…9815)

## Summary

In Full Bundle Mode, assets emitted **while generating an HMR patch or compiling a lazy entry** (e.g. an image newly imported by the changed/lazy module) never reached the dev consumer — those paths skip the generate stage, so they never fire `onOutput`, the only asset-delivery channel. The browser then 404s the asset until a full reload.

This adds an `onAdditionalAssets` dev callback that delivers those assets **before** the patch/lazy code reaches the client, so a consumer that serves built files (Vite) can serve them in time.

Fixes vitejs/vite#22596 and its HMR analog. Also addresses #9812 and #9817 in the Vite / bundled-dev path (there the asset URLs are resolved eagerly at `load`/`transform`, and this PR delivers the bytes). Purely additive — no breaking changes.

## Changes

- **New `onAdditionalAssets` callback** through every layer (`rolldown_dev` → napi → TS). Fires before the patch/lazy code reaches the client; the shared `emitted_files` gate keeps each asset delivered exactly once.
- Carries a `BundleOutput` at the Rust boundary so `add_additional_files` warnings get the same treatment as `onOutput`; the napi layer delivers `BindingOutputs` directly (no error path — the bytes are already emitted).
- **test-dev-server** reference consumer: ports the bundled-dev branch of Vite's `vite:asset` plugin (eager URL resolution at `load`; no `__ROLLDOWN_ASSET__` placeholder / `renderChunk`) and registers `onAdditionalAssets` into `memoryFiles`.
- Regression tests: an HMR edit that adds an asset import, and a lazily-compiled module that pulls in an asset (both assert `naturalWidth > 0` on first patch/load, no 404).
- Docs: `internal-docs/dev-engine/implementation.md` §17 (asset emit → deliver dataflow).

## Verifications

- `cargo check` + `clippy` clean; `tsc` clean for `packages/rolldown` and `packages/test-dev-server`.
- New test-dev-server asset specs pass.
- Vite: `bundledDev` registers `onAdditionalAssets`; the `hmr-full-bundle-mode` playground suite is **13/13 green** — the three #22596 scenarios (lazy, HMR patch, HMR full-reload) each serve `image/png` (`naturalWidth=128`) on the first request.

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…9815)

## Summary

In Full Bundle Mode, assets emitted **while generating an HMR patch or compiling a lazy entry** (e.g. an image newly imported by the changed/lazy module) never reached the dev consumer — those paths skip the generate stage, so they never fire `onOutput`, the only asset-delivery channel. The browser then 404s the asset until a full reload.

This adds an `onAdditionalAssets` dev callback that delivers those assets **before** the patch/lazy code reaches the client, so a consumer that serves built files (Vite) can serve them in time.

Fixes vitejs/vite#22596 and its HMR analog. Also addresses #9812 and #9817 in the Vite / bundled-dev path (there the asset URLs are resolved eagerly at `load`/`transform`, and this PR delivers the bytes). Purely additive — no breaking changes.

## Changes

- **New `onAdditionalAssets` callback** through every layer (`rolldown_dev` → napi → TS). Fires before the patch/lazy code reaches the client; the shared `emitted_files` gate keeps each asset delivered exactly once.
- Carries a `BundleOutput` at the Rust boundary so `add_additional_files` warnings get the same treatment as `onOutput`; the napi layer delivers `BindingOutputs` directly (no error path — the bytes are already emitted).
- **test-dev-server** reference consumer: ports the bundled-dev branch of Vite's `vite:asset` plugin (eager URL resolution at `load`; no `__ROLLDOWN_ASSET__` placeholder / `renderChunk`) and registers `onAdditionalAssets` into `memoryFiles`.
- Regression tests: an HMR edit that adds an asset import, and a lazily-compiled module that pulls in an asset (both assert `naturalWidth > 0` on first patch/load, no 404).
- Docs: `internal-docs/dev-engine/implementation.md` §17 (asset emit → deliver dataflow).

## Verifications

- `cargo check` + `clippy` clean; `tsc` clean for `packages/rolldown` and `packages/test-dev-server`.
- New test-dev-server asset specs pass.
- Vite: `bundledDev` registers `onAdditionalAssets`; the `hmr-full-bundle-mode` playground suite is **13/13 green** — the three #22596 scenarios (lazy, HMR patch, HMR full-reload) each serve `image/png` (`naturalWidth=128`) on the first request.

