Add CJS build fallback

package.json

@@ -11,12 +11,12 @@
   ],
   "repository": "markdown-it/markdown-it",
   "license": "MIT",
-  "main": "dist/markdown-it.js",
+  "main": "dist/markdown-it.cjs.js",
   "module": "index.mjs",
   "exports": {
     ".": {
       "import": "./index.mjs",
-      "require": "./dist/markdown-it.js"
+      "require": "./dist/markdown-it.cjs.js"
     },
     "./*": {
       "require": "./*",
@@ -28,16 +28,16 @@
   },
   "scripts": {
     "lint": "eslint --ext js --ext mjs .",
-    "test": "npm run lint && c8 -r text -r html -r lcov mocha && node support/specsplit.mjs",
+    "test": "npm run lint && CJS_ONLY=1 npm run build && c8 --exclude dist --exclude test -r text -r html -r lcov mocha && node support/specsplit.mjs",
     "doc": "node support/build_doc.mjs",
     "gh-doc": "npm run doc && gh-pages -d apidoc -f",
     "demo": "npm run lint && node support/build_demo.mjs",
     "gh-demo": "npm run demo && gh-pages -d demo -f -b master -r git@github.com:markdown-it/markdown-it.github.io.git",
-    "build": "npm run lint && rollup -c support/rollup.config.mjs",
+    "build": "rollup -c support/rollup.config.mjs",
     "benchmark-deps": "npm install --prefix benchmark/extra/ -g marked@0.3.6 commonmark@0.26.0 markdown-it/markdown-it.git#2.2.1",
     "specsplit": "support/specsplit.mjs good -o test/fixtures/commonmark/good.txt && support/specsplit.mjs bad -o test/fixtures/commonmark/bad.txt && support/specsplit.mjs",
     "todo": "grep 'TODO' -n -r ./lib 2>/dev/null",
-    "prepublishOnly": "npm run build && npm run gh-demo && npm run gh-doc"
+    "prepublishOnly": "npm test && npm run build && npm run gh-demo && npm run gh-doc"
   },
   "files": [
     "index.mjs",

support/rollup.config.mjs

@@ -1,12 +1,11 @@
-import nodeResolve from '@rollup/plugin-node-resolve'
-import commonjs from '@rollup/plugin-commonjs'
+import resolve from '@rollup/plugin-node-resolve'
 import terser from '@rollup/plugin-terser'
 import { babel } from '@rollup/plugin-babel'
 import { readFileSync } from 'fs'
 
 const pkg = JSON.parse(readFileSync(new URL('../package.json', import.meta.url)))
 
-export default {
+const config_umd_full = {
   input: 'index.mjs',
   output: [
     {
@@ -18,12 +17,7 @@ export default {
         terser({
           mangle: false,
           compress: false,
-          format: {
-            comments: 'all',
-            beautify: true,
-            ascii_only: true,
-            indent_level: 2
-          }
+          format: { comments: 'all', beautify: true, ascii_only: true, indent_level: 2 }
         })
       ]
     },
@@ -33,16 +27,13 @@ export default {
       name: 'markdownit',
       plugins: [
         terser({
-          format: {
-            ascii_only: true
-          }
+          format: { ascii_only: true }
         })
       ]
     }
   ],
   plugins: [
-    nodeResolve({ preferBuiltins: true }),
-    commonjs(),
+    resolve(),
     babel({ babelHelpers: 'bundled' }),
     {
       banner () {
@@ -51,3 +42,25 @@ export default {
     }
   ]
 }
+
+const config_cjs_no_deps = {
+  input: 'index.mjs',
+  output: {
+    file: 'dist/markdown-it.cjs.js',
+    format: 'cjs'
+  },
+  external: Object.keys(pkg.dependencies),
+  plugins: [
+    resolve(),
+    babel({ babelHelpers: 'bundled' })
+  ]
+}
+
+let config = [
+  config_umd_full,
+  config_cjs_no_deps
+]
+
+if (process.env.CJS_ONLY) config = [config_cjs_no_deps]
+
+export default config

test/cjs.js

@@ -0,0 +1,10 @@
+'use strict'
+
+const assert = require('assert')
+const md = require('../')()
+
+describe('CJS', () => {
+  it('require', () => {
+    assert.strictEqual(md.render('abc'), '<p>abc</p>\n')
+  })
+})