feat(lint): use tsrs as the experimental default backend

bench/tsrs-lint-ecosystem.md

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+# Ecosystem correctness comparison
+
+The default `tsrs@0.22.0-ts7.1.0-beta` switch is not diagnostically equivalent to
+`oxlint-tsgolint@7.0.2005`. The representative sweep found new type-check errors in
+Hono and Vue Core, and a DOM-library compatibility change in OneSignal. These
+findings prevent a regression-free release claim.
+
+On 2026-11-06, a Linux x64/glibc Codespace ran 141 commands across 14 pinned forks
+from the [ecosystem catalog](https://github.com/vite-plus-ecosystem-ci/.github).
+The explicit type-check workload covered 2,289 files. No command timed out or
+terminated by a signal. Seven repositories had identical normalized diagnostics;
+seven had differences. This covers the selected repositories, not all 83 catalog entries.
+
+## Controls and method
+
+The comparison used three toolchains:
+
+| Control                 | Published Vite+ package                                 | Native lint backend        |
+| ----------------------- | ------------------------------------------------------- | -------------------------- |
+| Stable                  | `1.5.0`                                                 | `oxlint-tsgolint@7.0.2005` |
+| Preview with Go control | `0.0.0-commit.4fcf99edbe42fe3305dcd41dc884a4c4b7f5fd45` | `oxlint-tsgolint@7.0.2005` |
+| Default preview         | Same preview                                            | `tsrs@0.22.0-ts7.1.0-beta` |
+
+All controls used Oxlint `1.91.0`. Stable and preview with Go produced identical
+normalized lint and TypeScript diagnostics in every selected repository. This
+control separates backend differences from other preview changes.
+
+Each project retained its original frozen lockfile, application dependencies, and
+source configuration. The runner temporarily linked the published CLI, Vite,
+Oxlint, and Oxfmt into workspace importers, then restored those links. Tracked
+source files remained unchanged. The setup used each project's pinned package
+manager, with lifecycle scripts disabled. Node.js was `24.22.2`, except
+`eslint-plugin-oxlint` and `react-data-grid`, which used `26.13.0` to meet their engine requirements.
+
+Each control ran these commands:
+
+```sh
+vp lint --format json --threads 4
+vp lint --type-aware --type-check --format json --threads 4
+vp check
+```
+
+Hono retained its lint scopes: `src`, `runtime-tests`, `build`, `perf-measures`,
+`benchmarks`, and `adapters`. Hono and Vue Core do not enable type-aware linting in
+their current configurations; the explicit flags add stress coverage. React Data
+Grid enables type-aware rules but does not enable TypeScript diagnostics by default.
+
+The runner also used `vp run --no-cache` for five existing project tasks:
+`oxc-walker`'s `test:types`, `urllib`'s `typecheck`, `media-processors`'s `typecheck`,
+`react-data-grid`'s `typecheck`, and `vue-core`'s `check`. These tasks retain their
+own compiler selection. A `tsc` task does not automatically become a `tsrs` task.
+
+The runner compared sorted JSON diagnostics, including codes, severity, messages,
+files, spans, and help text. It normalized absolute project paths. Process traces
+confirmed the expected native backend in all 42 explicit type-check runs. React
+Data Grid and Vue Core required the matching optional `@vitest/browser-playwright@5.1.0`
+peer for configuration imports. No browser installation was required.
+
+## Repository results
+
+The counts below include errors and warnings from the explicit type-check workload.
+Equal counts alone do not establish equality; the comparison also checked diagnostic content.
+All source links point to immutable commits in `vite-plus-ecosystem-ci`.
