feat!: Convert to ESM and drop yargs

eslint.config.js

@@ -1,3 +1,3 @@
-var gulpConfig = require("eslint-config-gulp");
+import gulpConfig from "eslint-config-gulp";
 
-module.exports = [...gulpConfig.default];
+export default [...gulpConfig];

index.js

@@ -1,76 +1,86 @@
 #!/usr/bin/env node
 
-const fs = require(`fs`);
-const path = require(`path`);
-const yaml = require(`js-yaml`);
-const yargs = require(`yargs`);
-const { Semver } = require(`sver`);
-const remoteGitTags = require(`remote-git-tags`);
-const boilerplateUpdate = require(`boilerplate-update`);
-const { execSync } = require("child_process");
+import fs from "node:fs";
+import path from "node:path";
+import { execSync } from "node:child_process";
+import { parseArgs } from "node:util";
 
-const REMOTE_URL = `https://github.com/gulpjs/.boilerplate`;
+import yaml from "js-yaml";
+import { Semver } from "sver";
+import remoteGitTags from "remote-git-tags";
+import boilerplateUpdate from "boilerplate-update";
+
+import packageJSON from "./package.json" with { type: "json" };
+
+const REMOTE_URL = "https://github.com/gulpjs/.boilerplate";
 
 function trimV(tag) {
-  return tag[0] === `v` ? tag.slice(1) : tag;
+  return tag[0] === "v" ? tag.slice(1) : tag;
 }
 
 // This function makes assumption about the layout of .boilerplate
 // at specific tags to determine a starting point for updating
-function guessStartTag() {
+async function guessStartTag() {
   // `.jscsrc` was used before we added Azure Pipelines
-  if (fs.existsSync(`.jscsrc`)) {
-    return `1.0.0`;
+  if (fs.existsSync(".jscsrc")) {
+    return "1.0.0";
   }
 
   // `.ci` was added to support Azure Pipelines
-  if (fs.existsSync(`.ci`)) {
-    return `2.0.0`;
+  if (fs.existsSync(".ci")) {
+    return "2.0.0";
   }
 
   // If we are in the 3.x release stream, tiny changes were made to the workflow.yml
   try {
-    const devFile = fs.readFileSync(`.github/workflows/dev.yml`, `utf-8`);
+    const devFile = fs.readFileSync(".github/workflows/dev.yml", "utf-8");
     const workflow = yaml.safeLoad(devFile);
 
     // We started 3.0.0 with `on: [push, pull_request]` but quickly changed
     // to avoid running the workflow on pushing tags
     if (Array.isArray(workflow.on)) {
-      return `3.0.0`;
+      return "3.0.0";
     }
 
-    // In 3.0.1, we didn`t check that the event was a push and that failed PRs
-    if (!workflow.jobs.prettier.if) {
-      return `3.0.1`;
+    // In 3.0.1, we didn't check that the event was a push and that failed PRs
+    if (workflow.jobs.prettier && !workflow.jobs.prettier.if) {
+      return "3.0.1";
     }
 
-    const pkg = require(path.join(process.cwd(), `package.json`));
+    const { default: pkg } = await import(
+      path.join(process.cwd(), "package.json"),
+      {
+        with: { type: "json" },
+      }
+    );
 
     // In 3.0.2, we updated the node version in package.json but forgot to remove some unused files
-    if (pkg.engines.node === `>=10.13.0`) {
-      const hasEslintignore = fs.existsSync(`.eslintignore`);
+    if (pkg.engines.node === ">=10.13.0") {
+      const hasEslintignore = fs.existsSync(".eslintignore");
 
       // We forgot to remove .eslintignore and some other files so we check for that
       if (hasEslintignore) {
-        return `3.0.2`;
+        return "3.0.2";
       }
     }
 
-    const releaseWorkflow = fs.existsSync(`.github/workflows/release.yml`);
+    const hasReleaseWorkflow = fs.existsSync(".github/workflows/release.yml");
     // In 3.1.0, we add the release.yml workflow file
-    if (!releaseWorkflow) {
-      return `3.0.3`;
+    if (!hasReleaseWorkflow) {
+      return "3.0.3";
     }
 
-    if (releaseWorkflow) {
-      return `3.1.0`;
+    const hasNpmrc = fs.existsSync(".npmrc");
+    if (hasReleaseWorkflow && hasNpmrc) {
+      return "3.1.0";
     }
 
