Rework variants to reduce bundle size

.github/workflows/publish.yml

@@ -17,14 +17,14 @@ jobs:
         # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           ref: ${{ github.event.release.target_commitish }}
       - name: Validate and extract release information
         id: release
         uses: manovotny/github-releases-for-automated-package-publishing-action@v2.0.1
       - name: Use Node.js ${{ matrix.node-version }}
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
           registry-url: 'https://registry.npmjs.org'

.github/workflows/pull-request.yml

@@ -15,12 +15,12 @@ jobs:
       )
     steps:
       - name: Check out merge commit of pull request
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           ref: ${{ github.event.pull_request.merge_commit_sha }}
           submodules: true
       - name: Use Node.js 20
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: 20
           cache: npm
@@ -30,3 +30,4 @@ jobs:
       - run: npm run test:types
       - run: npm run test:unit
       - run: npm run test:wpt:node
+      - run: npm run test:bundlers

.github/workflows/push.yml

@@ -12,11 +12,11 @@ jobs:
       !contains(github.event.head_commit.message, '[skip ci]')
     steps:
       - name: Check out commit
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: true
       - name: Use Node.js ${{ matrix.node-version }}
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
           cache: npm
@@ -26,12 +26,13 @@ jobs:
       - run: npm run test:types
       - run: npm run test:unit
       - run: npm run test:wpt:node
+      - run: npm run test:bundlers
 
   test-browser:
     name: ${{ matrix.browser }}
     runs-on: ubuntu-latest
     container:
-      image: mcr.microsoft.com/playwright:v1.40.0-jammy
+      image: mcr.microsoft.com/playwright:v1.42.0-jammy
     strategy:
       fail-fast: false
       matrix:
@@ -40,11 +41,11 @@ jobs:
       !contains(github.event.head_commit.message, '[skip ci]')
     steps:
       - name: Check out commit
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: true
       - name: Use Node.js 20
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: 20
           cache: npm

.gitignore

@@ -137,6 +137,7 @@ typings/
 
 ### Project
 /dist/
-!/dist/types/ts3.6/polyfill.d.ts
 /lib/
 /temp/
+/types/ponyfill.d.ts
+/types/tsdoc-metadata.json

CHANGELOG.md

@@ -10,6 +10,28 @@
 > - 🏠 Internal
 > - 💅 Polish
 
+## Unreleased
+
+* 💥 Rework the list of variants to have more modern defaults.
+  The table below shows how to upgrade your v3 import to their equivalent v4 import.
+  See the [migration guide](/~https://github.com/MattiasBuelens/web-streams-polyfill/blob/v4/MIGRATING.md) for more information.
+  ([#82](/~https://github.com/MattiasBuelens/web-streams-polyfill/issues/82), [#139](/~https://github.com/MattiasBuelens/web-streams-polyfill/pull/139))
+* 💥 Remove the ES2018 variant, in favor of the ES2015 variant.
+* 💥 Switch to [subpath exports](https://nodejs.org/api/packages.html#subpath-exports) for variants.
+  * Node 12 or higher is required to `import` or `require()` a variant.
+  * When using TypeScript, version 4.7 or higher is now required. Additionally, [`moduleResolution`](https://www.typescriptlang.org/tsconfig#moduleResolution) must be set to `"node16"`, `"nodenext"` or `"bundler"`.
+* 🚀 Support [importing as ESM in Node](https://nodejs.org/api/esm.html).
+* 💅 Minify all code in the published package, to reduce the download size.
+
+| v3 import | v4 import | description |
+| --- | --- | --- |
+| `web-streams-polyfill` | `web-streams-polyfill/polyfill/es5` | ES5+ polyfill |
+| `web-streams-polyfill/es6` | `web-streams-polyfill/polyfill` | ES2015+ polyfill |
+| `web-streams-polyfill/es2018` | `web-streams-polyfill/polyfill` | ES2015+ polyfill |
+| `web-streams-polyfill/ponyfill` | `web-streams-polyfill/es5` | ES5+ ponyfill |
+| `web-streams-polyfill/ponyfill/es6` | `web-streams-polyfill` | ES2015+ ponyfill |
+| `web-streams-polyfill/ponyfill/es2018` | `web-streams-polyfill` | ES2015+ ponyfill |
+
 ## 3.3.3 (2024-02-16)
 
