Fix tokens produced when `<<` opens a type argument list. e.g.:
```typescript
type Bar = ReturnType<<T>(x: T) => number>;
```
Previously only 1 `<` token was produced between `ReturnType` and `T`. This PR corrects that so 2 `<` tokens are produced.
TS-ESLint get this wrong too - hence why this wasn't noticed before, as our conformance tests compare to TS-ESLint.
PR submitted to fix TS-ESLint: https://github.com/typescript-eslint/typescript-eslint/pull/12821
In meantime, this PR skips the erroneously failing ESTree tokens conformance tests. We can can re-enable those tests once the fix lands in TS-ESLint.
## Summary
- update workspace test dependencies to Vitest 5.0.0
- pin Vitest and related tooling to Vite 8.2.2
- migrate removed sequential and benchmark APIs
- update the pnpm lockfile
#26263 added the ability to run tests and conformance for both versions of `oxc_lexer` (SIMD and scalar fallback) on any platform.
Run tests and conformance on CI (both SIMD and scalar) on any PR which touches `oxc_lexer` crate or other files which affect conformance runner.
Additionally, run Clippy on the SIMD version (main Lint CI task doesn't lint it, due to the `target_feature = "avx2"` gate on the code).
All of this sets up `oxc_lexer` crate for further development, catching any regressions in CI.
`oxc_lexer` has 2 implementations:
1\. SIMD-based on x86_64 with AVX2.
2\. Scalar/SWAR fallback which works on all platforms.
Both produce the same output.
This PR enables running the lexer conformance on either implementation. Which implementation is tested depends on what build flags are passed to `cargo coverage`.
It turns out that it's possible to test the SIMD implementation on Mac by compiling as x86_64, and running it under Rosetta 2.
This PR also adds `just` recipes to run tests and conformance on either implementation:
- `just test-lexer`
- `just test-lexer-simd`
- `just conformance-lexer`
- `just conformance-lexer-simd`
These commands should work correctly on any of Linux x86, Windows x86, Mac aarch64.
Refactor the conformance tester for lexer.
The diff is large, as I've reordered the code so it now reads top-to-bottom, but it's pure refactor. The actual logic is exactly as it was before - just moved things around, renamed vars, shortened code etc.
This also fixes some Clippy warnings which were present before, but hidden because this code is gated behind `target_feature = "avx2"`. That changes in next PR #26263, at which point CI would have started failing if the warnings weren't fixed here first.
Small fix to `cargo coverage`.
Previously a typo e.g. `cargo coverage prser` would fall through to the catch-all arm and would run all coverage tasks.
Instead, this PR makes it panic with an error `Unknown coverage task: "prser"`. This ensures you are running what you think you are.
Conformance tests for `oxc_lexer` crate rely on using `catch_unwind` to catch panics and report them, rather than crashing the whole process. Currently this doesn't work because conformance is compiled with `panic = "abort"` (inherited from `release` profile).
This PR fixes that by adding `panic = "unwind"` to `coverage` profile.
I've measured the time it takes to run conformance locally before/after this change, and the difference is within noise (+/- 2%), so this seems to have no adverse effects.
`codegen-conformance` profile only existed to add `panic = "unwind"` too, so after this change it becomes identical to `coverage` profile. That makes it redundant, so this PR removes it in favour of just using `coverage` everywhere.
When the parser records a fatal error it fast-forwards the lexer to end of file. `re_lex_template_substitution_tail` did not check for that, so an incomplete template substitution would still re-lex the `}` and derive the token's start from a cursor which had already jumped to the end.
With tokens enabled, that fails the debug assertion in `finish_next_inner`, because the token being replaced is no longer the one on top of the collected token stream. Release builds silently overwrite an unrelated token instead. Tokens are only collected for Oxlint's JS plugins, which bail out if any parsing error, which is why this hadn't been noticed before.
Fix by adding the same `fatal_error` guard, added to other re-lex methods in #11023.
This does make a difference to diagnostics output for invalid code matching this pattern. TypeScript snapshot loses an "Unterminated string" diagnostic on 2 fixtures. Those errors came from the bogus re-lex reading past end of file. Both these fixtures already have an "Unexpected token" error. The additional "Unterminated string" errors were incorrect, and this fix has the side effect of removing them.
Updates the minifier documentation to use supported validation commands and fixes broken relative links. Also refreshes the coverage task README so it no longer advertises removed suite selectors.
