## [1.2.0] - 2026-07-15

### 🚀 Features

- dev: skip shipping factories for newly imported top-level modules (#10223) by @h-a-n-a
- dev: per-client ship map for HMR patch sizing (#10208) by @h-a-n-a
- dev: client-side HMR (#10164) by @h-a-n-a
- dev: send a full-reload update to clients when a tsconfig changes (#10262) by @shulaoda
- treat `import.meta['url']` and `import.meta['ROLLUP_FILE_URL_*']` as side-effect free (#10267) by @sapphi-red
- rewrite `import.meta['url']` (#10251) by @sapphi-red
- add `FILE_NOT_FOUND` error (#10220) by @sapphi-red
- treat `import.meta.ROLLUP_FILE_URL_*` as side-effect free (#10217) by @sapphi-red

### 🐛 Bug Fixes

- sourcemap: preserve unmapped boundaries during composition (#10254) by @hyfdev
- `[format]` in `*FileNames` option for ESM format should be `es` instead of `esm` (#10214) by @sapphi-red
- sourcemap: preserve coarse mappings during composition (#10249) by @hyfdev
- rolldown_plugin_vite_import_glob: support tsconfig paths with `import.meta.glob` (#10167) by @sapphi-red
- dev: clear tsconfig caches for bare full builds (#10276) by @shulaoda
- dev: force a full rebuild when a tsconfig changes (#10261) by @shulaoda
- treat rooted drive-less module ids as absolute in preserveModules naming (#10235) by @IWANABETHATGUY
- watch: rebuild when tsconfig files change (#10258) by @shulaoda
- watch: drop tsconfig-merged transform options on each rebuild (#10257) by @shulaoda
- incorrect `EMPTY_IMPORT_META` warning for `import.meta.ROLLUP_FILE_URL_*` for CJS output (#10221) by @sapphi-red
- deconflict: rename CJS locals shadowing wrapped-ESM namespace objects (#9970) by @IWANABETHATGUY
- rolldown: drop the unused runtime module after entry-level external flattening (#10237) by @IWANABETHATGUY
- rolldown: re-propagate has_dynamic_exports to transitive star importers (#10239) by @IWANABETHATGUY
- tree-shaking: tree-shake destructured dynamic import namespace bindings (#10213) by @logaretm
- s390x: use json-escape-simd 3.1.1 for big-endian JSON escaping fix (#10211) by @satyamg1620

### 🚜 Refactor

- dev: move full-reload to client side (#10207) by @h-a-n-a
- readability follow-ups to the ReplaceWith migration (#10286) by @IWANABETHATGUY
- replace take_in-then-write-back with ReplaceWith and by-value moves (#10285) by @Boshen
- share the main resolver's cache with the transformer's tsconfig lookups (#10205) by @shulaoda
- rolldown: extract the ns star-external __reExport emission rule into LinkingMetadata (#10238) by @IWANABETHATGUY
- rolldown: unify link/generate diagnostics into a Diagnostics accumulator (#10234) by @IWANABETHATGUY
- sourcemap_filenames: drop dead sourcemap-filename plumbing (#10189) by @IWANABETHATGUY
- extract external import symbol merging into a method (#10224) by @IWANABETHATGUY
- rolldown: skip CJS namespace merging under strict execution order (#10203) by @hyfdev
- resolve the manual tsconfig per file instead of once at startup (#10200) by @shulaoda
- rolldown: route interop ESM init emission through a shared init-target view (#10202) by @hyfdev
- rolldown: collapse vestigial wrap-kind state and share chunk sort helper (#10201) by @hyfdev

### 📚 Documentation

- show plugin kinds in JSDoc and each hook's description (#10218) by @sapphi-red
- add an explanation about removing imports from external modules without any messages (#10215) by @sapphi-red

### ⚡ Performance

- sourcemap: owned merge in SourceJoiner::join (4005->5 allocs/chunk) (#10250) by @Boshen
- avoid redundant sourcemap string copies in collapse and minify paths (#10093) by @Boshen

### 🧪 Testing

- code-splitting: establish strict-order review baselines (#10287) by @hyfdev
- dev: add hot API test cases (#10181) by @h-a-n-a
- code-splitting: normalize strict execution order variants (#10277) by @hyfdev
- code-splitting: harden strict execution order coverage (#10252) by @hyfdev
- code-splitting: add strict execution order regressions (#10253) by @hyfdev