 * 🐛 Fix `ReadableStream` to match TypeScript's `AsyncIterable<R>` type. ([#141](/~https://github.com/MattiasBuelens/web-streams-polyfill/issues/141), [#142](/~https://github.com/MattiasBuelens/web-streams-polyfill/pull/142))

CONTRIBUTING.md

@@ -12,6 +12,7 @@
   - `npm run test:wpt` runs the [Web Platform Tests for Streams][wpt-streams] against the generated JavaScript bundle, to verify that the polyfill's run-time behavior matches the specification.
   - `npm run test:types` runs the TypeScript compiler against some reference code that uses the generated type definitions, to verify that the code successfully passes the type check.
   - `npm run test:unit` runs a few unit tests in a Node environment, to verify that the polyfill also works without a browser environment.
+  - `npm run test:bundlers` runs integration tests with popular bundlers, to verify that they can correctly resolve and bundle the polyfill.
 
 ## Miscellaneous
 

MIGRATING.md

@@ -0,0 +1,27 @@
+# Migrating
+
+## Version 3 to 4
+
+Version 4 restructures the library's exports to have more modern defaults, and employs modern best practices for publishing npm packages.
+
+* The default export (i.e. `import "web-streams-polyfill"`) is now the *ponyfill* variant instead of the *polyfill* variant, to avoid modifying the global scope. If you do want to install the polyfill on the global scope, switch to
+  the `polyfill` variant.
+* The default export uses ES2015 syntax and targets modern Node and browser environments. If you need to support ES5 environments, switch to either the `es5` or `polyfill/es5` variant.
+* The polyfill variant no longer re-exports the ponyfill, so `import { ReadableStream } from "web-streams-polyfill/polyfill"` won't work. Instead, use the global `ReadableStream` variable directly after loading the polyfill, or switch to the default (non-polyfill) variant.
+* The project uses [Node's subpath exports](https://nodejs.org/api/packages.html#packages_package_entry_points) to provide each variant as a [dual module (UMD/ESM)](https://nodejs.org/api/packages.html#packages_dual_commonjs_es_module_packages). You need Node 12.20.0 or higher to resolve these variants. If you're using a bundler (like webpack or Rollup), you need to make sure it's up-to-date too. If you're using TypeScript, your [`moduleResolution`](https://www.typescriptlang.org/tsconfig#moduleResolution) must be set to `"node16"`, `"nodenext"` or `"bundler"`.
+
+Version 4 also focuses on reducing the download size of the published npm package.
+
+* All published JavaScript code is now minified, without source maps. If you need to debug the polyfill, you can [clone it](/~https://github.com/MattiasBuelens/web-streams-polyfill) and [build it yourself](/~https://github.com/MattiasBuelens/web-streams-polyfill/blob/master/CONTRIBUTING.md).
+* The ES2018 variant was removed, since it had only minor differences with the ES2015 variant. If you were using this variant, switch to the default export instead.
+
+The following table shows how to upgrade your v3 import to their equivalent v4 import:
+
+| v3 import | v4 import | description |
+| --- | --- | --- |
+| `web-streams-polyfill` | `web-streams-polyfill/polyfill/es5` | ES5+ polyfill |
+| `web-streams-polyfill/es6` | `web-streams-polyfill/polyfill` | ES2015+ polyfill |
+| `web-streams-polyfill/es2018` | `web-streams-polyfill/polyfill` | ES2015+ polyfill |
+| `web-streams-polyfill/ponyfill` | `web-streams-polyfill/es5` | ES5+ ponyfill |
+| `web-streams-polyfill/ponyfill/es6` | `web-streams-polyfill` | ES2015+ ponyfill |
+| `web-streams-polyfill/ponyfill/es2018` | `web-streams-polyfill` | ES2015+ ponyfill |

README.md

@@ -14,70 +14,80 @@ Web Streams, based on the WHATWG spec reference implementation.
 ## Usage
 