+
+| Repository / commit                                                                                                                                | Files | Go diagnostics | tsrs diagnostics | Comparison                                    |
+| -------------------------------------------------------------------------------------------------------------------------------------------------- | ----: | -------------: | ---------------: | --------------------------------------------- |
+| [oxc-walker `9e520f25d`](https://github.com/vite-plus-ecosystem-ci/oxc-walker/tree/9e520f25d2bf5c3748f51d143c534fedff207147)                       |    12 |              0 |                0 | Identical diagnostics                         |
+| [eslint-plugin-oxlint `ca4b10897`](https://github.com/vite-plus-ecosystem-ci/eslint-plugin-oxlint/tree/ca4b1089757245fa9a6a6ee46341d94a218d9c05)   |    41 |              0 |                0 | Identical diagnostics                         |
+| [solid-services `add4b036b`](https://github.com/vite-plus-ecosystem-ci/solid-services/tree/add4b036b72de7e6372b07faf0aed6b3f2e506d4)               |    10 |              0 |                0 | Identical diagnostics                         |
+| [pinia-shared-state `1b1ec6109`](https://github.com/vite-plus-ecosystem-ci/pinia-shared-state/tree/1b1ec6109b6f46079e4ddb5aeb9feff1d7188c24)       |     6 |              0 |                0 | Identical diagnostics                         |
+| [urllib `91f32d53f`](https://github.com/vite-plus-ecosystem-ci/urllib/tree/91f32d53faaae34a9f09f38e402e617420bc4d15)                               |    72 |              6 |                6 | Identical diagnostics                         |
+| [anywidget `443d720b2`](https://github.com/vite-plus-ecosystem-ci/anywidget/tree/443d720b2233fff131a0f0a842b08744c8ffabd6)                         |    66 |             14 |               14 | Identical diagnostics                         |
+| [css-modules-kit `634608fdd`](https://github.com/vite-plus-ecosystem-ci/css-modules-kit/tree/634608fdd401001d1fb05511a89177acf38b8111)             |   131 |              0 |                0 | Identical diagnostics                         |
+| [media-processors `79c87cd5c`](https://github.com/vite-plus-ecosystem-ci/media-processors/tree/79c87cd5c066a0a9abea979044c38c69603a85e8)           |    22 |            101 |               91 | 10 fewer diagnostics                          |
+| [web-app-template `f9a09f3d8`](https://github.com/vite-plus-ecosystem-ci/web-app-template/tree/f9a09f3d81002372e839247c6274af43177bbeca)           |     8 |              3 |                1 | 2 fewer diagnostics                           |
+| [OneSignal-Website-SDK `5375640c0`](https://github.com/vite-plus-ecosystem-ci/OneSignal-Website-SDK/tree/5375640c001a2dc462ed1cb938520edfb9a23d07) |   298 |              8 |                9 | New DOM-library requirement                   |
+| [react-data-grid `384aedffc`](https://github.com/vite-plus-ecosystem-ci/react-data-grid/tree/384aedffc2cac013666b58b6787d888b9dde3a94)             |   127 |            302 |              300 | 2 fewer diagnostics; message changes          |
+| [vue-clamp `6f0da3991`](https://github.com/vite-plus-ecosystem-ci/vue-clamp/tree/6f0da3991f804587ba402a7ca22aec4564eab938)                         |   134 |              5 |                1 | 4 fewer recursion errors                      |
+| [hono `c91b60a25`](https://github.com/vite-plus-ecosystem-ci/hono/tree/c91b60a251186fb024557c6d55a11d8e388f179c)                                   |   457 |            474 |              476 | 2 new contextual-typing errors; span changes  |
+| [vue-core `747e8d668`](https://github.com/vite-plus-ecosystem-ci/vue-core/tree/747e8d668c4a64ae6bd9dcc74c173364f1c1490b)                           |   905 |            547 |              546 | 7 new source errors; 8 fewer recursion errors |
+
+Default `vp lint` diagnostics matched in ten repositories. Its four differences
+were OneSignal, media-processors, web-app-template, and vue-clamp. Vue Clamp's lint
+exit changed from `1` to `0` after four `TS2321` errors disappeared; one warning remained.
+The additional Hono, Vue Core, and React Data Grid differences appeared with explicit type-check flags.
+
+`vp check` passed in oxc-walker, eslint-plugin-oxlint, pinia-shared-state, and
+css-modules-kit under all controls. The other ten failed under all controls.
+Formatting stopped five of them before lint: solid-services, anywidget,
+vue-clamp, Hono, and Vue Core. These failures do not demonstrate backend failure
+or backend coverage.
+
+## Confirmed contextual-typing regression
+
+[Hono's `Style` implementation](https://github.com/vite-plus-ecosystem-ci/hono/blob/c91b60a251186fb024557c6d55a11d8e388f179c/src/helper/css/index.ts#L192)
+produces two new `TS7031` errors for `children` and `nonce` with tsrs. This reduced
+source reproduces the failure with strict type checking:
+
+```ts
+interface StyleType {
+  (args?: { children?: Promise<string>; nonce?: string }): string;
+}
+export const Style: StyleType = ({ children, nonce } = {}) => `${children}${nonce}`;
+```
+
+TypeScript `6.0.3`, TypeScript `7.0.2`, and both Go lint controls accept this source.
+The default preview and standalone tsrs report both errors. An explicit parameter
+type annotation makes all controls pass. Hono's production project also passes
+`tsc -p tsconfig.build.json --noEmit` but fails the same check with standalone tsrs.
+This confirms a compiler difference independent of Vite+ backend resolution.
+
+[Vue Core's `applyTextModel`](https://github.com/vite-plus-ecosystem-ci/vue-core/blob/747e8d668c4a64ae6bd9dcc74c173364f1c1490b/packages/runtime-vapor/src/directives/vModel.ts#L46)
+has the same default-destructuring pattern. Its `trim`, `number`, and `lazy` bindings
+produce three new `TS7031` errors. A four-line reduction with a mapped optional
+parameter passes both TypeScript versions and both Go controls, but fails both tsrs paths.
