequestBranchMutationVariables,
+} from "./graphql";
+import DISABLE_AUTO_MERGE from "./graphql/DisableAutoMerge";
+import ENABLE_AUTO_MERGE from "./graphql/EnableAutoMerge";
+import MERGE_PULL_REQUEST from "./graphql/MergePullRequest";
+import UPDATE_PULL_REQUEST from "./graphql/UpdatePullRequest";
 import { ActionLogger } from "./types";
 
-// https://docs.github.com/en/graphql/reference/mutations#enablepullrequestautomerge
-export const ENABLE_AUTO_MERGE = `
-mutation($prId: ID!, $mergeMethod: PullRequestMergeMethod!) {
-    enablePullRequestAutoMerge(input: {pullRequestId: $prId, mergeMethod: $mergeMethod}) {
-        clientMutationId
-    }
-}`;
-
-// https://docs.github.com/en/graphql/reference/mutations#disablepullrequestautomerge
-export const DISABLE_AUTO_MERGE = `
-mutation($prId: ID!) {
-    disablePullRequestAutoMerge(input: {pullRequestId: $prId}) {
-        clientMutationId
-    }
-}`;
-
-// https://docs.github.com/en/graphql/reference/mutations#mergepullrequest
-export const MERGE_PULL_REQUEST = `
-mutation($prId: ID!, $mergeMethod: PullRequestMergeMethod!) {
-  mergePullRequest(input: {pullRequestId: $prId, mergeMethod: $mergeMethod}) {
-      clientMutationId
-  }
-}`;
-
 export type MergeMethod = "SQUASH" | "MERGE" | "REBASE";
 
 export class Merger {
   constructor(
     private readonly nodeId: string,
-    private readonly gql: typeof graphql,
+    private readonly gqlApi: typeof graphql,
     private readonly logger: ActionLogger,
     private readonly mergeMethod: PullRequestMergeMethod,
     private readonly allowUnstable: boolean = false,
@@ -55,24 +46,45 @@ export class Merger {
     return false;
   }
 
-  async enableAutoMerge(): Promise<void> {
+  async updatePR(): Promise<void> {
+    this.logger.info("Updating branch before enabling auto-merge");
     try {
-      await this.gql<{
-        enablePullRequestAutoMerge: { clientMutationId: unknown };
-      }>(ENABLE_AUTO_MERGE, {
+      const update = await this.gql<
+        UpdatePullRequestBranchMutationVariables,
+        UpdatePullRequestBranchMutation
+      >(UPDATE_PULL_REQUEST, {
         prId: this.nodeId,
-        mergeMethod: this.mergeMethod,
       });
+      this.logger.info(
+        `Succesfully updated ${
+          update.updatePullRequestBranch?.pullRequest?.headRefName ?? "unknown"
+        } branch`,
+      );
+    } catch (err) {
+      this.logger.warn(err as Error);
+    }
+  }
+
+  async enableAutoMerge(): Promise<void> {
+    try {
+      await this.gql<EnableAutoMergeMutationVariables, EnableAutoMergeMutation>(
+        ENABLE_AUTO_MERGE,
+        {
+          prId: this.nodeId,
+          mergeMethod: this.mergeMethod as PullRequestMergeMethod,
+        },
+      );
       this.logger.info("Succesfully enabled auto-merge");
     } catch (error) {
       this.logger.warn(error as Error);
       if (error instanceof Error && this.errorPermitsToMerge(error)) {
         this.logger.warn(
           "Pull Request is ready to merge. Running merge command instead",
         );
-        await this.gql<{
-          mergePullRequest: { clientMutationId: unknown };
-        }>(MERGE_PULL_REQUEST, {
+        await this.gql<
+          MergePullRequestMutationVariables,
+          MergePullRequestMutation
+        >(MERGE_PULL_REQUEST, {
           prId: this.nodeId,
           mergeMethod: this.mergeMethod,
         });
@@ -84,11 +96,17 @@ export class Merger {
   }
 
