Adds e2e tests for the design principles in `meta/design/dev-engine.md` (all except panics), in the `hmr-full-bundle-mode` playground. One folder + one spec per scenario, same layout as `lazy-compilation`. Each check in the specs is tagged with the principle it proves (`Design Principle 1/2/3`).

This fully tests the fixes raised in #9652 and #9686

## New tests

- **`initial-error.spec.ts`** — the first build fails (syntax error). The page shows the error overlay, refreshing does not retry the build, and fixing the file recovers.
- **`rebuild-error.spec.ts`** — a rebuild fails (`generateBundle` throws, controlled by a flag file). The overlay shows and survives a refresh, refreshing never retries, each new failed build reports its own error, and a file change recovers. Also checks that opening the page on fresh output never triggers a build.
- **`hmr-error.spec.ts`** — an HMR update fails (syntax error). Refreshing the page triggers a full rebuild — the one case where page access starts a build. A second refresh does nothing, and fixing the file recovers.

What each test checks is observable from the outside: `/_dev/status` (`buildSeq` proves whether a build ran), the error overlay, and page content.

## Other changes

- Rewrote the comments in `tests/playground/` in simple english, keeping the useful references (design doc, PR numbers, file paths).
- Synced two stale notes in `dev-engine.md` (the refresh-after-HMR-error escape hatch is now wired up and covered by a test).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

## [1.1.2] - 2026-06-18

### 📝 Notable tsconfig behavior changes

These ship via the `oxc_resolver` 11.21.3 bump (#9841) and affect `resolve.tsconfigPaths` (Vite 8 resolves through oxc-resolver):

- **Honor explicit non-TS extensions in `include`** (oxc-project/oxc-resolver#1213). `compilerOptions.paths` now resolve for importers whose extension is explicitly listed in a tsconfig's `include` (e.g. `src/**/*.vue`, `src/**/*.svelte`). Previously oxc-resolver filtered importers by extension before evaluating the `include` globs, so a `.vue`/`.svelte` file listed in `include` never matched its project and its `paths` were skipped. This unblocks the default create-vite Vue + TS layout (a solution-style root plus a referenced `tsconfig.app.json` that declares `paths` and `include: ["src/**/*.ts", "src/**/*.vue"]`). Matches vue-tsc and svelte-check, which register these extensions via TypeScript's `extraFileExtensions`.
- **No fallback to the outermost tsconfig in auto-discovery** (oxc-project/oxc-resolver#1220). Auto-discovery no longer attaches the topmost ancestor `tsconfig.json` to a file that no project actually owns (via `files` / `include` / project references). Previously such a file inherited the outermost ancestor's `paths` / `baseUrl`, leaking aliases into files that project does not own. oxc-resolver now returns no config in that case, matching tsserver / typescript-go, which route such files to an inferred project with no aliases.

### 🚀 Features

- add option named for invalid return type errors for more places (#9846) by @shulaoda
- add option names for invalid return type errors (#9821) by @sapphi-red
- transform: infer decorator strictNullChecks from tsconfig (#9590) by @kylecannon
- expose React Compiler options for rolldown and Vite users (#9801) by @Boshen
- tracing: gate chrome-json trace layer behind `chrome-tracing` feature (#9773) by @hyf0
- dev: align test-dev-server with Vite dev server (#9668) by @h-a-n-a

### 🐛 Bug Fixes

- plugin_timings: point doc link to existing checks reference page (#9837) by @hyf0
- generator: correct contradictory panic message in cjs cross-chunk symbol lookup (#9836) by @hyf0
- esm: preserve with clause on export * from external (#9796) by @hyf0
- Make external_import_binding_merger deterministic (#9755) by @naruaway
- surface invalid `manualCodeSplitting` group `test` regex as an error (#9792) by @shulaoda
- avoid panic on `output.file` without a file name (#9789) by @shulaoda
- avoid O(N^2) rendering of high-volume diagnostics (#9748) (#9749) by @IWANABETHATGUY
- avoid panic on JSON numbers outside f64 range (#9788) by @shulaoda
- deps: bump mimalloc-safe to 0.1.63 to fix worker_threads segfault (#9785) by @shulaoda
- cache ESM evaluation errors (#9784) by @sapphi-red
- wrap node require helper in pure IIFE (#9783) by @kb019
- lazy-barrel: load locally-used imports on a re-exported record (#9757) by @shulaoda
- avoid dangling wrapped-ESM init call across chunks (#9502) (#9717) by @IWANABETHATGUY
- dev: detect same-second rewrites in CI poll watcher (#9736) by @h-a-n-a
- dev: force rebuild after HMR errors (#9686) by @h-a-n-a
- dev: print build errors on browser refresh after a failed build (#9652) by @h-a-n-a