### ⚙️ Miscellaneous Tasks

- deps: update github actions (#10241) by @renovate[bot]
- deps: update oxc to 0.140.0 (#10274) by @shulaoda
- update Yunfei's GitHub username (#10275) by @hyfdev
- deps: update napi (#10260) by @renovate[bot]
- deps: update test262 submodule for tests (#10266) by @rolldown-guard[bot]
- deps: update dependency vite-plus to v0.2.4 (#10256) by @renovate[bot]
- deps: update napi (#10240) by @renovate[bot]
- deps: update oxc resolver to v11.24.2 (#10245) by @renovate[bot]
- deps: update rust crates (#10244) by @renovate[bot]
- disable Renovate updates for idna_adapter (#10248) by @shulaoda
- deps: update oxc resolver to v11.24.1 (#10232) by @renovate[bot]
- deps: update rust crate oxc_sourcemap to v8.1.1 (#10233) by @renovate[bot]
- deps: update dependency rolldown-plugin-dts to ^0.27.0 (#10206) by @renovate[bot]
- deps: upgrade sugar_path to v3 (#10230) by @hyfdev
- add `dist-*` to `.gitignore` in sourcemap-filenames/hash-final-content fixture (#10216) by @sapphi-red
- deps: update dependency rust to v1.97.0 (#10209) by @renovate[bot]

### ❤️ New Contributors

* @satyamg1620 made their first contribution in [#10211](#10211)

Co-authored-by: shulaoda <[email protected]>

Single-reconciliation merge of 52 new main commits (replaying 194 branch
commits as a rebase would cascade Cargo.lock/Cargo.toml regen across dozens
of steps). All conflicts resolved preserving the drop-tokio ports on top of
main's changes:

- plugin_vite_import_glob: kept the branch's pre-resolved async glob lookup;
  re-applied main's #10167 always-insert `ViteImportGlob(is_sub_imports_pattern)`
  into the branch's relocated resolve in lib.rs so tsconfig-paths glob support
  survives.
- plugin_vite_dynamic_import_vars: branch's block_on-free transform_program +
  main's relative_path_as_js_specifier normalization.
- asset_module / copy_module: dropped both tokio (branch) and the now-unused
  sugar_path (main cleanup).
- rolldown_dev + rolldown_watcher: async_lock::Mutex (branch) + main's HMR
  delivery protocol (stamp_table/pending_payloads/shipped/seq). Ported main's
  new tokio::sync::Mutex fields to async_lock; rebuilt generate_hmr_updates as
  main's protocol body with the branch's async DevCallbackResult callbacks;
  dropped main-removed has_full_reload_update; awaited the tsconfig full-reload
  callback.
- binding_dev_engine + dev-engine.ts: main's client protocol (registerClient /
  notifyPayloadDelivered / removeClient, compileEntry -> BindingLazyChunkOutput)
  wrapped in the branch's lifecycle; dropped invalidate (main deleted it).

Adapted rolldown_binding to the re-pinned napi v3.10.5 (56e32d5c): ObjectFinalize
now takes `self`; AsyncBlockBuilder needs `<V, F>` for the defaulted Dispose;
PromiseRaw::new is safe. Full workspace compiles clean.

KNOWN GAP (not pushed): main bumped oxc 0.139.0 -> 0.140.0 (#10274), so the
`patch/oxc-0.139.0-no-tokio-rt` patch no longer applies and oxc 0.140.0's *_napi
crates re-enable napi/tokio_rt -> tokio reappears in the shipped graph. Needs a
`patch/oxc-0.140.0-no-tokio-rt` branch (0.140.0 + PR #24475) before the
drop-tokio invariant holds.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T34fMrYCf2V13Mg8BKmnda

#24349 made unused-class removal conservatively keep every class whose heritage resolves to a class, lexical, or `var` binding. That preserves class-evaluation errors which the minifier assumptions explicitly allow optimizations to ignore, and it leaves `(class extends Base {});` residue in Rolldown chunks after tree-shaking ([rolldown#10274](rolldown/rolldown#10274)).

The minifier already documents both `No TDZ Violation` and `No side effects from extending a class`, and `oxc_ecmascript` explicitly ignores invalid-superclass errors so removable derived classes are not broadly deoptimized. Treat resolved identifier heritage like other pure reads while retaining the pre-existing literal-arrow exception, including its paren/sequence unwrap. Effects from evaluating the heritage expression, decorators, and effectful class elements remain observable.

The runtime harness already has minifier-only exclusions for unsupported inputs. Six Test262 fixtures covered by these assumptions are skipped only before the minifier variant, with the reason documented beside the list; codegen and transformer still execute, and `runtime.snap` remains unchanged.

## Example

Input:

```js
export var Base = class {};
export var Keep = class extends Base {};
var REMOVE = class extends Base {};
```

Before:

```js
var Base = class {}, Keep = class extends Base {};
(class extends Base {});
export { Base, Keep };
```

After:

```js
var Base = class {}, Keep = class extends Base {};
export { Base, Keep };
```

Verified with `cargo test -p oxc_minifier`, `cargo coverage runtime`, Clippy with warnings denied for `oxc_minifier` and `oxc_coverage`, `just minsize`, `just allocs`, formatting, and `just ready`. Minsize and `runtime.snap` are unchanged; the allocation snapshot records fewer allocations for `kitchen-sink.tsx`.

Implemented with AI assistance (Claude Code and OpenAI Codex). The contributor remains responsible for reviewing, understanding, and submitting the changes under the repository AI usage policy.