## Summary
- add `GetNodeId` alongside `NodeId` in `oxc_syntax`
- add a dedicated `DeriveGetNodeId` following the existing `GetSpan` derive architecture
- generate implementations into `derive_get_node_id.rs`, delegating uniformly through `self.node_id()`
```js
// input (semi: true)
// oxfmt-ignore
const a = x
// before
// oxfmt-ignore
const a = x
// after
// oxfmt-ignore
const a = x;
```
```js
// input (semi: false)
let a = 1;
// oxfmt-ignore
[b].sort();
// before
let a = 1
// oxfmt-ignore
[b].sort(); // <- ASI failure
// after
let a = 1
// oxfmt-ignore
;[b].sort() // <- OK
```
Fixes#26165
- `side_effect` is predefined selector, it cannot be used as custom group name
- respect custom group which uses `side_effect` as side-effect-import correctly
- fix metadata detection bug
improve negation of 1 and 0 to 0 and 1 in boolean context
previously only `!!0` and `!!1` could be inlined to `1` and `0` and now
`!0` and `!1` will also be inlined,
this change allows us to flip numeric values in-place instead of having
to first to create unary and remove it afterwards
```
!0 was converted before to 1 in some cases:
1. negate 1
2. !1 - add unary
3. 0 - remove unary
now:
1. negate 1
2. 0
```
expands leading assignment inlining into variable declarations for
`return`, `switch`, `if`, `throw`, `for`, `for in`, `for of`
```js
// return
var a; return a = b(), c;
var a = b(); return c;
// throw
var a; throw a = b(), c;
var a = b(); throw c;
// switch
var a; switch (a = b(), c) {}
var a = b(); switch (c) {}
// for
var a; for (a = b(), c; ;) d;
var a = b(); for (c; ;) d;
// if
var a; if (a = b(), c) d;
var a = b(); if (c) d;
```
fixes#25949
## Summary
- follow chained labels to their terminal statement when validating labeled `continue`
- reject label chains that terminate in a non-iteration statement
- add a focused negative coverage fixture and update the parser coverage snapshot
Expand negation to include move of `!` operator to inner children
```js
!(a == b && c == 3 && a)
a != b || c != 3 | !a
```
delta calculation is dependent on boolean context
- if we expect truthly/falsly value negation of `!a` will be converted
to `a` (-1 delta)
- in ambiguous context `!a` will be converted to `!!a` (+1 delta)
```js
a = !!(!b || !c);
// ^ ^ ^ -3
a = !(b || c)
// ^ ^ ^ +1 - if we could detect if parens can be removed it would be -1
// ^^^ ^^ -1 - if we would know that we can remove parens
```
## Summary
Fix ES2018 object-rest lowering when one variable declaration contains multiple object-rest declarators.
### Before
Given:
```js
let { a, ...r } = x, { b, ...s } = y;
```
Oxc produced:
```js
let { a } = x, { b } = y,
s = babelHelpers.objectWithoutProperties(y, ["b"]),
{} = null;
```
The `r` binding was lost.
Each replacement was recorded using its original declarator index. Replacing the first declarator expanded it into multiple entries, shifting the second declarator. The subsequent replacement still used the old index and overwrote part of the first expansion.
### After
Oxc now produces:
```js
let { a } = x,
r = babelHelpers.objectWithoutProperties(x, ["a"]),
{ b } = y,
s = babelHelpers.objectWithoutProperties(y, ["b"]);
```
Queued replacements are applied from right to left. Replacing a later declarator cannot change the index of an earlier one, so every recorded index remains valid.
Regression coverage includes multiple `let`, `const`, and `var` declarators.
## Summary
Fix a parser panic when a string-named export decodes to a literal `\u` sequence.
Lone-surrogate validation now uses the metadata captured by the lexer instead of rescanning decoded string contents. This also prevents false diagnostics for names such as `"\\uD800"`.
## Before:
```
thread 'main' (10990283) panicked at crates/oxc_ast/src/ast_impl/literal.rs:89:42:
end byte index 4 is out of bounds for string of length 0
stack backtrace:
0: __rustc::rust_begin_unwind
1: core::panicking::panic_fmt
2: core::str::slice_error_fail_rt
3: core::str::slice_error_fail
4: <core::ops::range::RangeTo<usize> as core::slice::index::SliceIndex<str>>::index
5: <str as core::ops::index::Index<core::ops::range::RangeTo<usize>>>::index
6: <oxc_ast::ast::literal::StringLiteral>::is_string_well_formed_unicode
7: <oxc_parser::ParserImpl<oxc_parser::config::NoTokensParserConfig>>::parse_module_export_name
```
Function parameters, TypeScript signatures, and function bodies currently share one Oxc semantic scope. A reference in a parameter can therefore bind to a declaration inside the body, even though JavaScript does not make body declarations visible there. Rolldown may then treat a global as local, skip a configured define, or remove live code.