### 🚜 Refactor

- single-source the chunk $N symbol-naming algorithm (#9831) by @Dunqing
- simplify common_dir helper (#9857) by @IWANABETHATGUY
- drop commondir crate in favor of in-house helper (#9849) by @Boshen
- binding: extract helpers from normalize_binding_options (#9842) by @Boshen
- move rolldown_filter_analyzer to tasks and scope oxc cfg feature (#9839) by @Boshen
- options: merge manualCodeSplitting into codeSplitting object form (#9805) by @IWANABETHATGUY
- options: support codeSplitting object form in CodeSplittingMode (#9804) by @IWANABETHATGUY
- diagnostic: reuse ByteLocator for per-source line lookup (#9762) by @IWANABETHATGUY
- remove redundant Arc around tracing spans (#9778) by @camc314
- remove unnecessary `Arc` around sourcemap sender (#9777) by @camc314
- rolldown_plugin_vite_wasm_fallback: remove the plugin (#9775) by @sapphi-red
- binding: remove infer-able `napi(ts_type)` (#9737) by @sapphi-red
- remove preprocessor span dedup (#9734) by @hyf0
- identify AST nodes by NodeId instead of Span/Address (#9609) by @IWANABETHATGUY

### 📚 Documentation

- tsconfig: align auto-discovery docs with oxc-resolver behavior (#9845) by @shulaoda
- relocate meta/design to internal-docs, split design from implementation (#9826) by @h-a-n-a
- meta: add options normalization design doc (#9818) by @IWANABETHATGUY
- document why the napi tracing feature is enabled (#9766) by @Boshen
- dev: move test-dev-server test guidance into the testing docs (#9809) by @h-a-n-a

### ⚡ Performance

- drop unused regex unicode property tables from the binding (#9848) by @Boshen
- drop urlencoding crate in favor of percent-encoding (#9851) by @Boshen
- drop owo-colors supports-colors feature in vite reporter (#9824) by @Boshen
- skip enum member value extraction for non-TypeScript modules (#9840) by @shulaoda
- rolldown: use unstable sort for itertools sorted_by at unique-key sites (#9827) by @Boshen
- cheaper deterministic ordering in external import binding merger (#9810) by @IWANABETHATGUY
- disable idna's ICU backend by pinning idna_adapter to 1.0.0 (-129 KB) (#9811) by @Boshen
- size: use unstable sort where stability is unneeded (#9803) by @Boshen
- remove num-format dependency from vite reporter (#9795) by @Boshen
- reduce js callback error size (#9776) by @Boshen
- rolldown_error: remove Debug supertrait from BuildEvent (#9798) by @Boshen
- reduce plugin hook order code size (#9761) by @Boshen
- deps: disable `infer` default features to reduce binary size (#9765) by @Boshen
- reduce pluginable monomorphization size (#9771) by @Boshen
- avoid rebuilding replace plugin values (#9764) by @Boshen
- defer link-stage-output drop to rayon workers after output is produced (#9733) by @Brooooooklyn
- tree-shaking: hoist already-included guard to call sites in inclusion DFS (#9738) by @Brooooooklyn
- renamer: dedup before allocating the owned name in add_symbol_in_root_scope (#9740) by @Brooooooklyn

### 🧪 Testing

- allocs: track allocation counts for rolldown_sourcemap (#9835) by @hyf0
- bench: add CodSpeed micro-benchmarks for rolldown_sourcemap (#9834) by @hyf0
- add cjs named export mutation test (#9823) by @sapphi-red
- dev: restore shared-page reliability conventions in AGENTS.md (#9786) by @h-a-n-a
- dev: add `AGENTS.md` test guidance for agents (#9763) by @h-a-n-a
- dev: split out initial-build-error into its own playground (#9772) by @h-a-n-a
- dev: align e2e suite with Vite and parallelize playgrounds (#9759) by @h-a-n-a
- remove unnecessary module namespace object JSON serializations in tests (#9725) by @sapphi-red
- use `assert.deepStrictEqual` instead of `assert.deepEqual` by using `assert/strict` instead of `assert` (#9724) by @sapphi-red
- hmr: add test case for #5301 (#5302) by @sapphi-red
- dev: add tests for dev-engine principles (#9720) by @h-a-n-a
- dev: align dev-engine test harness with Vite (#9684) by @h-a-n-a

