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Latest Results

chore(ts/fast-strip): add changeset for UTF-16 fix
fix/type-strip-utf16
1 hour ago
feat(es/react-compiler): expose `reactCompiler.environment.enableFunctionOutlining` (#12030) **Description:** The Babel React Compiler lets consumers configure `environment` options, but SWC's `reactCompiler` config previously exposed none of them — the compiler's `EnvironmentConfig` was always left at its defaults, unreachable from `.swcrc`. This adds a curated `environment` object to the `reactCompiler` config that mirrors Babel's `reactCompiler.environment` shape. It currently exposes a single field, `enableFunctionOutlining`, wired through to `EnvironmentConfig::enable_function_outlining`: ```json { "jsc": { "transform": { "reactCompiler": { "environment": { "enableFunctionOutlining": false } } } } } ``` The object is a deliberate allowlist rather than a passthrough of the full `EnvironmentConfig`: unset fields leave the compiler defaults untouched, so a partial object overrides only what it names, and the public surface stays small and intentional. New fields can be added one at a time as they are wired and tested. `EnvironmentConfig` is re-exported from `swc_ecma_react_compiler` so the config layer can name the type (it was already reachable via the public `PluginOptions.environment`). Tests: - unit test covering `environment.enableFunctionOutlining` deserialization; - fixture `environment-function-outlining-disabled`: with outlining off, a closure that captures a local binding stays inline; - fixture `environment-function-outlining-enabled`: with outlining on (default), a closure that captures nothing is outlined into a top-level helper. **BREAKING CHANGE:** None. `environment` is a new optional field; existing configs are unaffected. **Related issue (if exists):** N/A --------- Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
main
3 hours ago
chore: Add React Compiler environment changeset
imjordanxd:feat/react-compiler-enable-function-outlining
3 hours ago
refactor(es/typescript): track enum evaluation context
refactor/enum-evaluation-context
7 hours ago
fix(es/typescript): evaluate cooked enum templates
fix/enum-template-cooked
7 hours ago
fix(es/minifier): preserve invalid Array lengths
fix/array-constructor-length
8 hours ago
fix(es/minifier): apply ToUint16 in fromCharCode
fix/string-from-char-code-uint16
8 hours ago
fix(es/minifier): avoid inexact number radix folding
fix/number-radix-conversion
8 hours ago

Latest Branches

CodSpeed Performance Gauge
+11%
fix(ts/fast-strip): preserve UTF-16 source positions#12067
2 hours ago
be61cb7
fix/type-strip-utf16
CodSpeed Performance Gauge
+3%
feat(es/react-compiler): expose `reactCompiler.environment.enableFunctionOutlining`#12030
3 hours ago
949116c
imjordanxd:feat/react-compiler-enable-function-outlining
CodSpeed Performance Gauge
-4%
1 day ago
615ead6
refactor/enum-evaluation-context
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