@oxc-project/types

Every stable release, newest first. Notes are quoted as the maintainers published them.

1. 0.154.0

   13 October 2026
   ast: Refactor comment attachment storage

   Breaking changes

   • breaking

     ast: Refactor comment attachment storage

   • breaking

     ast: Add comment attachment storage

   • breaking

     parser: Assign node IDs during parsing

   Features

   • minifier: Add folding of delete expression

   Bug Fixes

   • codegen, packages/codegen: Remove extraneous space before RestElement in ArrayPattern

   • packages/codegen: Support printing V8IntrinsicExpressions

   • minifier: Preserve parameter writes through mapped arguments

   • semantic: Stop arguments resolution at ordinary functions

   • transformer_plugins: Preserve optional chains through non-null assertions

   • crates/oxc_semantic: Decline to evaluate unary ops on strings in enum initializers

   • parser: Apply no-side-effects annotations after export

   • minifier: Preserve delete semantic when folding non-finite numbers

   • minifier: Eliminate unused IIFE calls with constant arguments

   • transformer: Avoid synthetic private fields for static blocks

   • semantic: Mark delete of optional members as MemberWriteTarget

   • codegen: Avoid extra indent before empty do-while bodies

   • codegen: Fix printing negative BigIntLiteral after -

   • packages/codegen: Fix printing negative BigIntLiteral after -

   • packages/codegen: Fix debug assert fail printing TSJSDocNonNullableType

   • semantic: Visit TSMethodSignature computed method keys in enclosing scope

   Performance

   • packages/codegen: Remove all printSpaceBeforeIdentifier calls

   • packages/codegen: Skip redundant printSpaceBeforeIdentifier call

   • packages/codegen: Remove branches from loops printing arrays

   • packages/codegen: Remove branch printing RestElement in ArrayPattern

   • packages/codegen: Reduce branches in printArguments

   • packages/codegen: Remove unnecessary printSpaceBeforeIdentifier calls

2. 0.153.0

   5 October 2026
   minifier: Fold undefined argument in non delegating yield

   Features

   • minifier: Fold undefined argument in non delegating yield

   • ast: Tie debug_name return lifetime to the underlying AST node

   • minifier: Merge import statements against the same module

   • minifier: Merge import and export statements against the same module

   • minifier: Minimize bitwise binary expressions

   • minifier: Merge statements after terminating if block branches

   • minifier: Merge adjucent if stmt with the same content

   Bug Fixes

   • parser: Report abstract private field error on modifier

   • parser: Include generator marker in overload diagnostic span

   • parser: Reject TypeScript class modifiers in JavaScript

   • minifier: Correct indopedency when processing nested sequences

   • parser: Remove type-dependent tuple rest diagnostics

   • parser: Validate TypeScript type member separators

   • parser: Reject module syntax in script

   • parser: Report TS1243 for abstract async methods

   • parser: Report TS1242 for interfaces with abstract modifier

   • parser: Avoid duplicate index signature modifier diagnostic

   • regex: Decode escaped capturing group names

   • minifier: Fold conditional expressions with long sequences

   • isolated-declarations: Allow adding undefined to keyof parameter types

   • isolated-declarations: Support readonly parameter types

   • transformer/explicit-resource-management: Transform classic for loop using declarations

   • minifier: Preserve sibling declarations in arguments copy rewrite

   • transformer/explicit-resource-management: Lower using in catch and finally

   Performance

   • minifier: Small performance improvement when merging imports

   • codegen: Pre-allocate sourcemap builder vectors

   • minifier: Update expressions in place in merge_import_export

3. 0.152.0

   28 September 2026
   str: Add JSStr, JSChar and JSStrBuilder types

   Features

   • str: Add JSStr, JSChar and JSStrBuilder types

   • regular_expression: Support buffer boundary assertions

   • transform-react: Add reportDiagnostics option to expose recoverable React Compiler diagnostics

