Use native ESM for dev scripts (#12296)

Co-authored-by: Nicolò Ribaudo <nicolo.ribaudo@gmail.com>

scripts/generators/readmes.js

@@ -5,8 +5,11 @@
  * This script write the link to the website in every READMEs.
  */
 
-const { join } = require("path");
-const { readdirSync, writeFileSync } = require("fs");
+import { join } from "path";
+import { readdirSync, writeFileSync } from "fs";
+import { createRequire } from "url";
+
+const require = createRequire(import.meta.url);
 
 const cwd = process.cwd();
 

scripts/generators/tsconfig.js

@@ -1,9 +1,14 @@
-"use strict";
+import path from "path";
+import fs from "fs";
+import { createRequire } from "module";
+import { fileURLToPath } from "url";
 
-const path = require("path");
-const fs = require("fs");
+const require = createRequire(import.meta.url);
 
-const root = path.resolve(__dirname, "../../");
+const root = path.resolve(
+  path.dirname(fileURLToPath(import.meta.url)),
+  "../../"
+);
 
 function getTsPkgs(subRoot) {
   return fs

scripts/integration-tests/utils/bump-babel-dependencies.js

@@ -1,5 +1,6 @@
-const fs = require("fs");
-const path = require("path");
+import fs from "fs";
+import path from "path";
+
 const cwd = process.cwd();
 const packageJSONPath = path.resolve(cwd, "./package.json");
 const content = JSON.parse(fs.readFileSync(packageJSONPath));

scripts/package.json

@@ -0,0 +1 @@
+{ "type": "module" }

scripts/parser-tests/flow/index.js

@@ -1,7 +1,10 @@
-const fs = require("fs").promises;
-const path = require("path");
-const merge = require("mergeiterator");
-const TestRunner = require("../utils/parser-test-runner");
+import fs from "fs/promises";
+import path from "path";
+import { fileURLToPath } from "url";
+import merge from "mergeiterator";
+import TestRunner from "../utils/parser-test-runner.js";
+
+const dirname = path.dirname(fileURLToPath(import.meta.url));
 
 const flowOptionsMapping = {
   esproposal_class_instance_fields: "classProperties",
@@ -88,8 +91,8 @@ async function* loadTests(root) {
 }
 
 const runner = new TestRunner({
-  testDir: path.join(__dirname, "../../../build/flow/src/parser/test/flow"),
-  allowlist: path.join(__dirname, "allowlist.txt"),
+  testDir: path.join(dirname, "../../../build/flow/src/parser/test/flow"),
+  allowlist: path.join(dirname, "allowlist.txt"),
   shouldUpdate: process.argv.includes("--update-allowlist"),
 
   async *getTests() {

scripts/parser-tests/test262/index.js

@@ -1,6 +1,9 @@
-const path = require("path");
-const TestStream = require("test262-stream");
-const TestRunner = require("../utils/parser-test-runner");
+import path from "path";
+import { fileURLToPath } from "url";
+import TestStream from "test262-stream";
+import TestRunner from "../utils/parser-test-runner.js";
+
+const dirname = path.dirname(fileURLToPath(import.meta.url));
 
 const ignoredFeatures = [
   "__getter__",
@@ -163,8 +166,8 @@ function* getPlugins(features) {
 }
 
 const runner = new TestRunner({
-  testDir: path.join(__dirname, "../../../build/test262"),
-  allowlist: path.join(__dirname, "allowlist.txt"),
+  testDir: path.join(dirname, "../../../build/test262"),
+  allowlist: path.join(dirname, "allowlist.txt"),
   logInterval: 500,
   shouldUpdate: process.argv.includes("--update-allowlist"),
 

scripts/parser-tests/typescript/error-codes.js

@@ -8,7 +8,7 @@ Note that babel-parser should not throw for the TypeChecking Diagnostics
 The commented out diagnostic codes will introduce false positive cases that should be addressed in separate PRs.
 */
 
-module.exports = [
+export default [
   // "TS1005", // '{0}' expected.
   "TS1009", // Trailing comma not allowed.
   "TS1014", // A rest parameter must be last in a parameter list.

scripts/parser-tests/typescript/index.js

@@ -1,8 +1,11 @@
-const path = require("path");
-const fs = require("fs").promises;
-const ts = require("../../../build/typescript");
-const TestRunner = require("../utils/parser-test-runner");
-const parsingErrorCodes = require("./error-codes");
+import path from "path";
+import fs from "fs/promises";
+import { fileURLToPath } from "url";
+import ts from "../../../build/typescript/lib/typescript.js";
+import TestRunner from "../utils/parser-test-runner.js";
+import parsingErrorCodes from "./error-codes.js";
+
+const dirname = path.dirname(fileURLToPath(import.meta.url));
 
 async function* loadTests(dir) {
   const names = await fs.readdir(dir);
@@ -21,7 +24,7 @@ const plugins = [
   "dynamicImport",
 ];
 
