mirror of
https://github.com/hanzoai/react.git
synced 2026-08-07 11:24:42 +00:00
5a90a5a7a5
## Summary
The compiler silently rewrote functions containing `using` and `await
using` declarations (explicit resource management). BuildHIR's
`VariableDeclaration` case only special-cases `var`; every other kind
falls through to `InstructionKind.Const`. A `using` declaration
therefore compiled as a plain memoized `const`, and the implicit dispose
call at scope exit was dropped from the compiled output. No diagnostic
was emitted. The Rust port mirrored the same bug in `build_hir.rs`.
The Rust port had a second, harder failure: its
`VariableDeclarationKind` enum had no `await using` variant, so a Babel
AST containing one failed serde deserialization at the NAPI boundary
("unknown variant `await using`") and threw for the whole file.
The fix records the same per-function Todo bail as the existing `var`
case, in both implementations, then continues lowering the declaration
as `const` so references do not break while the error unwinds (mirroring
how `var` continues as `let`). This matches the compiler's established
Todo-bail precedent for unsupported syntax: the function is skipped with
a logged `CompileError` diagnostic, `panicThreshold` is respected, and
sibling functions in the same file still compile. This deliberately
contrasts with oxc-project/oxc#24217, which handles the same syntax with
a silent per-function skip; nothing in this compiler is skipped without
a surfaced diagnostic.
Changes:
- TS: `BuildHIR.ts` records a Todo `CompilerErrorDetail` for `using` and
`await using` kinds, in the style of the existing `var` case.
- Rust: same Todo `record_error` in `build_hir.rs`. New `AwaitUsing`
variant (serde name `"await using"`) in `react_compiler_ast`, so `await
using` survives the NAPI boundary, covered by a serde round-trip unit
test.
- Test harness: enables the `explicitResourceManagement` parser plugin
in snap and in the e2e script's Babel baseline so fixtures can use the
syntax.
Fixtures (identical snapshots for the TS and Rust pipelines):
- `error.todo-using-declaration` and
`error.todo-await-using-declaration` show the Todo diagnostic with code
frames.
- `using-declaration-bailout-sibling-compiles` shows the bailing
function left untouched (disposal preserved) while a sibling component
in the same file is memoized.
The first commit snapshots the previous broken behavior (`using`
memoized as `const` with disposal dropped); the second commit lands the
fix and updates the snapshots.
## How did you test this change?
All results below are from the branch rebased onto current main.
TS implementation:
- `yarn snap`: 1809 tests, 1809 passed, 0 failed.
- `yarn workspace babel-plugin-react-compiler lint`: clean. `yarn
prettier-check` at the repo root: clean.
- Manually verified pre-fix output: a component with `using resource =
getResource(props.id)` compiled to a memoized `const` with no disposal.
Rust implementation:
- `cargo test --workspace`: 42 passed, 0 failed (includes the new serde
round-trip unit test for both `using` kinds).
- `bash scripts/test-babel-ast.sh`: passed.
- `bash scripts/test-rust-port.sh`: 1808 passed, 0 failed.
- `yarn snap --rust`: 1809 tests, 1809 passed, 0 failed, against the
same `.expect.md` snapshots as the TS run.
- `scripts/test-e2e.ts` (babel variant): the three using fixtures pass
code and events parity.
- Manually verified `await using` now deserializes across the NAPI
boundary and records the Todo instead of throwing.
<div><a
href="https://cursor.com/agents/bc-5fe4350d-5d42-4c0e-9001-429ed0b5e5b7"><picture><source
media="(prefers-color-scheme: dark)"
srcset="https://cursor.com/assets/images/open-in-web-dark.png"><source
media="(prefers-color-scheme: light)"
srcset="https://cursor.com/assets/images/open-in-web-light.png"><img
alt="Open in Web" width="114" height="28"
src="https://cursor.com/assets/images/open-in-web-dark.png"></picture></a> <a
href="https://cursor.com/background-agent?bcId=bc-5fe4350d-5d42-4c0e-9001-429ed0b5e5b7"><picture><source
media="(prefers-color-scheme: dark)"
srcset="https://cursor.com/assets/images/open-in-cursor-dark.png"><source
media="(prefers-color-scheme: light)"
srcset="https://cursor.com/assets/images/open-in-cursor-light.png"><img
alt="Open in Cursor" width="131" height="28"
src="https://cursor.com/assets/images/open-in-cursor-dark.png"></picture></a> </div>
---------
Co-authored-by: Cursor Agent <cursoragent@cursor.com>
