Bundle CLI as ES Module (#13091)

bin/prettier.cjs

@@ -11,14 +11,6 @@ function runCli(cli) {
   return cli.run(process.argv.slice(2));
 }
 
-module.exports.promise = (function () {
-  if (process.env.NODE_ENV !== "production") {
-    var dynamicImport = new Function("module", "return import(module)");
+var dynamicImport = new Function("module", "return import(module)");
 
-    return dynamicImport("../src/cli/index.js").then(runCli);
-  }
-
-  var cli = require("../src/cli/index.js");
-
-  return runCli(cli);
-})();
+module.exports.promise = dynamicImport("../src/cli/index.js").then(runCli);

scripts/build/build.mjs

@@ -145,7 +145,7 @@ async function preparePackage() {
     prepublishOnly:
       "node -e \"assert.equal(require('.').version, require('..').version)\"",
   };
-  packageJson.files = ["*.js", "esm/*.mjs"];
+  packageJson.files = ["*.js", "*.mjs", "esm/*.mjs"];
   await writeJson(path.join(DIST_DIR, "package.json"), packageJson);
 
   for (const file of ["README.md", "LICENSE"]) {

scripts/build/bundler.mjs

@@ -12,6 +12,7 @@ import esbuildPluginInteropDefault from "./esbuild-plugins/interop-default.mjs";
 import esbuildPluginVisualizer from "./esbuild-plugins/visualizer.mjs";
 import esbuildPluginStripNodeProtocol from "./esbuild-plugins/strip-node-protocol.mjs";
 import esbuildPluginThrowWarnings from "./esbuild-plugins/throw-warnings.mjs";
+import esbuildPluginShimCommonjsObjects from "./esbuild-plugins/shim-commonjs-objects.mjs";
 import bundles from "./config.mjs";
 
 const { dirname, readJsonSync, require } = createEsmUtils(import.meta);
@@ -89,8 +90,12 @@ function* getEsbuildOptions(bundle, buildOptions) {
 
   // Replace other bundled files
   if (bundle.target === "node") {
-    // Replace bundled files and `package.json` with dynamic `require()`
+    // Replace other bundled files and `package.json` with dynamic `require()`
     for (const { input, output } of bundledFiles) {
+      if (input === path.join(PROJECT_ROOT, bundle.input)) {
+        continue;
+      }
+
       replaceModule.push({ module: input, external: output });
     }
 
@@ -241,10 +246,15 @@ function* getEsbuildOptions(bundle, buildOptions) {
       esbuildOptions.plugins.push(esbuildPluginInteropDefault());
     }
 
+    // https://github.com/evanw/esbuild/issues/1921
+    if (bundle.format === "esm") {
+      esbuildOptions.plugins.push(esbuildPluginShimCommonjsObjects());
+    }
+
     yield {
       ...esbuildOptions,
       outfile: bundle.output,
-      format: "cjs",
+      format: bundle.format ?? "cjs",
     };
   }
 }

scripts/build/config.mjs

@@ -1,6 +1,7 @@
 import path from "node:path";
 import { createRequire } from "node:module";
 import createEsmUtils from "esm-utils";
+import { PROJECT_ROOT } from "../utils/index.mjs";
 
 const { require, dirname } = createEsmUtils(import.meta);
 
@@ -340,10 +341,17 @@ const coreBundles = [
     input: "bin/prettier.cjs",
     output: "bin-prettier.js",
     esbuildTarget: ["node0.10"],
+    replaceModule: [
+      {
+        module: path.join(PROJECT_ROOT, "bin/prettier.cjs"),
+        process: (text) => text.replace('"../src/cli/index.js"', '"./cli.mjs"'),
+      },
+    ],
   },
   {
     input: "src/cli/index.js",
-    output: "cli.js",
+    output: "cli.mjs",
+    format: "esm",
     external: ["benchmark"],
     interopDefault: false,
     replaceModule: [replaceDiffPackageEntry("lib/patch/create.js")],

scripts/build/esbuild-plugins/shim-commonjs-objects.mjs

@@ -0,0 +1,36 @@
+import fs from "node:fs";
+import { outdent } from "outdent";
+
+export default function esbuildPluginShimCommonjsObjects() {
+  return {
+    name: "shim-commonjs-objects",
+    setup(build) {
+      const { onEnd, initialOptions: esbuildOptions } = build;
+
+      onEnd(() => {
+        const file = esbuildOptions.outfile;
+
+        if (!fs.existsSync(file)) {
+          throw new Error(`${file} not exists`);
+        }
+
+        const text = fs.readFileSync(file, "utf8");
+
+        // Use `__prettier` prefix to avoid possible conflicts
+        fs.writeFileSync(
+          file,
+          outdent`
+            import { createRequire as __prettierCreateRequire } from "module";
+            import { fileURLToPath as __prettierFileUrlToPath } from "url";
+            import { dirname as __prettierDirname } from "path";
+            const require = __prettierCreateRequire(import.meta.url);
+            const __filename = __prettierFileUrlToPath(import.meta.url);
+            const __dirname = __prettierDirname(__filename);
+
+            ${text}
+          `
+        );
+      });
+    },
+  };
+}