-const TSTestsPath = path.join(__dirname, "../../../build/typescript/tests");
+const TSTestsPath = path.join(dirname, "../../../build/typescript/tests");
 
 // Check if the baseline errors contain the codes that should also be thrown from babel-parser
 async function baselineContainsParserErrorCodes(testName) {
@@ -45,7 +48,7 @@ async function baselineContainsParserErrorCodes(testName) {
 
 const runner = new TestRunner({
   testDir: path.join(TSTestsPath, "./cases/compiler"),
-  allowlist: path.join(__dirname, "allowlist.txt"),
+  allowlist: path.join(dirname, "allowlist.txt"),
   logInterval: 50,
   shouldUpdate: process.argv.includes("--update-allowlist"),
 

scripts/parser-tests/utils/parser-test-runner.js

@@ -1,8 +1,6 @@
-"use strict";
-
-const fs = require("fs").promises;
-const chalk = require("chalk");
-const { parse: parser } = require("../../../packages/babel-parser");
+import fs from "fs/promises";
+import chalk from "chalk";
+import { parse as parser } from "../../../packages/babel-parser/lib/index.js";
 
 const dot = chalk.gray(".");
 
@@ -234,4 +232,4 @@ class TestRunner {
   }
 }
 
-module.exports = exports = TestRunner;
+export default TestRunner;

scripts/rollup-plugin-babel-source.js

@@ -1,20 +1,27 @@
-const path = require("path");
-const fs = require("fs");
-const dirname = path.join(__dirname, "..");
+import path from "path";
+import fs from "fs";
+import { fileURLToPath } from "url";
+import { createRequire } from "module";
+
+const require = createRequire(import.meta.url);
+const monorepoRoot = path.join(
+  path.dirname(fileURLToPath(import.meta.url)),
+  ".."
+);
 
 const BABEL_SRC_REGEXP =
   path.sep === "/"
     ? /packages\/(babel-[^/]+)\/src\//
     : /packages\\(babel-[^\\]+)\\src\\/;
 
-module.exports = function () {
+export default function () {
   return {
     name: "babel-source",
     load(id) {
       const matches = id.match(BABEL_SRC_REGEXP);
       if (matches) {
         // check if browser field exists for this file and replace
-        const packageFolder = path.join(dirname, "packages", matches[1]);
+        const packageFolder = path.join(monorepoRoot, "packages", matches[1]);
         const packageJson = require(path.join(packageFolder, "package.json"));
 
         if (
@@ -46,7 +53,7 @@ module.exports = function () {
     resolveId(importee) {
       if (importee === "@babel/runtime/regenerator") {
         return path.join(
-          dirname,
+          monorepoRoot,
           "packages",
           "babel-runtime",
           "regenerator",
@@ -61,7 +68,7 @@ module.exports = function () {
       const { pkg, internal } = matches.groups;
 
       // resolve babel package names to their src index file
-      const packageFolder = path.join(dirname, "packages", `babel-${pkg}`);
+      const packageFolder = path.join(monorepoRoot, "packages", `babel-${pkg}`);
 
       let packageJsonSource;
       try {
@@ -98,4 +105,4 @@ module.exports = function () {
       }
     },
   };
-};
+}

scripts/utils/formatCode.js

@@ -1,22 +1,9 @@
-"use strict";
+import prettier from "prettier";
 
-// TODO: Remove this `if` in Babel 8
-// Prettier only supports Node.js 10+, so we can fallback to not formatting
-// o CI on older Node.js versions
+export default function formatCode(code, filename) {
+  const prettierConfig = prettier.resolveConfig.sync(filename);
+  prettierConfig.filepath = filename;
+  prettierConfig.parser = filename.endsWith(".ts") ? "babel-ts" : "babel";
 
-if (process.env.CI && parseInt(process.versions.node, 10) < 10) {
-  module.exports = function formatCode(code) {
-    return code;
-  };
-} else {
-  const prettier = require("prettier");
-
-  module.exports = function formatCode(code, filename) {
-    filename = filename || __filename;
-    const prettierConfig = prettier.resolveConfig.sync(filename);
-    prettierConfig.filepath = filename;
-    prettierConfig.parser = filename.endsWith(".ts") ? "babel-ts" : "babel";
-
-    return prettier.format(code, prettierConfig);
-  };
+  return prettier.format(code, prettierConfig);
 }