Dual packaging, without breaking existing consumers (#628)

Co-authored-by: Yasumasa Ashida <ys.ashida@gmail.com>

test/package/assertions.cjs

@@ -0,0 +1,192 @@
+/* eslint-disable */
+/**
+ * Runs *inside* a throwaway directory that has the packed bowser tarball
+ * extracted into ./node_modules/bowser, so that bare specifiers resolve the way
+ * they would for a real consumer.
+ *
+ * Deliberately written as ES5-compatible CommonJS: this file has to run on
+ * every Node version bowser claims to support, down to 12.16.3. No optional
+ * chaining, no nullish coalescing, no top-level await.
+ */
+var assert = require('assert');
+var fs = require('fs');
+var path = require('path');
+var vm = require('vm');
+
+var UA = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 '
+  + '(KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36';
+
+var passed = 0;
+function check(name, fn) {
+  fn();
+  passed += 1;
+  console.log('  ok  ' + name);
+}
+
+/** Node version gate — ESM was unflagged in 12.17.0. */
+function nodeAtLeast(major, minor) {
+  var parts = process.versions.node.split('.');
+  var m = Number(parts[0]);
+  var n = Number(parts[1]);
+  return m > major || (m === major && n >= minor);
+}
+
+console.log('bowser package smoke test on Node ' + process.versions.node);
+
+// --- The CommonJS contract -------------------------------------------------
+// `require('bowser')` must be the Bowser class itself. If it ever becomes
+// `{ default, parse, getParser }`, every existing consumer breaks.
+
+check('require("bowser") is the class, not a module namespace', function () {
+  var Bowser = require('bowser');
+  assert.strictEqual(typeof Bowser, 'function');
+  assert.strictEqual(typeof Bowser.getParser, 'function');
+  assert.strictEqual(typeof Bowser.parse, 'function');
+  assert.strictEqual(
+    Bowser.default,
+    undefined,
+    'require("bowser").default is set — the CJS interop unwrap was lost',
+  );
+});
+
+check('require("bowser") parses a user agent', function () {
+  var Bowser = require('bowser');
+  assert.strictEqual(Bowser.parse(UA).browser.name, 'Chrome');
+  assert.strictEqual(Bowser.getParser(UA).getBrowserName(), 'Chrome');
+});
+
+check('constant maps are exposed', function () {
+  var Bowser = require('bowser');
+  assert.strictEqual(typeof Bowser.BROWSER_MAP, 'object');
+  assert.strictEqual(typeof Bowser.ENGINE_MAP, 'object');
+  assert.strictEqual(typeof Bowser.OS_MAP, 'object');
+  assert.strictEqual(typeof Bowser.PLATFORMS_MAP, 'object');
+});
+
+// --- Legacy deep paths -----------------------------------------------------
+// These resolved before the exports map existed. Adding an exports map without
+// listing them turns them into ERR_PACKAGE_PATH_NOT_EXPORTED.
+
+['bowser/es5.js', 'bowser/es5', 'bowser/bundled.js', 'bowser/bundled'].forEach(function (id) {
+  check('require("' + id + '") works', function () {
+    var B = require(id);
+    assert.strictEqual(typeof B, 'function');
+    assert.strictEqual(B.parse(UA).browser.name, 'Chrome');
+  });
+});
+
+// The src/*.js files are ES module sources, so they resolve but do not execute
+// under require(). Bundlers are the real consumer here. Assert resolution only.
+[
+  'bowser.js', 'constants.js', 'parser.js', 'parser-browsers.js',
+  'parser-engines.js', 'parser-os.js', 'parser-platforms.js', 'utils.js',
+].forEach(function (file) {
+  var withExt = 'bowser/src/' + file;
+  var withoutExt = withExt.replace(/\.js$/, '');
+  check('resolves "' + withExt + '" and "' + withoutExt + '"', function () {
+    assert.ok(fs.existsSync(require.resolve(withExt)));
+    assert.ok(fs.existsSync(require.resolve(withoutExt)));
+  });
+});
+
+check('require.resolve("bowser/package.json") works', function () {
+  assert.ok(fs.existsSync(require.resolve('bowser/package.json')));
+});
+
+// --- The published manifest ------------------------------------------------
+
+check('main/browser/module/types fields are unchanged', function () {
+  var pkg = require('bowser/package.json');