## Example
```js
export function load(value = typeof window !== "undefined") {
var window;
return value;
}
```
The body `var window` is not visible to the default value. Before this change, Oxc resolved `window` in the default value to that body declaration. It should remain a global reference.
The workaround resolves parameter and signature references before visiting the body, while only parameter bindings are present. If a reference is still unresolved, its `lookup_scope_id` advances to the function's parent. Final resolution resumes there, so declarations added while visiting the body are skipped. References created in the body still begin at the function scope and resolve normally.
```text
Before: parameter reference -> completed function scope -> body binding (wrong)
After: parameter reference -> parameter bindings -> parent scopes
body reference -> completed function scope -> parent scopes
```
Parameter decorators already begin in the enclosing class scope, so they are left for normal final resolution. This emulates separate parameter and body scopes until https://github.com/oxc-project/backlog/issues/176 is implemented.
The corrected semantic data also exposes the transformer case covered by #26105.
Verified with semantic and transformer-plugin tests, Clippy, coverage, allocation snapshots, and diff checks. `just ready` completed workspace checks but stopped at a codegen snapshot recorded with Node.js v26.5.0; the local version is v25.8.1.
Closes#20427Closes#22783
Downstream reports:
- https://github.com/rolldown/rolldown/issues/10722
- https://github.com/rolldown/rolldown/issues/10779
AI assistance: OpenAI Codex was used to investigate, implement, and test this change. The contributor is responsible for the submitted change.
Fixes#26113.
The rule was moved from the TypeScript plugin to the ESLint plugin in 79fc6d7e9f, but its TypeScript-only execution gate was retained. As a result, eslint/no-use-before-define never ran for JavaScript or JSX files.Remove the gate and add a JavaScript regression test for a temporal-dead-zone reference.
Fixes#25911
---
As syntax, these two forms are equivalent:
```ts
@deco export class X {}
export @deco class X {}
```
However, in the former, the decorators lie outside the span of both the `ExportDeclaration` and the `Class`, they are inside no node's span.
The formatter's suppression path prints the `ExportDeclaration`'s span verbatim, so the decorators were silently dropped.
The latter form is unaffected because the decorators fall inside the export node's span.
Serialize `FormalParameterRest` with its outer span so its range includes parameter decorators. Regenerate the raw-transfer deserializers and remove `sourceMapValidationDecorators.ts` from the ESTree mismatch baseline.
Fixes#26011.
Move removal of dead code from switch stmts to remove_dead_code, this
change enables processing of switch stmts whose parent is not list of
stmts
current minification processes stmts whose parents are block stmts and
they are last stmt of set block, this change also allows us to remove
empty blocks and last break from switch cases whose parent is not block
stmt
```js
if (a) { b(); if (c) switch (d) { case 1: case 2: break; } c(); }
// ^~~~~~ due to body not being a block we where not able to process this
// Current:
if (a) { if (b(), c) switch (d) { case 1: case 2: break } c() }
// ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ this switch case is not being processed
// This branch:
a && (b(), c && d, c());
// ^ switch cases can be correctly processed
```
note: this change applies only dce, and dosn't substitute switch stmts
with if'stmts
#### changes in stack:
- https://github.com/oxc-project/oxc/pull/25405
- https://github.com/oxc-project/oxc/pull/25403👈
- `main`
Addresses deprecations reported by the latest Rust nightly while preserving Rust 1.98 compatibility.
- Rename `unit-bindings` to `unit_bindings`: hyphenated lint names are deprecated in favor of their canonical underscore spelling.
- Replace `isize::max_value()` and `usize::max_value()` with `isize::MAX` and `usize::MAX`: the legacy numeric methods are deprecated in favor of associated constants.
- Set explicit `MAX_INDEX` values on `define_index_type!`: `oxc_index` otherwise generates `<raw>::max_value() as usize`; the explicit modern constants avoid that deprecated expansion without changing the index limits.
- Remove obsolete `clippy::legacy_numeric_constants` expectations: the corrected code no longer triggers that lint, so the expectations would be unfulfilled.
- Allow the AST scanner to consume optional `define_index_type!` configuration: it previously parsed only the struct declaration and rejected the added `MAX_INDEX` option.
AI-assisted.
