Allow configuring title (#35)

action.yml

@@ -2,12 +2,16 @@ name: Backporting
 author: Thibault Derousseaux <[email protected]>
 description: Automatically backport PRs to other branches by simply labeling them.
 inputs:
+  add_labels:
+    description: Comma separated list of labels to add to the backport PR.
+    required: false
   github_token:
     description: Token for the GitHub API.
     required: true
-  add_labels:
-    description: A comma separated list of labels to add to the backport PR.
+  title_template:
+    description: Template for the title of the backport PR.
     required: false
+    default: "[Backport {{base}}] {{originalTitle}}"
 runs:
   using: node12
   main: dist/index.js

package.json

@@ -19,6 +19,7 @@
     "@actions/exec": "^1.0.1",
     "@actions/github": "^1.1.0",
     "@octokit/webhooks": "^6.3.0",
+    "@types/lodash.escaperegexp": "^4.1.6",
     "@types/node": "^10.0.3",
     "@types/promise-retry": "^1.1.1",
     "@typescript-eslint/eslint-plugin": "^2.3.1",
@@ -33,6 +34,7 @@
     "eslint-plugin-sort-destructure-keys": "^1.3.3",
     "eslint-plugin-typescript-sort-keys": "^0.4.0",
     "eslint-plugin-unicorn": "^12.0.1",
+    "lodash.escaperegexp": "^4.1.2",
     "prettier": "^1.18.2",
     "typescript": "^3.6.3"
   }

src/backport.ts

@@ -2,6 +2,7 @@ import { error as logError, group, warning, info } from "@actions/core";
 import { exec } from "@actions/exec";
 import { GitHub } from "@actions/github";
 import { WebhookPayloadPullRequest } from "@octokit/webhooks";
+import escapeRegExp from "lodash.escaperegexp";
 
 const labelRegExp = /^backport ([^ ]+)(?: ([^ ]+))?$/;
 
@@ -183,10 +184,12 @@ const backport = async ({
       owner: { login: owner },
     },
   },
+  titleTemplate,
   token,
 }: {
   labelsToAdd: string[];
   payload: WebhookPayloadPullRequest;
+  titleTemplate: string;
   token: string;
 }) => {
   if (!merged) {
@@ -226,7 +229,15 @@ const backport = async ({
 
   for (const [base, head] of Object.entries(backportBaseToHead)) {
     const body = `Backport ${commitToBackport} from #${pullRequestNumber}`;
-    const title = `[Backport ${base}] ${originalTitle}`;
+    const titleVariables = {
+      base,
+      originalTitle,
+    };
+    const title = Object.entries(titleVariables).reduce(
+      (variable, [name, value]) =>
+        variable.replace(new RegExp(escapeRegExp(`{{${name}}}`), "g"), value),
+      titleTemplate,
+    );
     await group(`Backporting to ${base} on ${head}`, async () => {
       try {
         await backportOnce({

src/index.ts

@@ -8,12 +8,14 @@ import { getLabelsToAdd } from "./get-labels-to-add";
 const run = async () => {
   try {
     const token = getInput("github_token", { required: true });
+    const titleTemplate = getInput("title_template");
     debug(JSON.stringify(context, null, 2));
     const labelsInput = getInput("labels");
     const labelsToAdd = getLabelsToAdd(labelsInput);
     await backport({
       labelsToAdd,
       payload: context.payload as WebhookPayloadPullRequest,
+      titleTemplate,
       token,
     });
   } catch (error) {

yarn.lock

@@ -123,6 +123,18 @@
   resolved "https://registry.yarnpkg.com/@types/json5/-/json5-0.0.29.tgz#ee28707ae94e11d2b827bcbe5270bcea7f3e71ee"
   integrity sha1-7ihweulOEdK4J7y+UnC86n8+ce4=
 
+"@types/lodash.escaperegexp@^4.1.6":
+  version "4.1.6"
+  resolved "https://registry.yarnpkg.com/@types/lodash.escaperegexp/-/lodash.escaperegexp-4.1.6.tgz#3e2326aa33e95b2f3801de027f04a4f7aba2af4f"
+  integrity sha512-uENiqxLlqh6RzeE1cC6Z2gHqakToN9vKlTVCFkSVjAfeMeh2fY0916tHwJHeeKs28qB/hGYvKuampGYH5QDVCw==
+  dependencies:
+    "@types/lodash" "*"
+
+"@types/lodash@*":
+  version "4.14.149"
+  resolved "https://registry.yarnpkg.com/@types/lodash/-/lodash-4.14.149.tgz#1342d63d948c6062838fbf961012f74d4e638440"
+  integrity sha512-ijGqzZt/b7BfzcK9vTrS6MFljQRPn5BFWOx8oE0GYxribu6uV+aA9zZuXI1zc/etK9E8nrgdoF2+LgUw7+9tJQ==
+
 "@types/node@>= 8":
   version "12.12.8"
   resolved "https://registry.yarnpkg.com/@types/node/-/node-12.12.8.tgz#dab418655af39ce2fa99286a0bed21ef8072ac9d"
@@ -1065,6 +1077,11 @@ lodash.defaultsdeep@^4.6.1:
   resolved "https://registry.yarnpkg.com/lodash.defaultsdeep/-/lodash.defaultsdeep-4.6.1.tgz#512e9bd721d272d94e3d3a63653fa17516741ca6"
   integrity sha512-3j8wdDzYuWO3lM3Reg03MuQR957t287Rpcxp1njpEa8oDrikb+FwGdW3n+FELh/A6qib6yPit0j/pv9G/yeAqA==
 
+lodash.escaperegexp@^4.1.2:
+  version "4.1.2"
+  resolved "https://registry.yarnpkg.com/lodash.escaperegexp/-/lodash.escaperegexp-4.1.2.tgz#64762c48618082518ac3df4ccf5d5886dae20347"
+  integrity sha1-ZHYsSGGAglGKw99Mz11YhtriA0c=
+
 lodash.get@^4.4.2:
   version "4.4.2"
   resolved "https://registry.yarnpkg.com/lodash.get/-/lodash.get-4.4.2.tgz#2d177f652fa31e939b4438d5341499dfa3825e99"