### ⚙️ Miscellaneous Tasks

- deps: update napi to 3.9.3 (#9862) by @shulaoda
- deps: update oxc to 0.137.0 (#9856) by @Boshen
- re-enable default lld linker on x86_64-unknown-linux-gnu (#9855) by @Boshen
- deps: bump vite-plus to 0.2.1 (#9850) by @Boshen
- skills: translate _config.json when encoding rolldown REPL links (#9847) by @IWANABETHATGUY
- deps: update oxc_resolver and oxc_resolver_napi to 11.21.3 (#9841) by @Boshen
- pin vite-plus (vp) CLI to 0.1.24 in setup-vp (#9830) by @Boshen
- add crate/package-level CODEOWNERS (#9819) by @IWANABETHATGUY
- drop unused derive_more display feature from rolldown_plugin (#9820) by @Boshen
- remove auto-assign PR workflow (#9807) by @IWANABETHATGUY
- deps: update rollup submodule for tests to v4.62.0 (#9780) by @rolldown-guard[bot]
- deps: update esbuild for tests to 0.28.1 (#9779) by @rolldown-guard[bot]
- deps: update test262 submodule for tests (#9781) by @rolldown-guard[bot]
- deps: update oxc to 0.136.0 (#9770) by @Boshen
- add pull request template (#9756) by @sapphi-red
- clarify `rolldown_plugin_vite_*` is compatible for the same minor (#9774) by @sapphi-red
- deps: update github actions (#9745) by @renovate[bot]
- deps: update rust crates (#9747) by @renovate[bot]
- deps: update napi to v3.9.2 (#9744) by @renovate[bot]
- deps: update npm packages (#9746) by @renovate[bot]
- deps: update @napi-rs/cli and emnapi deps (#9741) by @Brooooooklyn
- generator: fix `vp fmt` on Windows (#9727) by @sapphi-red
- ban importing from `assert` and recommend `assert/strict` (#9726) by @sapphi-red

### ❤️ New Contributors

* @naruaway made their first contribution in [#9755](#9755)
* @kb019 made their first contribution in [#9783](#9783)

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

## [1.0.16] - 2026-06-18

### 🚀 Features

- add option named for invalid return type errors for more places
(rolldown#9846) by `@shulaoda`
- add option names for invalid return type errors (rolldown#9821) by
`@sapphi-red`
- transform: infer decorator strictNullChecks from tsconfig (rolldown#9590) by
`@kylecannon`
- expose React Compiler options for rolldown and Vite users (rolldown#9801) by
`@Boshen`
- tracing: gate chrome-json trace layer behind `chrome-tracing` feature
(rolldown#9773) by `@hyf0`
- dev: align test-dev-server with Vite dev server (rolldown#9668) by `@h-a-n-a`

### 🐛 Bug Fixes

- plugin_timings: point doc link to existing checks reference page
(rolldown#9837) by `@hyf0`
- generator: correct contradictory panic message in cjs cross-chunk
symbol lookup (rolldown#9836) by `@hyf0`
- esm: preserve with clause on export * from external (rolldown#9796) by `@hyf0`
- Make external_import_binding_merger deterministic (rolldown#9755) by
`@naruaway`
- surface invalid `manualCodeSplitting` group `test` regex as an error
(rolldown#9792) by `@shulaoda`
- avoid panic on `output.file` without a file name (rolldown#9789) by
`@shulaoda`
- avoid O(N^2) rendering of high-volume diagnostics (rolldown#9748) (rolldown#9749) by
`@IWANABETHATGUY`
- avoid panic on JSON numbers outside f64 range (rolldown#9788) by `@shulaoda`
- deps: bump mimalloc-safe to 0.1.63 to fix worker_threads segfault
(rolldown#9785) by `@shulaoda`
- cache ESM evaluation errors (rolldown#9784) by `@sapphi-red`
- wrap node require helper in pure IIFE (rolldown#9783) by `@kb019`
- lazy-barrel: load locally-used imports on a re-exported record (rolldown#9757)
by `@shulaoda`
- avoid dangling wrapped-ESM init call across chunks (rolldown#9502) (rolldown#9717) by
`@IWANABETHATGUY`
- dev: detect same-second rewrites in CI poll watcher (rolldown#9736) by
`@h-a-n-a`
- dev: force rebuild after HMR errors (rolldown#9686) by `@h-a-n-a`
- dev: print build errors on browser refresh after a failed build
(rolldown#9652) by `@h-a-n-a`

