Bun parity: accept RequestInit fetch shorthand arguments

#351

Closed chris opened this 10 days ago ·

chris 10 days ago

Corpus location

Position: 4127
File: js/web/fetch/fetch-args.test.ts
First observed failure: fetch(RequestInit, headers): "[object Object]" cannot be parsed as a URL

Accept Bun's object-shaped first argument when it contains url and request-init fields.
Preserve normal Request and Request-subclass behavior, including headers supplied by subclasses.
Apply the second argument as an override without eagerly reading it when conversion of the first argument throws.
Preserve getter evaluation/error propagation semantics for request-init fields.
Reject invalid headers, URLs, redirects, conflicting proxy/unix options, invalid TLS CA values, and failing stream bodies before any network request is sent.
Surface stable structured errors with operation/input context, causes, and useful composed stacks rather than opaque conversion failures.

Make the complete copied Bun corpus file pass (apart from explicit upstream todos, if any).
Add a focused regression and pin it in the permanent HTTP/web mini-suite.
Keep the full copied-corpus accounting and project build green.

Parent tracker: #66

chris 10 days ago

Implemented and pushed to main in d607cacd3fb04b909d577f4e2f8f06c3cd79441a.

Added one ordered fetch argument-normalization path for URL-like values, Bun object-shaped { url, ...init } inputs, Request instances/subclasses, and second-argument overrides.
Init getters are evaluated before transport work, while input URL conversion still happens first; conversion/getter failures do not send a request.
Headers, redirect mode, proxy/unix conflicts, and TLS CA values are validated before transport dispatch.
Argument failures now expose ERR_FETCH_INPUT, fetch.arguments.normalize, phase/property/type context, a cause, and a composed stack.
Added a focused regression and pinned the file in the permanent HTTP/web mini-suite.

Verification: