v4: move to TypeScript 7, framework support via content mappers by johnsoncodehk · Pull Request #103 · johnsoncodehk/tsslint

johnsoncodehk · 2026-09-02T09:38:46Z

Summary

TSSLint v4 runs lint rules on TypeScript 7's checker (tsgo) and removes the Volar-based framework support. Framework files come back through TypeScript's own content mapper (tsconfig contentMappers) instead of per-framework CLI flags, so the tsconfig is the single source of truth. This PR is the first milestone: the CLI engine swap and the Volar removal.

Quick start

tsslint --project tsconfig.json   # no --vue-project etc., no typescript install needed for linting

// tsconfig.json (framework files, once content mapper support lands; see Remaining work)
{
  "contentMappers": [
    { "package": "@vue/content-mapper", "extensions": [".vue"], "options": { "target": 3.5 } }
  ]
}

Breaking changes

@tsslint/cli bundles its own engine. It depends on typescript-native-bridge (exact-pinned 6.0.3-bridge.16.tsgo.7.0.2) instead of a typescript peer dependency. Diagnostics come from the tsgo 7.0.2 checker and can differ from TS 6 in edge cases.
--vue-project, --vue-vine-project, --mdx-project, --astro-project and --ts-macro-project are removed, together with @volar/language-core, @volar/language-hub and @volar/typescript. Declare contentMappers in the tsconfig instead; there is no replacement flag.
Custom module resolvers and JS custom transformers are not honoured by the bridge, so remapping imports to other files on disk has no effect.
musl (Alpine) is not supported. The bridge links a glibc native binary. Node.js 22.6+ is unchanged.
Peak memory on checker-heavy runs is about 1.9× v3.
Existing caches are invalidated. The cache key no longer carries languages.

Remaining work

tsslint

Content mapper support: diagnostics mapped back to the original file through spanMap, fixes offered only on Exact / Verbatim spans.
Move from typescript-native-bridge to the TypeScript 7.1 API (typescript/async, typescript/ast), so TSSLint no longer depends on any TypeScript 5/6 API surface.
Rebuild @tsslint/typescript-plugin and the VS Code extension on the TypeScript 7 LSP extension points (LSP middleware, content mapper registration). Until then editor diagnostics for framework files keep the v3 setup.

Done

Engine

@tsslint/cli runs on typescript-native-bridge, a drop-in for the classic typescript API surface backed by tsgo; require.resolve('typescript') points at the bridge.

Volar removal

The five framework flags, the proxy language service and diagnostic mapping are removed (−1,497 lines), with packages/cli/lib/languagePlugins.ts and fixtures/meta-frameworks.
The languages plumbing left in the cache layer is removed.
Untracked tsgo / relay experiment artifacts are cleaned up.

Docs

docs/migration-v4.md: breaking changes, flag → contentMappers mapping, engine behavior, editor status and availability.
README requirements updated (bundled engine, no typescript pin, musl unsupported).

Tests

Full test suite passes, including the compat-eslint bench (107 rules × 33 files, clean parity) and upstream scope-manager (212/225, no regressions).
npm run lint on the repo itself: 59 passed.
Fixture output identical to the TS 6.0.3 baseline (no diagnostic drift on this corpus).

Notes

typescript-native-bridge needs Node ≥ 20.19, below the CLI's existing 22.6 requirement.
@tsslint/core typings are declared against stock typescript, so cross-package boundaries use type-only casts (ts as unknown as typeof import('typescript')); the runtime object is the same.

pnpm run build && npm run lint

References

Content mapper hook: Content mappers microsoft/typescript-go#4712 (merged; development has since moved to microsoft/TypeScript)
Migration guide: docs/migration-v4.md

- @tsslint/cli now depends on typescript-native-bridge (pinned 6.0.3-bridge.15.tsgo.7.0.2) instead of the typescript peer dep; type checking runs on the TS 7 (tsgo) engine - Remove --vue-project/--vue-vine-project/--mdx-project/--astro-project/ --ts-macro-project flags and the Volar language plugin wiring (@volar/language-core, @volar/language-hub, @volar/typescript) - Meta-framework support will be provided by the TS 7.1 content mapper (tsconfig contentMappers) once TNB rebases onto tsgo 7.1 - Remove fixtures/meta-frameworks and untracked tsgo/relay experiments

The file was deleted with the Volar wiring; the hardcoded corpus list in packages/compat-eslint/test/bench/dogfood-corpus.ts still referenced it, failing lazy-estree.test.js with ENOENT in CI.

…lumbing - packages/cli now pins typescript-native-bridge 6.0.3-bridge.16.tsgo.7.0.2 - remove the languages parameter from the cache layer (dead since the Volar removal); the cache key no longer carries it, which also invalidates existing caches

- README: real framework-support section (tsconfig contentMappers), updated requirements (bundled engine, no typescript pin, musl unsupported) - docs/migration-v4.md: breaking changes, flag -> contentMappers mapping, engine behavior notes, editor status, availability gates

TypeScript 7 has no tsserver plugin API, so @tsslint/typescript-plugin and the VS Code extension built on it cannot work.

- Build the workspace with typescript@7.1.0-beta (module nodenext, Node >= 22.12 for require(esm)); drop typescript-native-bridge. - @tsslint/types: SourceFile from typescript/ast, Program/Checker/ DiagnosticCategory from typescript/sync. RuleContext gains `checker` (TS7 programs have no getTypeChecker); LinterContext is { typescript, getProgram }. - @tsslint/core: lint() takes { program, checker, file } instead of a file name resolved through a LanguageService. - Add tools/estree-oracle, a private test-only package pinning typescript@6 + typescript-eslint as the parity reference. - Port core tests to real TS7 projects; drop the BuilderProgram POC.

tsl and tslint are built on the TypeScript 5/6 API and cannot run on TS7. The eslint, ignore, category and diagnostics plugins now use typescript/ast and typescript/sync.

- lazy-estree / tokens / ts-ast-scan read typescript/ast. TS7 shape differences are handled in lib/ts.ts helpers: postfixToken for ?/!, ModuleDeclaration.keyword, phaseModifier for type-only imports, heritage clauses parsed as TypeReference, synthesized (Reparsed) nodes, nameless array-binding holes, EndOfFile/JSDoc kinds. - Scope analysis uses @typescript-eslint/scope-manager's analyze(), built lazily on first scopeManager read, replacing TsScopeManager. - parserServices type queries go through the project checker. - Parity tests compare against typescript-estree running on its own TypeScript 6 copy (tools/estree-oracle), bridged by node ranges. Tests depending on @typescript-eslint/eslint-plugin or the vendored scope-manager suite are removed: typescript-eslint cannot load TS7. - dogfood: register all rules before the first file is linted, so the shared traversal sees every rule (previously only the first one ran).

- lint through typescript/sync snapshots; project file names come from the configured project so content-mapped files (e.g. .vue) are included - replace the BuilderProgram incremental state with a program fingerprint (cache format v3) - map diagnostics back to original files via SourceFile.spanMap; drop diagnostics that only cover generated code - apply --fix only when every edit of a fix maps exactly - render with the TS7 formatDiagnosticsWithColorAndContext

…uide

johnsoncodehk · 2026-10-22T11:05:35Z

/release alpha 4.0.0

github-actions · 2026-10-22T11:05:59Z

Alpha release failed, see https://github.com/johnsoncodehk/tsslint/actions/runs/39767990607

johnsoncodehk · 2026-10-22T11:24:01Z

/release alpha 4.0.0

github-actions · 2026-10-22T11:24:26Z

Alpha release failed, see https://github.com/johnsoncodehk/tsslint/actions/runs/39770287974

johnsoncodehk · 2026-10-22T11:31:24Z

/release alpha 4.0.0

github-actions · 2026-10-22T11:31:48Z

Alpha release failed, see https://github.com/johnsoncodehk/tsslint/actions/runs/39771220489

johnsoncodehk · 2026-10-22T11:38:39Z

/release alpha 4.0.0

github-actions · 2026-10-22T11:39:48Z

Published 4.0.0-alpha.0 (dist-tag alpha) from f7d6918:

Record the version published from f7d6918 by release run 39772141598, so the next `prerelease` release is 4.0.0-alpha.1. Only workspace specifiers change in pnpm-lock.yaml.

- Every package that loads `typescript/sync` / `typescript/ast` now depends on typescript 7.1.0-beta instead of peering on it. TSSLint's checker is its own engine; as a peer, pnpm resolved it to a host project's TS 6 and `require('typescript/sync')` failed. - @tsslint/config and @tsslint/compat-eslint declare an optional eslint peer (>=9.39.0 <10.0.0). importESLintRules() loads core rules from `node_modules/eslint/lib/rules`, and both packages expose ESLint types. - @tsslint/config peers on @tsslint/compat-eslint via `workspace:*`, so the published range always matches the release (it was `^3.0.0`).

…kind scans ParenthesizedExpression, ParenthesizedType and ComputedPropertyName are pass-through in convertChildInner: materialise returns the inner ESTree. The scan relied on the child's target equalling the parent's to skip the re-entry, but when the inner is a wrapper head (`(a?.b)` -> ChainExpression, `(typeof import('x'))` -> TSTypeQuery) the parens level expands the chain and leaves its tail as parentTarget, so the child's visit entered the same chain again. In CPA and wildcard mode every listener on those nodes fired twice (three times under `((a?.b))`), e.g. no-non-null-asserted-optional-chain reported `(a?.b)!` twice. The three kinds now join the structural pass-through list and recurse with the parent's target unchanged.

