Major Changes

• #349 b195e70 Thanks @rexxars! - - BREAKING CHANGE: The client now fails the connection, emitting an error without reconnecting, if the parser buffers 100 MB without receiving a valid, complete EventSource line. Configure a different limit with maxBufferSize; ideally, servers should emit smaller chunks or newlines more frequently.
  • BREAKING CHANGE: Node.js 22.12 or later is now required. Older Node.js versions may still work, but are not supported or guaranteed going forward because Node.js 20 is out of LTS.
  • BREAKING CHANGE: The separate CommonJS variant is no longer published. Node.js 22.12 and later transparently supports require() of ESM, so most CommonJS consumers should continue to work. This removes the dual-package hazard.
  • BREAKING CHANGE: Chrome versions before 84, Safari before 15, Firefox before 105, Edge before 84, and JavaScript environments without private fields, methods, and accessors are no longer supported.
  • BREAKING CHANGE: When both an on* property handler and an addEventListener() listener are registered for the same event, they now run in registration order instead of always running the on* handler first. Code that relied on the old order can observe a different callback sequence.
  • Unref reconnection timers where the runtime supports it, so pending reconnects do not keep the process alive.

Patch Changes

• #351 6127f40 Thanks @rexxars! - Allow a value of any type in ReaderLike done-results. TypeScript 5.9's DOM lib types ReadableStreamDefaultReader.read()'s done-result as {done: true, value: T | undefined}, so a custom fetch returning a Response-shaped body no longer satisfied FetchLikeResponse on TypeScript 5.9 and newer, forcing consumers to hand-wrap the reader.

4.1.0 (2025-11-19)

Features

• declare fetch override support symbol on class (5575122)

This release is also available on:

• npm package (@latest dist-tag)

4.0.0 (2025-05-13)

⚠ BREAKING CHANGES

• FetchLikeInit is now removed. Use
  EventSourceFetchInit.
• Drop support for Node.js v18, as it is end-of-life.

Features

• require node.js v20 or higher (91a3a48)

Bug Fixes

• drop FetchLikeInit type. Use EventSourceFetchInit instead. (6786e46)

This release is also available on:

• npm package (@latest dist-tag)

3.0.7 (2025-05-09)

Bug Fixes

• mark fetch init properties required in typings (1282872)

This release is also available on:

• npm package (@latest dist-tag)

3.0.6 (2025-03-27)

Bug Fixes

• upgrade parser to latest version, improving performance (59a5ddd)

This release is also available on:

• npm package (@latest dist-tag)

3.0.5 (2025-01-28)

Bug Fixes

• include message and code on errors when logging in node.js and deno (f2596b3)

This release is also available on:

• npm package (@latest dist-tag)

3.0.4 (2025-01-28)

Bug Fixes

• ensure message is set on ErrorEvent on network errors (d1dc711)

This release is also available on:

• npm package (@latest dist-tag)

3.0.3 (2025-01-27)

Bug Fixes

• bundle event listener typings (2c51349)

This release is also available on:

• npm package (@latest dist-tag)

3.0.2 (2024-12-13)

Bug Fixes

• reference possibly missing event typings (d3b6849)

This release is also available on:

• npm package (@latest dist-tag)