### 🚜 Refactor

- single-source the chunk $N symbol-naming algorithm (rolldown#9831) by
`@Dunqing`
- simplify common_dir helper (rolldown#9857) by `@IWANABETHATGUY`
- drop commondir crate in favor of in-house helper (rolldown#9849) by `@Boshen`
- binding: extract helpers from normalize_binding_options (rolldown#9842) by
`@Boshen`
- move rolldown_filter_analyzer to tasks and scope oxc cfg feature
(rolldown#9839) by `@Boshen`
- options: merge manualCodeSplitting into codeSplitting object form
(rolldown#9805) by `@IWANABETHATGUY`
- options: support codeSplitting object form in CodeSplittingMode
(rolldown#9804) by `@IWANABETHATGUY`
- diagnostic: reuse ByteLocator for per-source line lookup (rolldown#9762) by
`@IWANABETHATGUY`
- remove redundant Arc around tracing spans (rolldown#9778) by `@camc314`
- remove unnecessary `Arc` around sourcemap sender (rolldown#9777) by `@camc314`
- rolldown_plugin_vite_wasm_fallback: remove the plugin (rolldown#9775) by
`@sapphi-red`
- binding: remove infer-able `napi(ts_type)` (rolldown#9737) by `@sapphi-red`
- remove preprocessor span dedup (rolldown#9734) by `@hyf0`
- identify AST nodes by NodeId instead of Span/Address (rolldown#9609) by
`@IWANABETHATGUY`

### 📚 Documentation

- tsconfig: align auto-discovery docs with oxc-resolver behavior (rolldown#9845)
by `@shulaoda`
- relocate meta/design to internal-docs, split design from
implementation (rolldown#9826) by `@h-a-n-a`
- meta: add options normalization design doc (rolldown#9818) by
`@IWANABETHATGUY`
- document why the napi tracing feature is enabled (rolldown#9766) by `@Boshen`
- dev: move test-dev-server test guidance into the testing docs (rolldown#9809)
by `@h-a-n-a`

### ⚡ Performance

- drop unused regex unicode property tables from the binding (rolldown#9848) by
`@Boshen`
- drop urlencoding crate in favor of percent-encoding (rolldown#9851) by
`@Boshen`
- drop owo-colors supports-colors feature in vite reporter (rolldown#9824) by
`@Boshen`
- skip enum member value extraction for non-TypeScript modules (rolldown#9840)
by `@shulaoda`
- rolldown: use unstable sort for itertools sorted_by at unique-key
sites (rolldown#9827) by `@Boshen`
- cheaper deterministic ordering in external import binding merger
(rolldown#9810) by `@IWANABETHATGUY`
- disable idna's ICU backend by pinning idna_adapter to 1.0.0 (-129 KB)
(rolldown#9811) by `@Boshen`
- size: use unstable sort where stability is unneeded (rolldown#9803) by
`@Boshen`
- remove num-format dependency from vite reporter (rolldown#9795) by `@Boshen`
- reduce js callback error size (rolldown#9776) by `@Boshen`
- rolldown_error: remove Debug supertrait from BuildEvent (rolldown#9798) by
`@Boshen`
- reduce plugin hook order code size (rolldown#9761) by `@Boshen`
- deps: disable `infer` default features to reduce binary size (rolldown#9765)
by `@Boshen`
- reduce pluginable monomorphization size (rolldown#9771) by `@Boshen`
- avoid rebuilding replace plugin values (rolldown#9764) by `@Boshen`
- defer link-stage-output drop to rayon workers after output is produced
(rolldown#9733) by `@Brooooooklyn`
- tree-shaking: hoist already-included guard to call sites in inclusion
DFS (rolldown#9738) by `@Brooooooklyn`
- renamer: dedup before allocating the owned name in
add_symbol_in_root_scope (rolldown#9740) by `@Brooooooklyn`

