feat: add support for modules

This large commit enhances support for JavaScript modules. This adds `lib/index.mjs`, which re-exports `lib/index.js` as a default export and `parse` and `stringify` as named exports. The `module` field in `package.json` now points to this file as the entry point for `import` statements in versions of Node.js that support modules. With this change, `import` statements in Node.js no longer need to use the path `json5/dist/index.mjs`, and should import the module as `json5` instead. `test/index.mjs` ensures that `lib/index.js` and `lib/index.mjs` export the same instance. This follows the guidance in approach json5#1 of [Writing dual packages while avoiding or minimizing hazards][guidance]. `rollup.config.js` now uses `lib/index.mjs` as its entry point for building browser bundles for JavaScript modules environments. It now writes browser bundles to `dist/json5.umd.js` and `dist/json5.esm.js`, as well as minified versions. These are the new canonical paths for browser bundles. The legacy `dist/index.*` paths still exist for backward compatibility, but they will be removed in the next major version. All files in `build` and `lib` now explicitly require `lib/index.js` to ensure that `lib/index.mjs` is not imported. All files in `test` now require the package root to simulate the default behavior of the version of Node.js being tested. [guidance]: https://nodejs.org/dist/latest-v16.x/docs/api/packages.html#writing-dual-packages-while-avoiding-or-minimizing-hazards squash
jordanbtucker · Aug 12, 2022 · ecb408a · ecb408a
1 parent 4798b9d
commit ecb408a
Show file tree

Hide file tree

Showing 14 changed files with 85 additions and 33 deletions.
diff --git a/README.md b/README.md
@@ -92,13 +92,13 @@ import JSON5 from 'json5'
 #### UMD
 ```html
 <!-- This will create a global `JSON5` variable. -->
-<script src="https://unpkg.com/json5@2/dist/index.min.js"></script>
+<script src="https://unpkg.com/json5@2/dist/json5.umd.min.js"></script>
 ```
 
 #### Modules
 ```html
 <script type="module">
-  import JSON5 from 'https://unpkg.com/json5@2/dist/index.min.mjs'
+  import JSON5 from 'https://unpkg.com/json5@2/dist/json5.esm.min.js'
 </script>
 ```
 

diff --git a/build/es5.js b/build/es5.js
@@ -1,6 +1,6 @@
 require('core-js/fn/string/code-point-at')
 require('core-js/fn/string/from-code-point')
 
-const JSON5 = require('../lib')
+const JSON5 = require('../lib/index.js')
 
 module.exports = JSON5
diff --git a/build/package.js b/build/package.js
@@ -1,7 +1,7 @@
 const fs = require('fs')
 const path = require('path')
 
-const JSON5 = require('../lib')
+const JSON5 = require('../lib/index.js')
 
 const pkg = require('../package.json')
 

diff --git a/lib/cli.js b/lib/cli.js
@@ -3,7 +3,7 @@
 const fs = require('fs')
 const path = require('path')
 const pkg = require('../package.json')
-const JSON5 = require('./')
+const JSON5 = require('./index.js')
 
 const argv = parseArgs()
 

diff --git a/lib/index.mjs b/lib/index.mjs
@@ -0,0 +1,7 @@
+/* eslint-disable node/no-unsupported-features/es-syntax */
+
+import JSON5 from './index.js'
+
+export const parse = JSON5.parse
+export const stringify = JSON5.stringify
+export default JSON5
diff --git a/lib/index.mjs.d.ts b/lib/index.mjs.d.ts
@@ -0,0 +1,5 @@
+import parse = require('./parse')
+import stringify = require('./stringify')
+
+export {parse, stringify}
+export default {parse, stringify}
diff --git a/lib/register.js b/lib/register.js
@@ -1,5 +1,5 @@
 const fs = require('fs')
-const JSON5 = require('./')
+const JSON5 = require('./index.js')
 