+
+## Vue Core selector types
+
+[Vue Core's scoped-style transformer](https://github.com/vite-plus-ecosystem-ci/vue-core/blob/747e8d668c4a64ae6bd9dcc74c173364f1c1490b/packages/compiler-sfc/src/style/pluginScoped.ts#L107)
+produces a new `TS5115` circular-instantiation error and two `TS7006` callback errors.
+This smaller case uses the project's locked `postcss-selector-parser@7.1.6`:
+
+```ts
+import type parser from 'postcss-selector-parser';
+export function inspect(selector: parser.Selector): void {
+  selector.each((n) => {
+    if (n.type === 'pseudo') {
+      n.nodes[0].each((ss) => {
+        void ss;
+      });
+    }
+  });
+}
+```
+
+Both TypeScript versions and both Go controls accept the reduced source. The
+default preview and standalone tsrs report `TS5115` and `TS7006`. The reduction
+uses strict mode, bundler module resolution, and `skipLibCheck: true`.
+
+## Vue Core generic conditional return type
+
+[Vue Core's `toHandlerKey`](https://github.com/vite-plus-ecosystem-ci/vue-core/blob/747e8d668c4a64ae6bd9dcc74c173364f1c1490b/packages/shared/src/general.ts#L147)
+produces a new `TS2322` when it assigns a generic function with a conditional
+return type. Both an isolated copy of the original implementation and this
+reduction reproduce the error:
+
+```ts
+declare function cache<T extends (s: string) => string>(fn: T): T;
+export const handler: <T extends string>(s: T) => T extends '' ? '' : `on${Capitalize<T>}` = cache(
+  <T extends string>(s: T) => {
+    const value = s ? `on${s}` : '';
+    return value as T extends '' ? '' : `on${Capitalize<T>}`;
+  },
+);
+```
+
+Both TypeScript versions and both Go controls accept both cases. The default
+preview and standalone tsrs reject both cases with `TS2322`. The reduction uses
+the same strict compiler options as the selector case.
+
+## OneSignal DOM-library difference
+
+[OneSignal's notification mock](https://github.com/vite-plus-ecosystem-ci/OneSignal-Website-SDK/blob/5375640c001a2dc462ed1cb938520edfb9a23d07/__test__/support/environment/TestEnvironmentHelpers.ts#L46)
+produces a new `TS2741`: the constructor lacks `Notification.maxActions`. The tsrs
+`lib.dom.d.ts` requires that static property. The tested TypeScript `6.0.3` and
+`7.0.2` libraries do not contain it.
+
+```ts
+type HasMaxActions = 'maxActions' extends keyof typeof Notification ? true : false;
+export const hasMaxActions: HasMaxActions = false;
+```
+
+The TypeScript and Go controls accept this probe. Both tsrs paths report `TS2322`.
+This establishes a library-contract difference; it does not establish that the
+new DOM declaration is incorrect. The difference affects OneSignal's existing
+configuration because it already enables TypeScript diagnostics.
+
+## Other differences and limits
+
+Media-processors, web-app-template, vue-clamp, and React Data Grid report fewer
+recursive-comparison or configuration-compatibility errors with tsrs. Vue Core
+also loses eight `TS2321` errors but adds seven production-source errors. Its total
+therefore falls from 547 to 546 despite the new failures. Fewer diagnostics are
+not classified as fixes without a separate correctness check.
+
+React Data Grid also changes expanded type text in twelve existing diagnostics.
+Vue Core changes two existing messages, and Hono moves three existing `TS2875`
+spans. These presentation changes are included in the comparison.
+
+Several errors are shared by both backends. They include urllib's six
+`Http2Stream.respond` errors, anywidget's 14 type errors, missing generated
+`video-track-processor` declarations in media-processors, and a missing translation
+file in web-app-template. The broad Hono workload includes optional benchmark
+and runtime fixtures. React Data Grid and Vue Core include test declarations
+that conflict with the overlaid toolchain's Vitest types.
+
+Only oxc-walker's existing type-check task passed. The other four tasks failed
+under every control, with matching TypeScript diagnostics after installation-path
+normalization. Vue Core initially returned `2` and then `1` as its incremental
+cache warmed; fresh build-info files produced exit `2` and identical output in
+all three controls. No task compiler was replaced by the default lint backend.
+
+This method isolates the backend while preserving application dependencies. It
+does not reproduce each repository's full build pipeline or a complete dependency
+upgrade. Shared setup and source errors must not be counted as new tsrs regressions.
+The reduced cases provide independent evidence for the new compiler failures.
+
+The primary sweep used Codespaces job `job-d8ac88c64fc64b11`. Final anywidget,
+React Data Grid, and Vue Core results came from `job-f5f12efe4b514e83`, which also
+reduced the Hono and OneSignal cases. Vue reductions used `job-cf53f53e0a2d4216` and `job-120ca876783b4213`.
+The harness, frozen dependency receipts, process traces, compiler outputs, and
+raw JSON remain outside this repository.