### 🧪 Testing

- allocs: track allocation counts for rolldown_sourcemap (rolldown#9835) by
`@hyf0`
- bench: add CodSpeed micro-benchmarks for rolldown_sourcemap (rolldown#9834) by
`@hyf0`
- add cjs named export mutation test (rolldown#9823) by `@sapphi-red`
- dev: restore shared-page reliability conventions in AGENTS.md (rolldown#9786)
by `@h-a-n-a`
- dev: add `AGENTS.md` test guidance for agents (rolldown#9763) by `@h-a-n-a`
- dev: split out initial-build-error into its own playground (rolldown#9772) by
`@h-a-n-a`
- dev: align e2e suite with Vite and parallelize playgrounds (rolldown#9759) by
`@h-a-n-a`
- remove unnecessary module namespace object JSON serializations in
tests (rolldown#9725) by `@sapphi-red`
- use `assert.deepStrictEqual` instead of `assert.deepEqual` by using
`assert/strict` instead of `assert` (rolldown#9724) by `@sapphi-red`
- hmr: add test case for rolldown#5301 (rolldown#5302) by `@sapphi-red`
- dev: add tests for dev-engine principles (rolldown#9720) by `@h-a-n-a`
- dev: align dev-engine test harness with Vite (rolldown#9684) by `@h-a-n-a`

### ⚙️ Miscellaneous Tasks

- add rollipop-integration skill by `@leegeunhyeok`
- update esbuild snap diff metrics by `@leegeunhyeok`
- sync upstream rolldown v1.1.2 by `@leegeunhyeok`
- deps: update napi to 3.9.3 (rolldown#9862) by `@shulaoda`
- deps: update oxc to 0.137.0 (rolldown#9856) by `@Boshen`
- re-enable default lld linker on x86_64-unknown-linux-gnu (rolldown#9855) by
`@Boshen`
- deps: bump vite-plus to 0.2.1 (rolldown#9850) by `@Boshen`
- skills: translate _config.json when encoding rolldown REPL links
(rolldown#9847) by `@IWANABETHATGUY`
- deps: update oxc_resolver and oxc_resolver_napi to 11.21.3 (rolldown#9841) by
`@Boshen`
- pin vite-plus (vp) CLI to 0.1.24 in setup-vp (rolldown#9830) by `@Boshen`
- add crate/package-level CODEOWNERS (rolldown#9819) by `@IWANABETHATGUY`
- drop unused derive_more display feature from rolldown_plugin (rolldown#9820)
by `@Boshen`
- remove auto-assign PR workflow (rolldown#9807) by `@IWANABETHATGUY`
- deps: update rollup submodule for tests to v4.62.0 (rolldown#9780) by
`@rolldown-guard[bot]`
- deps: update esbuild for tests to 0.28.1 (rolldown#9779) by
`@rolldown-guard[bot]`
- deps: update test262 submodule for tests (rolldown#9781) by
`@rolldown-guard[bot]`
- deps: update oxc to 0.136.0 (rolldown#9770) by `@Boshen`
- add pull request template (rolldown#9756) by `@sapphi-red`
- clarify `rolldown_plugin_vite_*` is compatible for the same minor
(rolldown#9774) by `@sapphi-red`
- deps: update github actions (rolldown#9745) by `@renovate[bot]`
- deps: update rust crates (rolldown#9747) by `@renovate[bot]`
- deps: update napi to v3.9.2 (rolldown#9744) by `@renovate[bot]`
- deps: update npm packages (rolldown#9746) by `@renovate[bot]`
- deps: update @napi-rs/cli and emnapi deps (rolldown#9741) by `@Brooooooklyn`
- generator: fix `vp fmt` on Windows (rolldown#9727) by `@sapphi-red`
- ban importing from `assert` and recommend `assert/strict` (rolldown#9726) by
`@sapphi-red`

Co-authored-by: leegeunhyeok <26512984+leegeunhyeok@users.noreply.github.com>