…ession typescript-estree treats a non-null assertion that ends an optional chain (`a?.b!`, `a?.()!`, `a?.b.c!`, `a?.b!!`) as the chain's outermost link and wraps it in ChainExpression. The lazy converter only wrapped Member/CallExpression, so these produced a bare TSNonNullExpression and rules keyed on `ChainExpression > TSNonNullExpression` - notably no-non-null-asserted-optional-chain - silently missed them. isOutermostOptionalChain now accepts NonNullExpression (the ts-ast-scan ChainExpression predicate shares it), and TSNonNullExpression goes through wrapChainIfNeeded like the other links. Tests: lazy-estree-review-bugs compares 13 chain/non-null shapes with typescript-estree, plus parent links, bottom-up materialise and dispatch order for `a?.b!`; compat-pipeline runs the real no-non-null-asserted-optional-chain rule and requires the same reports as ESLint on typescript-eslint's parser. The estree-oracle test package now carries @typescript-eslint/eslint-plugin for that.

johnsoncodehk added 13 commits September 2, 2026 17:38

Remove languagePlugins.ts from dogfood corpus

99bb697

The file was deleted with the Volar wiring; the hardcoded corpus list in packages/compat-eslint/test/bench/dogfood-corpus.ts still referenced it, failing lazy-estree.test.js with ENOENT in CI.

chore: remove TS server plugin and VS Code extension

7f38675

TypeScript 7 has no tsserver plugin API, so @tsslint/typescript-plugin and the VS Code extension built on it cannot work.

feat(config)!: port config to TypeScript 7, drop tsl/tslint compat

d49814e

tsl and tslint are built on the TypeScript 5/6 API and cannot run on TS7. The eslint, ignore, category and diagnostics plugins now use typescript/ast and typescript/sync.

style: dprint format

bff8377

chore: adapt fixtures and repo lint config to TypeScript 7

1c6346c

ci: run on Node 24 and the TypeScript 7 test suite

0bf064e

docs: describe the TypeScript 7 port in the README and v4 migration g…

f7d6918

…uide

johnsoncodehk changed the title ~~v4: embed typescript-native-bridge, drop Volar-based framework support~~ v4: move to TypeScript 7, framework support via content mappers Oct 22, 2026

johnsoncodehk and others added 8 commits October 22, 2026 19:46

Merge branch 'master' into v4

ba44bef

v4.0.0-alpha.0

ae10369

Record the version published from f7d6918 by release run 39772141598, so the next `prerelease` release is 4.0.0-alpha.1. Only workspace specifiers change in pnpm-lock.yaml.

v4.0.0-alpha.1

b82aa03

Merge branch 'master' into v4

1b29171

docs(migration-v4): TypeScript 7 is a direct dependency

b8bb411

docs: TypeScript 7 is bundled, drop it from install commands

e479bbf

Navigation Menu

Repository navigation

v4: move to TypeScript 7, framework support via content mappers - #103

v4: move to TypeScript 7, framework support via content mappers#103
johnsoncodehk wants to merge 22 commits into
masterfrom
v4

johnsoncodehk commented Sep 2, 2026 •

edited

Loading

Uh oh!

johnsoncodehk commented Oct 22, 2026

Uh oh!

github-actions Bot commented Oct 22, 2026

Uh oh!

johnsoncodehk commented Oct 22, 2026

Uh oh!

github-actions Bot commented Oct 22, 2026

Uh oh!

johnsoncodehk commented Oct 22, 2026

Uh oh!

github-actions Bot commented Oct 22, 2026

Uh oh!

johnsoncodehk commented Oct 22, 2026

Uh oh!

github-actions Bot commented Oct 22, 2026

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

Conversation

johnsoncodehk commented Sep 2, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Quick start

Breaking changes

Remaining work

tsslint

Engine

Volar removal

Docs

Tests

Notes

References

Uh oh!

johnsoncodehk commented Oct 22, 2026

Uh oh!

github-actions Bot commented Oct 22, 2026

Uh oh!

johnsoncodehk commented Oct 22, 2026

Uh oh!

github-actions Bot commented Oct 22, 2026

Uh oh!

johnsoncodehk commented Oct 22, 2026

Uh oh!

github-actions Bot commented Oct 22, 2026

Uh oh!

johnsoncodehk commented Oct 22, 2026

Uh oh!

github-actions Bot commented Oct 22, 2026

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

johnsoncodehk commented Sep 2, 2026 •

edited

Loading