   • napi: Add threadless WASI builds

   Bug Fixes

   • minifier: Preserve iife with directives

   • str: Correct clippy reason

   • formatter/jsdoc: More alignment with original plugin

   • parser: Handle HTML comment values

   • parser: Reject module export names containing a lone surrogate

   • codegen: Remove redundant dollar escapes in minified templates

   Performance

   • minifier: Fold logical expressions in place

   • minifier: Avoid creation of empty block when folding try finally

   • minifier: Update boolean context expressions in place

   • minifier: Take return argument directly when converting arrow fn

   • minifier: Reduce allocations when minimizing assignments

   • minifier: Use ident hashes for catch var and arguments

   • minifier: Use ident hashes in label comparison

4. 0.151.0

   21 September 2026
   coverage: Support new TypeScript fixture layout

   Features

   • coverage: Support new TypeScript fixture layout

   Bug Fixes

   • minifier: Add missing negation for boolean literal

   • transformer: Skip enum reverse mappings for syntactic string initializers

   • parser: Preserve reparsed await tokens

   • transformer: Skip recovered using loop patterns

   • parser: Recover await using object binding patterns

   • parser: Reject invalid modifiers on import aliases

   Performance

   • minifier: Preallocate stmts vec size to avoid excesive reallocs

   • semantic: Reuse identifier hashes in enum member lookups

   • minifier: Reduce allocations when processing if statements

5. 0.150.0

   14 September 2026
   ecma: Define math constants as known globals and resolve their types

   Features

   • ecma: Define math constants as known globals and resolve their types

   • codegen: Add ascii_only option

   • minifier: Negate binary comparison for typeof x < 'u'

   Bug Fixes

   • parser: Reject accessor modifiers on methods

   • parser: Reject readonly modifier on constructors

   • parser: Handle escaped let in for loops

   • parser: Recognize annotated empty arrows in conditionals

   • parser: Classify Unicode line breaks in block comments

   • transformer: Preserve receivers in private optional chains

   • parser: Reject escaped import-phase keywords

   • parser: Recognize contextual binding names in type lookaheads

   • parser: Require arrow separator in TypeScript function types

   • parser: Disambiguate await using in for initializers

   • parser: Allow parenthesized JSX comma expressions with preserve_parens=false

   • parser: Reject return types on constructor overloads

   • parser: Validate await context for await using declarations

   • parser: Disallow in expressions in using for-loop initializers

   • parser: Allow escaped type names in import and export specifiers

   • parser: Reject async modifiers on class fields

   • parser: Require comma after TypeScript this parameter

   • codegen: Preserve instantiation expression precedence

   • parser: Allow in expressions in class static blocks

   • packages/codegen: Preserve private-in right operand precedence

   • packages/codegen: Preserve in restriction through yield arguments

   • parser: Validate TS named tuple rest elements

   • codegen: Preserve in restriction through yield arguments

   • codegen: Preserve private-in right operand precedence

   • parser: Allow escaped type default import bindings

6. 0.149.0

   7 September 2026
   parser: Rename panicked to fatal_error in ParserReturn

   Breaking changes

   • breaking

     parser: Rename panicked to fatal_error in ParserReturn

   • breaking

     parser: Reduce MAX_LEN to 256 bytes below u32::MAX

   Features

   • allocator: Construct ArenaHashSet with any Default hasher

   • minifier: Process of return/throw in non last position and fix async * inlining

   • parser: Distinguish unapplied no-side-effects comments

   • ast: Add GetNodeId trait

   Bug Fixes

   • codegen: Order accessibility before abstract on accessors

   • transformer/class-properties: Keep private methods in class-expression scope

   • parser: Require a string source after export ... from

   • codegen: Print matching quoted import names as identifiers

   • codegen: Preserve private-in left operand precedence

   • parser: Correctly round large nondecimal literals

   • transformer: Gate async-only rewrites by owning transform

   • transformer: Limit arguments capture to lowered async functions

   • transformer: Gate this capture by owning async transform

   • minifier: Mangle class private members in Node API

   • semantic: Detect duplicate private class elements

   • semantic: Reject await and yield in rest parameter defaults

   • semantic: Reject jumps across arrow functions

   • parser: Do not omit < token opening type argument list

   • ast_visit: Add the trimmed prefix length to translation table offsets

   • parser: Do not re-lex template substitution tail after fatal error

   • parser: Fix debug assert failure when lexer error with tokens enabled

   • allocator: Gate Allocator::data_end_ptr behind fixed_size feature

   • ecmascript: Avoid charAt panic on 32-bit

   • runtime: Remove stale regenerator exports

   Performance

7. 0.148.0

   1 September 2026
   allocator: Make Allocator::cursor_ptr and data_end_ptr private

   Breaking changes

   • breaking

     allocator: Make Allocator::cursor_ptr and data_end_ptr private

   Features

   • minifier: Drop cases whose condition is statically false

   • minifier: Invert !0 and !1 in place for boolean context to 1 and 0

   • minifier: Expand fold leading assignments into the var decl

   • minifier: Expand de morgan's optimization to allow move of !

