fix: expose the constant maps on the ESM namespace (#642)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -39,8 +39,9 @@ import * as Bowser from "bowser"; // TypeScript
 import Bowser from "bowser"; // ES6 (and TypeScript with --esModuleInterop enabled)
 ```
 
-The ES module build also exposes `parse` and `getParser` as named exports, so
-you can import just the part you use and let your bundler drop the rest:
+The ES module build also exposes `parse`, `getParser`, `BROWSER_MAP`,
+`ENGINE_MAP`, `OS_MAP` and `PLATFORMS_MAP` as named exports, so you can import
+just the part you use and let your bundler drop the rest:
 
 ```javascript
 import { getParser, parse } from "bowser";

index.d.mts

@@ -5,8 +5,9 @@
 // condition and stays the source of truth for the type declarations.
 //
 // This file describes `bowser.mjs`, which is a real ES module: it has a default
-// export *and* the `parse` / `getParser` named exports. It is reached via the
-// `import` condition. Declaring it separately is what keeps the types honest
+// export *and* every member of the CommonJS namespace as a named export, so
+// `import * as Bowser from 'bowser'` sees what `require('bowser')` does. It is
+// reached via the `import` condition. Declaring it separately is what keeps the types honest
 // for `moduleResolution: node16`/`bundler` consumers — reusing `index.d.ts` for
 // both conditions would describe an ES module with CommonJS types.
 
@@ -16,14 +17,25 @@ export default Bowser;
 
 export declare const parse: typeof Bowser.parse;
 export declare const getParser: typeof Bowser.getParser;
-
-// BROWSER_MAP / ENGINE_MAP / OS_MAP / PLATFORMS_MAP are *not* named exports of
-// bowser.mjs — they exist only as static getters on the class. Declaring them
-// here would let TypeScript accept `import { BROWSER_MAP } from 'bowser'`,
-// which throws at runtime. Reach them via the default export instead.
+export declare const BROWSER_MAP: typeof Bowser.BROWSER_MAP;
+export declare const ENGINE_MAP: typeof Bowser.ENGINE_MAP;
+export declare const OS_MAP: typeof Bowser.OS_MAP;
+export declare const PLATFORMS_MAP: typeof Bowser.PLATFORMS_MAP;
 
 export type ClientHints = Bowser.ClientHints;
+// `Parser` is both the parser type and, as in `index.d.ts`, a namespace of the
+// result types, so `Bowser.Parser.ParsedResult` works on a namespace import.
 export type Parser = Bowser.Parser.Parser;
+export declare namespace Parser {
+  type Parser = Bowser.Parser.Parser;
+  type ParsedResult = Bowser.Parser.ParsedResult;
+  type Details = Bowser.Parser.Details;
+  type BrowserDetails = Bowser.Parser.BrowserDetails;
+  type EngineDetails = Bowser.Parser.EngineDetails;
+  type OSDetails = Bowser.Parser.OSDetails;
+  type PlatformDetails = Bowser.Parser.PlatformDetails;
+  type checkTree = Bowser.Parser.checkTree;
+}
 export type ParsedResult = Bowser.Parser.ParsedResult;
 export type Details = Bowser.Parser.Details;
 export type BrowserDetails = Bowser.Parser.BrowserDetails;

src/bowser.js

@@ -92,3 +92,10 @@ class Bowser {
 
 export default Bowser;
 export const { parse, getParser } = Bowser;
+// Named too, so `import * as Bowser` has every member the UMD build has.
+export {
+  BROWSER_MAP,
+  ENGINE_MAP,
+  OS_MAP,
+  PLATFORMS_MAP,
+};

test/package/assertions.cjs

@@ -218,6 +218,13 @@ if (!nodeAtLeast(12, 17)) {
         assert.strictEqual(parse(UA).browser.name, 'Chrome');
         assert.strictEqual(getParser(UA).getBrowserName(), 'Chrome');
       });
+      // `import * as Bowser` must see every member `require('bowser')` has.
+      check('import("bowser") has the constant maps as named exports', function () {
+        ['BROWSER_MAP', 'ENGINE_MAP', 'OS_MAP', 'PLATFORMS_MAP'].forEach(function (key) {
+          assert.strictEqual(typeof mod[key], 'object', key);
+          assert.strictEqual(mod[key], mod.default[key], key);
+        });
+      });
       console.log('\n' + passed + ' checks passed');
     })
     .catch(function (err) {