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## [1.1.3] - 2026-06-24

### 🐛 Bug Fixes

- `defer_drop` crashes the browser main thread (#9942) by @shulaoda
- camel-case: correct camel case for nested values (#9933) by @kb019
- cli: display --help options in camelCase (#9941) by @IWANABETHATGUY
- preserve used re-exports under preserveModules (#9122) (#9934) by @IWANABETHATGUY
- watch: make close reentrant in event callbacks (#9904) by @hyf0
- git for windows treats symlink files as regular files (#9915) by @AliceLanniste
- dev: cancel pending full reload on build error (#9903) by @h-a-n-a
- chunking: pass plugin meta to codeSplitting groups name function (#9267) by @Kyujenius
- dev: serve assets emitted during HMR/lazy compile (vite#22596) (#9815) by @h-a-n-a
- release: dry-run step no longer publishes binding packages (#9866) by @Boshen

### 🚜 Refactor

- rolldown_common: model ModuleId as a classified Path/Virtual/Bare enum (#9927) by @Boshen
- remove unused LegacyModuleIdx (#9872) by @shulaoda
- remove unused StmtInfos::get_namespace_stmt_info (#9870) by @shulaoda
- remove unused Module::as_external_mut (#9871) by @shulaoda
- remove unused EcmaAst::is_body_empty (#9869) by @shulaoda
- drop dead is_css_module handling in resolve_dependencies (#9867) by @shulaoda
- drop redundant with_commonjs on cjs source type (#9868) by @shulaoda

### 📚 Documentation

- clarify on drafting PRs (#9952) by @h-a-n-a
- update contribution guidelines (#9944) by @fubhy
- note Rust crates don't follow semver in AGENTS.md (#9905) by @IWANABETHATGUY
- add feedback form (#9159) by @TheAlexLichter

### ⚡ Performance

- utils: avoid allocation in default_sanitize_file_name for clean names (#9928) by @Boshen
- binding: box once-per-build futures before spawn_future (#9864) by @Boshen
- utils: avoid wasted allocation in legitimize_identifier_name (#9926) by @Boshen
- rolldown: fuse the canonical-name dedup and insert in the renamer (#9900) by @Boshen
- rolldown: probe the name map once in ConflictResolver::resolve (#9899) by @Boshen
- cut two heap allocations from wrapped ESM init finalize (#9901) by @Boshen
- rolldown_plugin_vite_reporter: hoist invariant out_dir prefix out of reporter loop (#9873) by @shulaoda
- drop throwaway Vec in wrapped esm init stmt (#9878) by @shulaoda
- borrow owner_filename in build-import-analysis AddDeps (#9874) by @shulaoda

### 🧪 Testing

- cover preserveModules named export via namespace re-export (#6010) (#9937) by @IWANABETHATGUY

### ⚙️ Miscellaneous Tasks

- deps: update napi to v3.9.4 (#9954) by @shulaoda
- reduce noise from CODEOWNERS for trival changes (#9953) by @h-a-n-a
- deps: update mimalloc-safe to 0.1.64 (#9950) by @shulaoda
- deps: update rollup submodule for tests to v4.62.2 (#9931) by @rolldown-guard[bot]
- deps: test mimalloc-safe upstream-mimalloc switch in CI (#9930) by @shulaoda
- rolldown_plugin_vite_build_import_analysis: remove unused v2 code path (#9917) by @shulaoda
- rolldown_plugin_vite_manifest: remove unused is_enable_v2 code path (#9916) by @shulaoda
- rolldown_plugin_vite_asset_import_meta_url: remove unexposed native vite plugin (#9896) by @shulaoda
- rolldown_plugin_vite_asset: remove unexposed native vite plugin (#9895) by @shulaoda
- rolldown_plugin_vite_css_post: remove unexposed native vite plugin (#9894) by @shulaoda
- rolldown_plugin_vite_css: remove unexposed native vite plugin (#9893) by @shulaoda
- rolldown_plugin_vite_html_inline_proxy: remove unexposed native vite plugin (#9892) by @shulaoda
- rolldown_plugin_vite_html: remove unexposed native vite plugin (#9891) by @shulaoda
- deps: update github actions (#9909) by @renovate[bot]
- deps: update rust crate oxc_sourcemap to v8.0.2 (#9910) by @renovate[bot]
- deps: update npm packages (#9912) by @renovate[bot]
- deps: update github actions to v7 (#9913) by @renovate[bot]
- deps: update rolldown-plugin-dts to ^0.26.0 (#9897) by @renovate[bot]
- remove rolldown_filter_analyzer crate (#9865) by @Boshen