+  assert.strictEqual(pkg.main, 'es5.js');
+  assert.strictEqual(pkg.browser, 'es5.js');
+  assert.strictEqual(pkg.module, 'src/bowser.js');
+  assert.strictEqual(pkg.types, 'index.d.ts');
+});
+
+check('no "engines" field (would warn/fail installs on old Node)', function () {
+  var pkg = require('bowser/package.json');
+  assert.strictEqual(pkg.engines, undefined);
+});
+
+check('no "type" field (would reclassify es5.js as ESM)', function () {
+  var pkg = require('bowser/package.json');
+  assert.strictEqual(pkg.type, undefined);
+});
+
+check('published file list is exactly what we expect', function () {
+  var root = path.dirname(require.resolve('bowser/package.json'));
+  var actual = [];
+  (function walk(dir, prefix) {
+    fs.readdirSync(dir).forEach(function (name) {
+      var full = path.join(dir, name);
+      if (fs.statSync(full).isDirectory()) walk(full, prefix + name + '/');
+      else actual.push(prefix + name);
+    });
+  }(root, ''));
+
+  var expected = [
+    'LICENSE', 'README.md', 'bowser.mjs', 'bundled.js', 'es5.js',
+    'index.d.mts', 'index.d.ts', 'package.json',
+    'src/bowser.js', 'src/constants.js', 'src/parser-browsers.js',
+    'src/parser-engines.js', 'src/parser-os.js', 'src/parser-platforms.js',
+    'src/parser.js', 'src/utils.js',
+  ];
+  assert.deepStrictEqual(actual.sort(), expected.sort());
+});
+
+// --- The UMD / CDN contract ------------------------------------------------
+// Script-tag consumers get `window.bowser` (lowercase). Nothing else covers
+// this path, and a renamed global fails silently at runtime.
+
+check('es5.js sets a lowercase `bowser` global when loaded as a script', function () {
+  var file = require.resolve('bowser/es5.js');
+  var sandbox = {};
+  sandbox.self = sandbox;
+  vm.runInNewContext(fs.readFileSync(file, 'utf8'), sandbox);
+  assert.strictEqual(typeof sandbox.bowser, 'function', 'global `bowser` not set');
+  assert.strictEqual(sandbox.bowser.parse(UA).browser.name, 'Chrome');
+  assert.strictEqual(sandbox.Bowser, undefined, 'unexpected capitalised global');
+});
+
+check('es5.js contains no ES6 template literals', function () {
+  // rolldown's built-in (oxc) minifier rewrites every string literal as a
+  // template literal, which is a syntax error in the old browsers this bundle
+  // targets. Guards against the terser step being dropped from the build.
+  var code = fs.readFileSync(require.resolve('bowser/es5.js'), 'utf8');
+  assert.strictEqual(code.indexOf('`'), -1, 'es5.js contains a backtick');
+});
+
+check('es5.js keeps the copyright banner', function () {
+  var code = fs.readFileSync(require.resolve('bowser/es5.js'), 'utf8');
+  assert.ok(code.indexOf('Bowser - a browser detector') !== -1);
+});
+
+// --- The ESM contract ------------------------------------------------------
+
+if (!nodeAtLeast(12, 17)) {
+  console.log('  --  skipping ESM checks (Node ' + process.versions.node + ' < 12.17)');
+  console.log('\n' + passed + ' checks passed');
+} else {
+  // eslint-disable-next-line no-eval
+  eval('import("bowser")')
+    .then(function (mod) {
+      check('import("bowser") has a working default export', function () {
+        assert.strictEqual(typeof mod.default, 'function');
+        assert.strictEqual(mod.default.parse(UA).browser.name, 'Chrome');
+      });
+      // This is issue #511: named imports must work, and must work unbound.
+      check('import("bowser") has working named exports', function () {
+        assert.strictEqual(typeof mod.parse, 'function');
+        assert.strictEqual(typeof mod.getParser, 'function');
+        var parse = mod.parse;
+        var getParser = mod.getParser;
+        assert.strictEqual(parse(UA).browser.name, 'Chrome');
+        assert.strictEqual(getParser(UA).getBrowserName(), 'Chrome');
+      });
+      console.log('\n' + passed + ' checks passed');
+    })
+    .catch(function (err) {
+      console.error('\nESM check failed: ' + err.stack);
+      process.exit(1);
+    });
+}