Malte UblandClaude Opus 5.5 34eef83ef4 Decide concat spreading of dynamic values at run time; keep JS lets assigned from index reads unchecked ...

Three JavaScript lowering bugs threw a checked conversion where Node answers:

- concat with a checked-dynamic argument lowered it as an element, so an
  array argument threw. The argument now spreads when it is an array at run
  time and is appended otherwise.
- `let c; while ((c = str[i++]) !== "]" && c)`: the checker types c from the
  index read, without the undefined a read past the end answers. Evolving-let
  inference ignores index-read writes, and reads of a JS `let x;` statement
  binding keep the actual value.
- Strict equality on a flow-narrowed dynamic JS name compares unchecked.

npm cases concat-dynamic-args and evolving-let-index match Node.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

2026-10-25 09:19:53 -07:00

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corpus

Use fixed timestamps in the fs.cp preserveTimestamps test (#2136)

2026-10-24 15:01:18 -05:00

coverage-fixtures

Merge main

2026-10-23 05:57:14 -05:00

deadstrip

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diagnostics

zlib: Brotli compression and decompression over the vendored brotli 1.2.0 (#2053)

2026-10-24 00:30:21 -05:00

ffi

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fixtures

Decide concat spreading of dynamic values at run time; keep JS lets assigned from index reads unchecked

2026-10-25 09:19:53 -07:00

harness

Cut the shape overlay's compile cost; keep package JSDoc it does not replace

2026-10-25 07:34:05 -07:00

library-mode

Cache untyped property access in programs that declare classes (reland)

2026-10-24 08:22:30 -05:00

test262

Run Test262 tests that include testTypedArray.js

2026-10-23 14:27:20 -05:00

wasm-spec

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