feat: build cjs modules

package.json

@@ -14,7 +14,12 @@
   "repository": "https://github.com/nlibjs/typing",
   "type": "module",
   "main": "./esm/index.mjs",
+  "exports": {
+    "import": "./esm/index.mjs",
+    "require": "./cjs/index.cjs"
+  },
   "files": [
+    "cjs",
     "esm",
     "!**/*.test.*"
   ],
@@ -26,6 +31,9 @@
     "build": "run-s build:*",
     "build:index": "npx @nlib/indexen --output src/index.mts \"./**/*.mts\"",
     "build:esm": "tsc",
+    "build:cjs": "run-s build:cjs:*",
+    "build:cjs:tsc": "tsc --project tsconfig.cjs.json",
+    "build:cjs:rename": "node rename-cjs.mjs",
     "version": "npx @nlib/changelog --output CHANGELOG.md && git add CHANGELOG.md"
   },
   "devDependencies": {

rename-cjs.mjs

@@ -0,0 +1,42 @@
+/* eslint-env es6 */
+//@ts-check
+import * as fs from 'node:fs/promises';
+import { URL } from 'node:url';
+import * as console from 'node:console';
+
+/**
+ * @param {URL} file
+ * @returns {AsyncGenerator<URL>}
+ */
+export const listFiles = async function* (file) {
+  const stats = await fs.stat(file);
+  if (stats.isFile()) {
+    yield file;
+    return;
+  }
+  if (stats.isDirectory()) {
+    file.pathname = file.pathname.replace(/\/*$/, '/');
+    for (const name of await fs.readdir(file)) {
+      yield* listFiles(new URL(name, file));
+    }
+  }
+};
+
+/** @type {Array<[URL, URL]>} */
+const renames = [];
+const cjsDir = new URL('cjs/', import.meta.url);
+for await (const file of listFiles(cjsDir)) {
+  if (/\.m[jt]s$/.test(file.pathname)) {
+    const renamed = new URL(file.href);
+    renamed.pathname = renamed.pathname.replace(/\.m([jt])s$/, '.c$1s');
+    renames.push([file, renamed]);
+  }
+}
+await Promise.all(
+  renames.map(async ([from, to]) => {
+    let code = await fs.readFile(from, 'utf8');
+    code = code.replace(/\.m([jt])s(['"])/g, '.c$1s$2');
+    await fs.writeFile(to, code);
+    console.info('renamed', to.pathname.slice(cjsDir.pathname.length));
+  }),
+);

tsconfig.cjs.json

@@ -0,0 +1,9 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "target": "ESNext",
+    "module": "CommonJS",
+    "moduleResolution": "Node",
+    "outDir": "cjs"
+  }
+}