test/types/check.mjs

@@ -16,9 +16,9 @@
  * export declared in `index.d.mts` that `bowser.mjs` does not actually have.
  *
  * Both directions are asserted. The negative cases matter as much as the
- * positive ones: `index.d.mts` deliberately omits `BROWSER_MAP` and friends as
- * named exports because importing them that way throws at runtime, and only a
- * compile that is expected to *fail* can hold that line.
+ * positive ones: `Parser` is only a type, and constructing it from an import
+ * would throw at runtime. Only a compile that is expected to *fail* can hold
+ * that line.
  *
  * Either way the package is installed into a real `node_modules` and resolved
  * by the normal upward walk, so the exports map, the `types` field and the
@@ -57,11 +57,8 @@ const MODES = [
  * promising something `bowser.mjs` will not deliver.
  */
 const MUST_NOT_COMPILE = [
-  ['BROWSER_MAP is not a named export', 'import { BROWSER_MAP } from "bowser"; export default BROWSER_MAP;'],
-  ['OS_MAP is not a named export', 'import { OS_MAP } from "bowser"; export default OS_MAP;'],
-  ['ENGINE_MAP is not a named export', 'import { ENGINE_MAP } from "bowser"; export default ENGINE_MAP;'],
-  ['PLATFORMS_MAP is not a named export', 'import { PLATFORMS_MAP } from "bowser"; export default PLATFORMS_MAP;'],
   ['Parser is a type, not a value', 'import { Parser } from "bowser"; export default new Parser("x");'],
+  ['Parser is a type, not a value, on the namespace', 'import * as B from "bowser"; export default new B.Parser("x");'],
 ];
 
 const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'bowser-types-'));

test/types/fixtures/consumer-esm.ts

@@ -1,7 +1,10 @@
 // An ES module consumer: default plus named imports, types imported as types.
 // This is `moduleResolution: node16` (from ESM), `nodenext` and `bundler`.
-import Bowser, { parse, getParser } from 'bowser';
+import Bowser, { parse, getParser, BROWSER_MAP, ENGINE_MAP, OS_MAP, PLATFORMS_MAP } from 'bowser';
 import type { ParsedResult, Parser, ClientHints, checkTree } from 'bowser';
+// The namespace import the README documents for TypeScript: it must offer
+// everything the CommonJS `export =` namespace does.
+import * as BowserNS from 'bowser';
 
 const UA = 'Mozilla/5.0 (Macintosh) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36';
 
@@ -10,8 +13,15 @@ const parser: Parser = getParser(UA);
 const tree: checkTree = { chrome: '>100' };
 const satisfies: boolean | undefined = parser.satisfies(tree);
 const hints: ClientHints = { mobile: false };
-// BROWSER_MAP is deliberately not a named export of bowser.mjs — it only
-// exists as a static on the class. Reaching it any other way must not compile.
-const maps: Record<string, string> = Bowser.BROWSER_MAP;
+const maps: Array<Record<string, string>> = [
+  Bowser.BROWSER_MAP, BROWSER_MAP, ENGINE_MAP, OS_MAP, PLATFORMS_MAP,
+];
 
-export { result, satisfies, hints, maps };
+const nsResult: BowserNS.Parser.ParsedResult = BowserNS.parse(UA);
+const nsParser: BowserNS.Parser.Parser = BowserNS.getParser(UA);
+const nsHints: BowserNS.ClientHints = { mobile: false };
+const nsMaps: Array<Record<string, string>> = [
+  BowserNS.BROWSER_MAP, BowserNS.ENGINE_MAP, BowserNS.OS_MAP, BowserNS.PLATFORMS_MAP,
+];
+
+export { result, satisfies, hints, maps, nsResult, nsParser, nsHints, nsMaps };

test/unit/bowser.js

@@ -1,5 +1,6 @@
 import test from 'ava';
 import Bowser from '../../src/bowser';
+import * as BowserNS from '../../src/bowser';
 import Parser from '../../src/parser';
 
 const UA = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36 OPR/43.0.2442.1165';
@@ -16,3 +17,14 @@ test('Bowser`s constructor fails if UA is empty', (t) => {
 test('Bowser.parse parses UA and returns result', (t) => {
   t.deepEqual(Bowser.parse(UA), browser.getResult());
 });
+
+test('every static member of Bowser is also a named export', (t) => {
+  // `require('bowser')` is the class itself, so `import * as Bowser` has to
+  // expose the same members for code moving between the two to keep working.
+  const statics = Object.getOwnPropertyNames(Bowser)
+    .filter(key => ['length', 'name', 'prototype'].indexOf(key) === -1);
+  t.true(statics.length > 0);
+  statics.forEach((key) => {
+    t.is(BowserNS[key], Bowser[key], key);
+  });
+});