   async disableAutoMerge(): Promise<void> {
-    await this.gql<{
-      disablePullRequestAutoMerge: { clientMutationId: unknown };
-    }>(DISABLE_AUTO_MERGE, {
-      prId: this.nodeId,
-    });
+    await this.gql<DisableAutoMergeMutationVariables, DisableAutoMergeMutation>(
+      DISABLE_AUTO_MERGE,
+      { prId: this.nodeId },
+    );
     this.logger.info("Succesfully disabled auto-merge");
   }
+
+  async gql<Params extends RequestParameters, Output>(
+    query: string,
+    params: Params,
+  ): Promise<Output> {
+    return await this.gqlApi<Output>(query, params);
+  }
 }

src/index.ts

@@ -2,11 +2,11 @@ import { getInput, setFailed, setOutput } from "@actions/core";
 import { context, getOctokit } from "@actions/github";
 import { Context } from "@actions/github/lib/context";
 import { graphql } from "@octokit/graphql/dist-types/types";
-import { PullRequestMergeMethod } from "@octokit/graphql-schema";
 import { Issue, IssueComment } from "@octokit/webhooks-types";
 
 import { Bot } from "./bot";
 import { CommentsApi } from "./github/comments";
+import { PullRequestMergeMethod } from "./github/graphql";
 import { Merger } from "./github/merger";
 import { generateCoreLogger, getallowlistedUsers } from "./util";
 
@@ -59,6 +59,9 @@ const getAllowUnstable = (): boolean => {
 
 const silentMode = getInput("SILENT", { required: false }) === "true";
 
+const getupdateBeforeMerge = (): boolean =>
+  getInput("UPDATE_BEFORE_MERGE", { required: false }) === "true";
+
 logger.info(
   `Silent mode is ${
     silentMode ? "enabled" : "disabled. Bot will comment actions"
@@ -87,11 +90,12 @@ if (context.payload.comment) {
   }) as graphql;
   const mergeMethod = getMergeMethod();
   const unstableAllowed = getAllowUnstable();
+  const updateBeforeMerge = getupdateBeforeMerge();
   const merger = new Merger(
     issue.node_id,
     gql,
     logger,
-    mergeMethod,
+    mergeMethod as PullRequestMergeMethod,
     unstableAllowed,
   );
   const bot = new Bot(
@@ -100,6 +104,7 @@ if (context.payload.comment) {
     logger,
     commentsApi,
     allowlistedUsers,
+    updateBeforeMerge,
     actionUrl,
   );
   bot

src/test/queries.test.ts

@@ -1,10 +1,9 @@
 import { validate } from "@octokit/graphql-schema";
 
-import {
-  DISABLE_AUTO_MERGE,
-  ENABLE_AUTO_MERGE,
-  MERGE_PULL_REQUEST,
-} from "../github/merger";
+import DISABLE_AUTO_MERGE from "../github/graphql/DisableAutoMerge";
+import ENABLE_AUTO_MERGE from "../github/graphql/EnableAutoMerge";
+import MERGE_PULL_REQUEST from "../github/graphql/MergePullRequest";
+import UPDATE_PULL_REQUEST from "../github/graphql/UpdatePullRequest";
 
 describe("Schemas", () => {
   test("ENABLE_AUTO_MERGE", () => {
@@ -18,4 +17,8 @@ describe("Schemas", () => {
   test("MERGE_PULL_REQUEST", () => {
     expect(validate(MERGE_PULL_REQUEST)).toEqual([]);
   });
+
+  test("UPDATE_PULL_REQUEST", () => {
+    expect(validate(UPDATE_PULL_REQUEST)).toEqual([]);
+  });
 });

tsconfig.json

@@ -10,5 +10,6 @@
     },
     "exclude": [
         "node_modules",
+        "codegen.ts"
     ]
 }