### ❤️ New Contributors

* @fubhy made their first contribution in [#9944](#9944)

Co-authored-by: shulaoda <165626830+shulaoda@users.noreply.github.com>

### Description

Rewrites `internal-docs/lazy-compilation/{design,implementation}.md` to match the current implementation. The docs dated back to the initial POC (split out in #9826) and had drifted from the code in several load-bearing places. Every claim was re-verified against current `main` (file/line spot-checks, cross-checked with the playground specs).

#### Corrections to stale / wrong content

- **Proxy templates**: both inline code blocks are now the real `proxy-module-template{,-fetched}.js` verbatim. The stub evicts its runtime cache entry and ends with `return await loadExports($STABLE_PROXY_MODULE_ID)['rolldown:exports']` — the two-level promise chain from #9981 that makes init errors catchable at the consumer's `await import()`. The fetched template returns `loadExports($STABLE_MODULE_ID)` instead of the import namespace (export-name preservation in shared chunks, #9132).
- **Module IDs**: design.md's TL;DR claimed absolute paths are used "consistently throughout the runtime" — runtime lookups actually use stable (cwd-relative) ids; absolute paths survive only in the `/@vite/lazy?id=` param and the fetched template's `import($MODULE_ID)`. Also documents the four template placeholders and their JSON-quoted rendering (#9102).
- **Error handling**: replaced "`Err` or panic is fine for POC" with the actual contract — unknown ids are rejected as a cache-key-only security gate (#9969), napi surfaces `Failed to compile lazy entry:` → HTTP 500, and init errors are catchable on both cold and warm paths (#9975/#9981).
- **Dedup**: the race-condition section's "potential future enhancement" runtime guard is long implemented — lazy chunks render `createEsm/CjsInitializer(stableId, factory, 1)` with a dedup flag (HMR patches deliberately omit it so updates re-execute). Rewrote the section around the two-layer dedup: per-client `executed_modules` pruning + the runtime flag.
- **Rebuild id normalization**: the old note said the `ModuleChanged` rebuild "should resolve or normalize" the proxy id to a real module id — the raw proxy id is deliberately correct (it is the incremental-cache invalidation key for the proxy whose content changed; normalizing would leave the stale stub cached). Note removed and the actual mechanism documented.
- Misc: `lazyMagic` helper (never existed), `__export` → `__exportAll`, `snippet` → `ast_factory` in the Lessons Learned snippets, `registerModule(stableId, { exports })` shape.

#### New coverage

- **Enabling / wiring**: `experimental.devMode.lazy: true`, inner-plugin registration, the shared `LazyCompilationContext` handed to the `DevEngine`
- **Lazy chunk rendering**: initializer wrappers + `__rolldown_module_id__` param, the nested-lazy `import()` → `/@vite/lazy` rewrite, entry init call, `lazy_compile_{n}.js` naming
- **Emitted assets**: delivered via `onAdditionalAssets` before the code returns (#9815)
- **Build output refresh**: `update_watch_paths()` runs first (what makes post-fetch edits watchable at all), silent output swap for connected clients, failure paths (#9903)
- **Editing a fetched lazy module**: per-client HMR outcomes; a non-accepting proxy escalates to FullReload → HmrRebuild with a deferred reload
- **Client sessions**: implicit creation on `hmr:module-registered`, removal on ws disconnect, the `"rolldown-tests"` escape hatch; clientId prunes the patch — nothing is "routed"
- **Known limitations**: link-stage-synthesized exports (JSON/text/base64/dataurl register `{}` inside lazy chunks until rebuild + refresh), CSS error deferral, assets require load-hook plugins, sourcemaps (inline-only for lazy chunks — the map asset is discarded on the lazy path, unlike `HmrPatch`)
- **Test coverage table**: the 7 playground specs + `dev-lazy-compile.test.ts` and what each pins

Docs only — no runtime change.

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