Oxc v0.135 Lands the React Compiler Rust Port and a `#[non_exhaustive]` AST Break

Oxc 0.135.0 and oxlint 1.69.0 shipped on June 8, 2026. The headline is the React Compiler Rust port landing inside the oxc monorepo. The subhead is a breaking AST change that every Rust downstream needs to handle.

React Compiler, in Rust

The most consequential change in 0.135 is PR #22942, "react_compiler: Integrate the Rust port of the React Compiler". Meta has been writing a from-scratch Rust port of the React Compiler, and 0.135 is the version where it ships as a first-class crate inside the oxc workspace. The compiler analyzes React function components and hooks, then emits memoized output that skips re-renders when props and state are referentially stable.

For Rust-based JS/JSX/TS toolchains, this is the missing piece. The previous implementation lived in the React repo as TypeScript, which meant any Rust tool that wanted React Compiler output had to shell out to Node or bundle a JS runtime. With the Rust port inside oxc, Rolldown, Vinext, and future bundlers can integrate the compiler directly, which is the path the VoidZero tooling stack has been building toward since Vite+ alpha launched.

For application developers, the visible change is incremental: smaller minified output and faster builds as downstream bundlers adopt the new crate. The architectural move is what matters for the ecosystem.

The #[non_exhaustive] breaking change

0.135 also marks every Oxc AST node as #[non_exhaustive] (PR #23046). This is a real breaking change for Rust downstreams that pattern-match exhaustively on AST variants: Rolldown, oxc-traverse, oxc-transform, and any custom transformer built on top of oxc_parser will need a patch release with an explicit wildcard arm or _ => branch.

In practice the patch is mechanical. The change is upstream's first time touching AST public surface since the project started treating the AST as a stable contract, and it signals a wider hardening push. If you maintain a Rust crate that depends on oxc, expect a small PR to land soon.

A second, smaller addition: two new AstBuilder methods, template_element_escape_raw and template_element_escape_raw_with_lone_surrogates (PR #23047), for codegen paths that need to handle unpaired surrogates in template literals. Existing builder users do not break, but custom builders should pick up the new methods.

Parser, codegen, and oxlint

The 0.135 parser gains several strictness checks that previously slipped through. Reserved type-declaration names are now reported, as are import-type aliases to non-external references, abstract private class fields, and duplicate switch default clauses. The codegen side adds a long list of whitespace fixes for minified output: tighter conditional-type and constructor-type spacing, dropped redundant spaces after else and export default, and proper spacing around postfix ++ and -- operators.

Oxlint 1.69 ships schemas for 30+ ESLint rules, including jest/vitest/max-expects, jest/vitest/expect-expect, jest/vitest/consistent-test-it, import-max-dependencies, prefer-default-export, sort-vars, radix, prefer-const, no-warning-comments, no-unused-vars, no-shadow, no-restricted-exports, no-param-reassign, no-magic-numbers, no-inner-declarations, no-constant-condition, no-empty-function, id-match, capitalized-comments, id-length, complexity, and class-methods-use-this. The Vue analyzer picks up next-tick-style, require-direct-export, no-reserved-props, and require-prop-types. oxfmt 0.54 rounds out the release with formatter-side fixes that were not breaking.

The release is the natural follow-up to the 0.134 drop covered here, and tracks the project's accelerated cadence: a 0.126 release in April added Turbopack magic comments and an allocator break, a 0.134 in June added Vue and TypeScript rules, and 0.135 lands the React Compiler Rust port. Rolldown, which uses Oxc, picked up lazyBarrel as the default in 1.1.0; the next Rolldown minor is the place to expect the React Compiler integration to surface in production builds.