   • parser: Attach all comments to nodes

   Bug Fixes

   • semantic: Skip body bindings in type parameters and this param

   • semantic: Validate chained continue labels

   • ecmascript: Math.round only exact half ties

   • minifier: Coerce omitted indexOf search argument

   • ecmascript: Trim trailing whitespace in string to number

   • transformer/object-rest: Lower multiple declarators correctly

   • parser: Avoid panic on escaped string export names

   • linter: Clamp invalid JS plugin locations

   • semantic: Skip function body bindings in parameters

   • transform-react: Match Babel diagnostic reporting

   • parser: Correctly classify unapplied pure annotations

   • linter/plugins: Alter method for obtaining mutable Program when sending AST to JS plugins

   • regular_expression: Allow oversized decimal escape for Annex B

   • regular_expression: Reject oversized backreferences

   Performance

   • diagnostics: Use fixed ANSI styles

   • packages/codegen: Flatten output in chunks

   • packages/codegen: Faster string flattening

   • packages/codegen: Ensure indent strings are flattened

   • packages/codegen: Store mapping positions in an Int32Array

8. 0.147.0

   24 August 2026
   minifier: Fold switch stmt whose parent is not block stmt

   Features

   • minifier: Fold switch stmt whose parent is not block stmt

   Bug Fixes

   • codegen: Require sourcemap for example

   • estree: Include decorators in FormalParameterRest spans

   • minifier: Avoid merging if to for in sloppy mode when containing function declaration

   • rust: Address nightly deprecations

   • codegen: Only add mapping names for PrivateIdentifiers which have changed

   • parser: Track irregular line terminators in trivia

   • minifier: Avoid merging if to for when the body contains a function declaration

   • codegen: Print # before private identifier in TS signature key

   • minifier: Keep unary + when the other operand has side effects

   Performance

   • packages/codegen: Remove node param from write and markMap functions in sourcemap builds

   • packages/codegen: Pass start and end to write and mark functions

   • packages/codegen: Replace write calls with writeIdent

   • packages/codegen: Remove last param from writeWithMapNamed

   • packages/codegen: Eagerly initialize mapNames

   • packages/codegen: Split recording mappings into multiple functions

   • packages/codegen: Reduce property lookups

   • packages/codegen: Combine condition checks

   • packages/codegen: Add functions for writing/marking unnamed mappings

   • codegen: Avoid allocations for single comment anchors

   • minifier: Do not rebuild expression when substituting void to null

   • packages/codegen: Merge mark and write calls in printImportAttributes

   • packages/codegen: Remove node param from printString and printNonNegativeFloat

   • packages/codegen: printNonNegativeFloat write mapping directly

   • minifier: Avoid creation of unnecessary conditional expressions

   • packages/codegen: Remove lastWasPostfixClose

9. 0.146.0

   19 August 2026
   minifier: Improve negation of expressions in boolean context

   Features

   • minifier: Improve negation of expressions in boolean context

   Bug Fixes

   • codegen: Narrow printSync input type

   • isolated-declarations: Preserve unresolved parameter types

   • codegen: Remove deprecated test APIs

   • codegen: Align enum template sourcemaps

   Performance

   • packages/codegen: Check sourceText only once

   • minifier: Unwrap all unary exprs without creating dummy expressions

   • packages/codegen: Remove loop from growMappingBuffer

   • packages/codegen: Remove redundant branch

   • packages/sourcemap: Make location passed to recordSourceMapping always a number

   • packages/codegen: Take named-mapping only code off hot path in recordSourceMapping

   • packages/codegen: Remove redundant setting of last in printImportAttributes and printIf

   • packages/codegen: Combine 2 writes in printJSXElement

   • packages/codegen: Remove redundant mapping from printParams

10. 0.145.0

    18 August 2026
    packages/codegen: printSync return an object

    Breaking changes

    • breaking

      packages/codegen: printSync return an object

    Features

    • packages/codegen: Alter capitalization of sourceFilename option

    • packages/codegen: Add full source map support

    • napi/minify: Expose property name mangling options

    • minifier: Add property name mangling

    • mangler: Deduplicate private accessor names

    • napi: Add Relay transform plugin

    • codegen: Add oxc-codegen package

    Bug Fixes

    • codegen: Validate sourcemap options

    • react_compiler: Skip node_modules by default

    • minifier: Drop side-effect-free additions

    • napi/minify: Accept RegExp for property filters

    • codegen: Reject invalid indent options

    • isolated-declarations: Preserve undefined for defaulted any

    • codegen: Preserve property key annotations

    • minifier: Model uninitialized module vars as undefined

    • ecmascript: Fold ** with Number::exponentiate, not IEEE pow

    • isolated-declarations: Handle ambient expando properties

    • react-compiler: Standardize diagnostics

    • parser: Reject initialized lexical declarations in for-in

    • parser: Forbid type parameters on quoted constructors

    • react-compiler: Use Babel v1 validation defaults

    • napi: Disable reuseWorker in browser bindings

    • react_compiler: Preserve JSX import source pragmas

    • semantic: Respect shadowed Infinity and NaN in enum evaluation

    • minifier: Keep variable declaration initilized with class when keepNames is enabled

    • minifier: Keep side effects when rotating bitwise operands