 This library comes in multiple variants:
-* `web-streams-polyfill`: a polyfill that replaces the native stream implementations.
-  Recommended for use in web apps supporting older browsers through a `<script>` tag.
-* `web-streams-polyfill/es6`: a polyfill targeting ES2015+ environments.
-  Recommended for use in web apps supporting modern browsers through a `<script>` tag.
-* `web-streams-polyfill/es2018`: a polyfill targeting ES2018+ environments.
-* `web-streams-polyfill/ponyfill`: a [ponyfill] that provides
-  the stream implementations without replacing any globals.
-  Recommended for use in legacy Node applications, or in web libraries supporting older browsers.
-* `web-streams-polyfill/ponyfill/es6`: a ponyfill targeting ES2015+ environments.
+* `web-streams-polyfill`: a [ponyfill] that provides the stream implementations 
+  without replacing any globals, targeting ES2015+ environments.
   Recommended for use in Node 6+ applications, or in web libraries supporting modern browsers.
-* `web-streams-polyfill/ponyfill/es2018`: a ponyfill targeting ES2018+ environments.
-  Recommended for use in Node 10+ applications.
+* `web-streams-polyfill/es5`: a ponyfill targeting ES5+ environments.
+  Recommended for use in legacy Node applications, or in web libraries supporting older browsers.
+* `web-streams-polyfill/polyfill`: a polyfill that replaces the native stream implementations,
+  targeting ES2015+ environments.
+  Recommended for use in web apps supporting modern browsers through a `<script>` tag.
+* `web-streams-polyfill/polyfill/es5`: a polyfill targeting ES5+ environments.
+  Recommended for use in web apps supporting older browsers through a `<script>` tag.
 
 Each variant also includes TypeScript type definitions, compatible with the DOM type definitions for streams included in TypeScript.
+These type definitions require TypeScript version 4.7 or higher.
+
+In version 4, the list of variants was reworked to have more modern defaults and to reduce the download size of the package.
+See the [migration guide][migrating] for more information.
 
 Usage as a polyfill:
 ```html
 <!-- option 1: hosted by unpkg CDN -->
-<script src="https://unpkg.com/web-streams-polyfill/dist/polyfill.min.js"></script>
+<script src="https://unpkg.com/web-streams-polyfill/dist/polyfill.js"></script>
 <!-- option 2: self hosted -->
-<script src="/path/to/web-streams-polyfill/dist/polyfill.min.js"></script>
+<script src="/path/to/web-streams-polyfill/dist/polyfill.js"></script>
 <script>
 var readable = new ReadableStream();
 </script>
 ```
 Usage as a Node module:
 ```js
-var streams = require("web-streams-polyfill/ponyfill");
+var streams = require("web-streams-polyfill");
 var readable = new streams.ReadableStream();
 ```
-Usage as a ES2015 module:
+Usage as a ponyfill from within a ES2015 module:
+```js
+import { ReadableStream } from "web-streams-polyfill";
+const readable = new ReadableStream();
+```
+Usage as a polyfill from within an ES2015 module:
 ```js
-import { ReadableStream } from "web-streams-polyfill/ponyfill";
+import "web-streams-polyfill/polyfill";
 const readable = new ReadableStream();
 ```
 
 ## Compatibility
 
-The `polyfill` and `ponyfill` variants work in any ES5-compatible environment that has a global `Promise`.
+The `polyfill` and `ponyfill` variants work in any ES2015-compatible environment.
+
+The `polyfill/es5` and `ponyfill/es5` variants work in any ES5-compatible environment that has a global `Promise`.
 If you need to support older browsers or Node versions that do not have a native `Promise` implementation
 (check the [support table][promise-support]), you must first include a `Promise` polyfill
 (e.g. [promise-polyfill][promise-polyfill]).
 
-The `polyfill/es6` and `ponyfill/es6` variants work in any ES2015-compatible environment.
-
-The `polyfill/es2018` and `ponyfill/es2018` variants work in any ES2018-compatible environment.
-
 [Async iterable support for `ReadableStream`][rs-asynciterator] is available in all variants, but requires an ES2018-compatible environment or a polyfill for `Symbol.asyncIterator`.
 
 [`WritableStreamDefaultController.signal`][ws-controller-signal] is available in all variants, but requires a global `AbortController` constructor. If necessary, consider using a polyfill such as [abortcontroller-polyfill].
 