     // 4.0.0 had a bug with repository metadata in package.json
-    return `4.0.1`;
+    return "4.0.1";
   } catch (err) {
+    console.error(err);
     // Always fallback to 1.0.0
-    return `1.0.0`;
+    return "1.0.0";
   }
 }
 
@@ -88,31 +98,46 @@ async function guessEndTag() {
   return versions.sort(Semver.compare).pop();
 }
 
-function opts(yargs) {
-  yargs.option(`start-tag`, {
-    alias: `s`,
-    describe: `Git tag of starting template (guessed if empty)`,
-    type: `string`,
-  });
-
-  yargs.option(`end-tag`, {
-    alias: `e`,
-    describe: `Git tag of ending template (guessed if empty)`,
-    type: `string`,
-  });
-}
-
-async function guessTags(argv) {
-  let startTag = argv.startTag;
+const options = {
+  help: {
+    type: "boolean",
+    short: "h",
+    describe: "Show help",
+    spacing: 5,
+  },
+  version: {
+    type: "boolean",
+    short: "v",
+    describe: "Show version number",
+    spacing: 2,
+  },
+  "start-tag": {
+    type: "string",
+    short: "s",
+    describe: "Git tag of starting template (guessed if empty)",
+    spacing: 0,
+  },
+  "end-tag": {
+    type: "string",
+    short: "s",
+    describe: "Git tag of ending template (guessed if empty)",
+    spacing: 2,
+  },
+};
+
+async function guessTags(values) {
+  let startTag = values["start-tag"];
   if (!startTag) {
-    startTag = guessStartTag();
+    startTag = await guessStartTag();
+    console.log(`Guessed start-tag: ${startTag}`);
   } else {
     startTag = trimV(startTag);
   }
 
-  let endTag = argv.endTag;
+  let endTag = values["end-tag"];
   if (!endTag) {
     endTag = await guessEndTag();
+    console.log(`Guessed end-tag: ${endTag}`);
   } else {
     endTag = trimV(endTag);
   }
@@ -123,19 +148,49 @@ async function guessTags(argv) {
   };
 }
 
-async function run(argv) {
-  if (!argv.startTag) {
-    return Promise.reject(`--start-tag is required & couldn't be guessed`);
+async function run(values) {
+  if (values.help) {
+    let help = `update-template
+
+  Update a gulp repository to our template.
+
+  Options:`;
+    for (const [flag, config] of Object.entries(options)) {
+      const leadingSpaces = Array.from(Array(config.spacing), () => " ").join(
+        "",
+      );
+      const trailingSpaces = config.type === "boolean" ? "" : " ";
+      help += "\n";
+      help += `  --${flag}, -${config.short} ${leadingSpaces}[${config.type}]${trailingSpaces} ${config.describe}`;
+    }
+    console.log(help);
+    return;
   }
 
-  if (!argv.endTag) {
-    return Promise.reject(`--end-tag is required & couldn't be guessed`);
+  if (values.version) {
+    console.log(packageJSON.version);
+    return;
+  }
+
+  const { startTag, endTag } = await guessTags(values);
+
+  if (!startTag) {
+    return Promise.reject("--start-tag is required & couldn't be guessed");
+  }
+
+  if (!endTag) {
+    return Promise.reject("--end-tag is required & couldn't be guessed");
+  }
+
+  if (startTag === endTag) {
+    console.log(`Tags match (${startTag}), nothing to apply`);
+    return;
   }
 
   var { promise: boilerplateUpdatePromise } = await boilerplateUpdate({
     remoteUrl: REMOTE_URL,
-    startVersion: argv.startTag,
-    endVersion: argv.endTag,
+    startVersion: startTag,
+    endVersion: endTag,
     resolveConflicts: {
       stdio: "inherit",
     },
@@ -144,7 +199,7 @@ async function run(argv) {
 
   await boilerplateUpdatePromise;
 
-  if (argv.endTag === `4.0.1`) {
+  if (endTag === "4.0.1") {
     console.log("fixing npm package...");
     execSync("npm pkg fix");
     console.log("updating lockfile...");
@@ -153,6 +208,14 @@ async function run(argv) {
   }
 }
 
-yargs.command(`$0`, `Update a gulp repository to our template`, opts, run, [
-  guessTags,
-]).argv;
+try {
+  const { values } = parseArgs({ options, strict: true });
+  await run(values);
+} catch (err) {
+  if (err.message) {
+    console.error(err.message);
+  } else {
+    console.error(err);
+  }
+  process.exit(1);
+}