v4.0.0

• 💥 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 for more information. (#82, #139)
• 💥 Remove the ES2018 variant, in favor of the ES2015 variant.
• 💥 Switch to 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 must be set to "node16", "nodenext" or "bundler".
• 🚀 Support importing as ESM in Node.
• 💅 Minify all code in the published package, to reduce the download size.
• 💅 Rework ReadableStream.from() implementation to avoid depending on async function* down-leveling for ES5. (#144)

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

v3.3.3

• 🐛 Fix ReadableStream to match TypeScript's AsyncIterable<R> type. (#141, #142)

v3.3.2

• 🐛 Fix bad publish to npm.

v3.3.1

• 🐛 Revert engines bump in package.json. (#137, #138)
• 🐛 Re-introduce support for TypeScript 3.5 and below. (#137, #138)

v3.3.0

• 🚀 Added global augmentations for ReadableStream to the polyfill's type definitions. (#130)
  • This allows TypeScript users to use new methods such as ReadableStream.prototype[Symbol.asyncIterator](), even when TypeScript doesn't yet have a built-in type definition for them.
• 💥 The type definitions now require TypeScript 3.6 or higher. (#130) (Reverted in version 3.3.1)
• 👓 Align with spec version 4dc123a (#115, #134)
  • Added ReadableStream.from(asyncIterable), which creates a ReadableStream wrapping the given iterable or async iterable. This can also be used to wrap a native ReadableStream (e.g. a Response.body from fetch()), even if the native ReadableStream doesn't yet support async iteration. (#135)
  • Added Transformer.cancel method, which is called when the readable side of a TransformStream is cancelled or when its writable side is aborted.
  • Added min option to ReadableStreamBYOBReader.read(view, options).
  • Added support for AbortSignal.reason when aborting a pipe.
• 🚀 Buffers passed to ReadableStreamBYOBReader.read(view) will now be correctly transferred if either ArrayBuffer.prototype.transfer() or structuredClone() is available. (#136)
• 🐛 Prevent warnings from Bluebird about a promise being created within a handler but not being returned from a handler. (#131)
• 🏠 Improve internal DOMException polyfill. (#133)

v4.0.0-beta.3

• 👓 Align with spec version e9355ce. (#115, #117)
• 🐛 Fix pipeTo() never rejecting when aborting its signal and preventCancel is set to true. (#118, #119)

v4.0.0-beta.2

• 🚀 Support calling ReadableStream.pipeTo(writable) and .pipeThrough({ readable, writable }) when writable is a native (i.e. not polyfilled) WritableStream. (#99, #101)
• 💅 Add fallback for package exports for backwards compatibility with older Node versions. (#107)
• 🐛 Prevent warnings from Bluebird about a promise being created within a handler but not being returned from a handler. (#91)

v3.2.1

• 🐛 Fix an error in very old browsers where Function.name is non-configurable. (#112)

v3.2.0

• 👎 Deprecate WritableStreamDefaultController.abortReason (#102)
  • Use WritableStreamDefaultController.signal.reason instead.
• 👓 Align with spec version 4b6b93c (#103)

v4.0.0-beta.1

• 💥 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 for more information.
  (#82, #83)
• 💥 Remove the ES2018 variant, in favor of the ES2015 variant.
• 🚀 Support importing as ESM in Node.
• 💅 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