## Summary
- bump the workspace MSRV from 1.95.0 to 1.96.0 under the N-2 policy after #25945
- retain an MSRV-compatible layout calculation while suppressing the Rust 1.98 Clippy suggestion
This PR contains the following updates:
| Package | Type | Update | Change |
|---|---|---|---|
| [rust](https://rust-lang.org/)
([source](https://redirect.github.com/rust-lang/rust),
[changelog](https://redirect.github.com/rust-lang/rust/blob/main/RELEASES.md))
| toolchain | minor | `1.97.1` → `1.98.0` |
---
### Configuration
📅 **Schedule**: (in timezone Asia/Shanghai)
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- "before 10am on monday"
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🚦 **Automerge**: Enabled.
♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the
rebase/retry checkbox.
🔕 **Ignore**: Close this PR and you won't be reminded about this update
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---
- [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check
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---
This PR was generated by [Mend Renovate](https://mend.io/renovate/).
View the [repository job
log](https://developer.mend.io/github/oxc-project/oxc).
<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0NC4zNS40IiwidXBkYXRlZEluVmVyIjoiNDQuMzUuNCIsInRhcmdldEJyYW5jaCI6Im1haW4iLCJsYWJlbHMiOltdfQ==-->
---------
Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Cameron <cameron.clark@hey.com>
I started reviewing `minimize_conditional_expression` and looks like
there is alot of wasted effort there, esp, when we are re-creating
`ConditionalExpression` recursively by calling `minimize_conditional`,
for now i decided to only optimize `!==` and `!`, but folding of
`SequenceExpression` and creation of all new
`Expression::new_conditional_expression` could be removed as we should
just mutate current expression
`substitute_unary_plus` removes a `+` when the enclosing binary operator
will do the `ToNumber` conversion anyway. The existing doc comment
reasons carefully about `ToNumber` vs `ToNumeric`, but not about *when*
each runs.
`+a` converts `a` while evaluating `+a`, before the right operand is
evaluated at all. `a - n` converts it in
`ApplyStringOrNumericBinaryOperator`, after `n` has been evaluated.
Dropping the `+` therefore moves the conversion across `n`, and a right
operand with a side effect can change what the conversion sees:
```js
var xs = [];
console.log((+xs) - (xs.push(1), 0)); // 0, converted while `xs` was still empty
// oxc emitted:
console.log(xs - (xs.push(1), 0)); // 1, converted after `xs` grew
```
This PR requires the right operand to be free of side effects before
dropping a `+` in the left position. It cannot observe the conversion
either: under the "Coercion Methods Are Pure" assumption the conversion
runs no user code, so there is nothing to observe.
The right position (`n - +a`) is left as is: `n` is evaluated first
either way, and its `ToNumeric` is a no-op because the existing guard
already established that `n` is a number, so nothing runs between
evaluating `a` and converting it.
`cargo minsize` moves the typescript.js gzip figure down by 10 bytes;
every minified size is identical.
The reproduction was found by the minifier fuzzer (#25594) at seed
12397.
### Differential testing
Every case below was run through oxc and then executed in Node against
the unminified source, comparing the result, the mutated state, and the
error constructor *and message*.
| shape | cases | value worlds | runs |
| --- | ---: | ---: | ---: |
| operator × 37 hand-written right operands | 814 | 41 | 33,374 |
| right operand reading a closure variable the conversion may write |
374 | 41 | 15,334 |
| argument shape (`+a.v`, `+f()`, `+(seq(), a)`, `+(+a)`, getter) ×
nesting | 3,168 | 41 | 129,888 |
| random expressions, 3 seeds, depth 2-3 | 7,500 | 41 | 307,500 |
The worlds cover `[]`, `{ valueOf: () => 10n }`, `Symbol()`,
`Object.create(null)`, objects with getters, `Proxy`, and the numeric
edge cases.
No difference survives, other than one that predates this pass and is
discussed in the doc comment: for a `BigInt` argument both forms throw a
`TypeError`, but `+a` says "Cannot convert a BigInt value to a number"
while `a - 1` says "Cannot mix BigInt and other types". The error kind
never changes.
---
Written with AI assistance (Claude Code). Reviewed by me, and the
before/after behaviour was checked against Node.js.
---------
Signed-off-by: Kotaro Chikuba <miz404@gmail.com>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
add `boolean_context` to `minimize_not` so negation folding can happen
in-place when possible, reducing extra AST rebuilds and allocations and
`!0` / `!1` can now collapse directly to `1` / `0` in boolean context
Follow-on after #25585.
Pure style change. I hate the way LLMs put line breaks in weird places like after "the" - it makes comments hard to read. And what's with all the colons and semicolons?
No substantive changes, just reformatting comments and docs to avoid this unreadable formatting.
Cameron