Fetch Request Streaming

[dandclark]

Description

Fetch request streaming allows developers to create a fetch request with a ReadableStream body. This can be used for uploading streaming data, or for talking to a streaming endpoint without requiring an intermediary.

Tests: https://wpt.fyi/results/fetch/api/basic?label=experimental&label=master&aligned&q=fetch%2Fapi%2Fbasic%2Frequest-upload

Specification

https://fetch.spec.whatwg.org/#concept-body-stream

Additional Signals

• Upvoted responses at https://stackoverflow.com/questions/35711724/upload-progress-indicators-for-fetch discussing fetch upload streaming
• Many positive developer comments on Uploading a Request made from a ReadableStream body whatwg/fetch#425
• Use cases discussed by developers at https://groups.google.com/a/chromium.org/g/blink-network-dev/c/bsVgOxNCzFc
• 73 +1s on https://issues.chromium.org/issues/40505032