 [Reading with a BYOB reader][mdn-byob-read] is available in all variants, but requires `ArrayBuffer.prototype.transfer()` or `structuredClone()` to exist in order to correctly transfer the given view's buffer. If not available, then the buffer won't be transferred during the read.
 
+### Tooling compatibility
+
+This package uses [subpath exports](https://nodejs.org/api/packages.html#subpath-exports) for its variants. As such, you need Node 12 or higher in order to `import` or `require()` such a variant.
+
+When using TypeScript, make sure your [`moduleResolution`](https://www.typescriptlang.org/tsconfig#moduleResolution) is set to `"node16"`, `"nodenext"` or `"bundler"`.
+
 ## Compliance
 
 The polyfill implements [version `4dc123a` (13 Nov 2023)][spec-snapshot] of the streams specification.
 
 The polyfill is tested against the same [web platform tests][wpt] that are used by browsers to test their native implementations.
 The polyfill aims to pass all tests, although it allows some exceptions for practical reasons:
-* The `es2018` variant passes all of the tests.
-* The `es6` variant passes the same tests as the `es2018` variant, except for the [test for the prototype of `ReadableStream`'s async iterator][wpt-async-iterator-prototype].
+* The default (ES2015) variant passes all of the tests, except for the [test for the prototype of `ReadableStream`'s async iterator][wpt-async-iterator-prototype].
   Retrieving the correct `%AsyncIteratorPrototype%` requires using an async generator (`async function* () {}`), which is invalid syntax before ES2018.
   Instead, the polyfill [creates its own version][stub-async-iterator-prototype] which is functionally equivalent to the real prototype.
-* The `es5` variant passes the same tests as the `es6` variant, except for various tests about specific characteristics of the constructors, properties and methods.
+* The ES5 variant passes the same tests as the ES2015 variant, except for various tests about specific characteristics of the constructors, properties and methods.
   These test failures do not affect the run-time behavior of the polyfill.
   For example:
   * The `name` property of down-leveled constructors is incorrect.
@@ -97,6 +107,7 @@ Thanks to these people for their work on [the original polyfill][creatorrr-polyf
 [spec]: https://streams.spec.whatwg.org
 [ref-impl]: /~https://github.com/whatwg/streams
 [ponyfill]: /~https://github.com/sindresorhus/ponyfill
+[migrating]: /~https://github.com/MattiasBuelens/web-streams-polyfill/blob/v4/MIGRATING.md
 [promise-support]: https://kangax.github.io/compat-table/es6/#test-Promise
 [promise-polyfill]: https://www.npmjs.com/package/promise-polyfill
 [rs-asynciterator]: https://streams.spec.whatwg.org/#rs-asynciterator

api-extractor.json

@@ -45,7 +45,7 @@
    *
    * SUPPORTED TOKENS: <projectFolder>, <packageName>, <unscopedPackageName>
    */
-  "mainEntryPointFilePath": "<projectFolder>/lib/polyfill.d.ts",
+  "mainEntryPointFilePath": "<projectFolder>/lib/ponyfill.d.ts",
 
   /**
    * A list of NPM package names whose exports should be treated as part of this package.
@@ -195,7 +195,7 @@
      * SUPPORTED TOKENS: <projectFolder>, <packageName>, <unscopedPackageName>
      * DEFAULT VALUE: "<projectFolder>/dist/<unscopedPackageName>.d.ts"
      */
-    "untrimmedFilePath": "<projectFolder>/dist/types/ts3.6/ponyfill.d.ts",
+    "untrimmedFilePath": "<projectFolder>/types/ponyfill.d.ts",
 
     /**
      * Specifies the output path for a .d.ts rollup file to be generated with trimming for a "beta" release.
@@ -256,7 +256,7 @@
      * SUPPORTED TOKENS: <projectFolder>, <packageName>, <unscopedPackageName>
      * DEFAULT VALUE: "<lookup>"
      */
-    "tsdocMetadataFilePath": "<projectFolder>/dist/types/tsdoc-metadata.json"
+    "tsdocMetadataFilePath": "<projectFolder>/types/tsdoc-metadata.json"
   },
   /**
    * Specifies what type of newlines API Extractor should use when writing output files.  By default, the output files