 // eslint-disable-next-line node/no-deprecated-api
 require.extensions['.json5'] = function (module, filename) {

diff --git a/package.json b/package.json
@@ -3,9 +3,10 @@
   "version": "2.2.1",
   "description": "JSON for Humans",
   "main": "lib/index.js",
-  "module": "dist/index.mjs",
+  "module": "lib/index.mjs",
   "bin": "lib/cli.js",
-  "browser": "dist/index.js",
+  "browser": "dist/json5.umd.js",
+  "unpkg": "dist/json5.umd.js",
   "types": "lib/index.d.ts",
   "files": [
     "lib/",

diff --git a/package.json5 b/package.json5
@@ -4,9 +4,10 @@
   version: '2.2.1',
   description: 'JSON for Humans',
   main: 'lib/index.js',
-  module: 'dist/index.mjs',
+  module: 'lib/index.mjs',
   bin: 'lib/cli.js',
-  browser: 'dist/index.js',
+  browser: 'dist/json5.umd.js',
+  unpkg: 'dist/json5.umd.js',
   types: 'lib/index.d.ts',
   files: [
     'lib/',

diff --git a/rollup.config.js b/rollup.config.js
@@ -8,11 +8,19 @@ module.exports = [
     // ES5 Non-minified
     {
         input: 'build/es5.js',
-        output: {
-            file: pkg.browser,
-            format: 'umd',
-            name: 'JSON5',
-        },
+        output: [
+            {
+                file: pkg.browser,
+                format: 'umd',
+                name: 'JSON5',
+            },
+            {
+                // Legacy path
+                file: 'dist/index.js',
+                format: 'umd',
+                name: 'JSON5',
+            },
+        ],
         plugins: [
             resolve(),
             commonjs(),
@@ -22,11 +30,19 @@ module.exports = [
     // ES5 Minified
     {
         input: 'build/es5.js',
-        output: {
-            file: pkg.browser.replace(/\.js$/, '.min.js'),
-            format: 'umd',
-            name: 'JSON5',
-        },
+        output: [
+            {
+                file: pkg.browser.replace(/\.js$/, '.min.js'),
+                format: 'umd',
+                name: 'JSON5',
+            },
+            {
+                // Legacy path
+                file: 'dist/index.min.js',
+                format: 'umd',
+                name: 'JSON5',
+            },
+        ],
         plugins: [
             resolve(),
             commonjs(),
@@ -36,23 +52,37 @@ module.exports = [
     },
     // ES6 Modules Non-minified
     {
-        input: 'lib/index.js',
-        output: {
-            file: pkg.browser.replace(/\.js$/, '.mjs'),
-            format: 'esm',
-        },
+        input: 'lib/index.mjs',
+        output: [
+            {
+                file: pkg.browser.replace(/\.umd\.js$/, '.esm.js'),
+                format: 'esm',
+            },
+            {
+                // Legacy path
+                file: 'dist/index.mjs',
+                format: 'esm',
+            },
+        ],
         plugins: [
             resolve(),
             commonjs(),
         ],
     },
     // ES6 Modules Minified
     {
-        input: 'lib/index.js',
-        output: {
-            file: pkg.browser.replace(/\.js$/, '.min.mjs'),
-            format: 'esm',
-        },
+        input: 'lib/index.mjs',
+        output: [
+            {
+                file: pkg.browser.replace(/\.umd\.js$/, '.esm.min.mjs'),
+                format: 'esm',
+            },
+            {
+                // Legacy path
+                file: 'dist/index.min.mjs',
+                format: 'esm',
+            },
+        ],
         plugins: [
             resolve(),
             commonjs(),

diff --git a/test/errors.js b/test/errors.js
@@ -1,5 +1,5 @@
 const assert = require('assert')
-const JSON5 = require('../lib')
+const JSON5 = require('..')
 
 require('tap').mochaGlobals()
 

diff --git a/test/index.mjs b/test/index.mjs
@@ -0,0 +1,8 @@
+/* eslint-disable import/no-duplicates, node/no-unsupported-features/es-syntax */
+
+import JSON5Modules from '..'
+import JSON5CommonJS from '../lib/index.js'
+
+import t from 'tap'
+
+t.strictSame(JSON5Modules, JSON5CommonJS, 'Modules export and CommonJS export are the same')
diff --git a/test/parse.js b/test/parse.js
@@ -1,6 +1,6 @@
 const assert = require('assert')
 const sinon = require('sinon')
-const JSON5 = require('../lib')
+const JSON5 = require('..')
 
 require('tap').mochaGlobals()
 

diff --git a/test/stringify.js b/test/stringify.js
@@ -1,5 +1,5 @@
 const assert = require('assert')
-const JSON5 = require('../lib')
+const JSON5 = require('..')
 
 require('tap').mochaGlobals()