fix(tsconfig): resolve rootDirs against the config that declared them#1150
Merged
Conversation
Closes #1075. `rootDirs` entries inherited via `extends` were being normalized against the caller tsconfig's directory at `build()` time, instead of against the directory of the config that actually declared them. This broke SvelteKit projects where `tsconfig.json` extends `.svelte-kit/tsconfig.json` and the latter declares `rootDirs: ["..", "./types"]` relative to itself. Mirror the established `paths_base` pattern: normalize non-template entries at parse time against each config's own canonical directory. `build()` keeps `${configDir}` template substitution only. This also matches TypeScript's behavior (verified via `tsc --traceResolution`).
Codecov Report❌ Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## main #1150 +/- ##
==========================================
- Coverage 93.15% 93.14% -0.01%
==========================================
Files 22 22
Lines 4150 4159 +9
==========================================
+ Hits 3866 3874 +8
- Misses 284 285 +1 ☔ View full report in Codecov by Sentry. 🚀 New features to boost your workflow:
|
Merging this PR will improve performance by 4.78%
Performance Changes
Tip Curious why this is faster? Comment Comparing 
Footnotes
|
Boshen
added a commit
that referenced
this pull request
May 25, 2026
## 🤖 New release * `oxc_resolver`: 11.19.1 -> 11.19.2 * `oxc_resolver_napi`: 11.19.1 -> 11.19.2 <details><summary><i><b>Changelog</b></i></summary><p> ## `oxc_resolver` <blockquote> ## [11.19.2](v11.19.1...v11.19.2) - 2026-05-25 ### <!-- 1 -->🐛 Bug Fixes - *(tsconfig)* apply later-wins semantics for extends array ([#1156](#1156)) (by @Boshen) - *(tsconfig)* walk past a tsconfig that doesn't claim the file ([#1154](#1154)) (by @Boshen) - *(tsconfig)* let project references take priority over their parent ([#1151](#1151)) (by @Boshen) - *(tsconfig)* resolve `rootDirs` against the config that declared them ([#1150](#1150)) (by @Boshen) - *(tsconfig)* resolve `baseUrl` / `paths` against the canonical tsconfig path ([#1148](#1148)) (by @Boshen) - strip query fragments when calling `find_tsconfig` ([#1147](#1147)) (by @Boshen) - avoid panic in resolve_file for parentless paths ([#1053](#1053)) (by @Boshen) - *(dts)* strip ./ prefix from package entry when matching typesVersions ([#1051](#1051)) (by @Boshen) - *(dts)* expand Declaration to TypeScript|Declaration for package entry resolution ([#1050](#1050)) (by @Boshen) - *(dts)* prefer declaration extensions over JS in exports-resolved paths ([#1047](#1047)) (by @Boshen) - avoid wasm/wasi dead-code lint in NodePath ([#1043](#1043)) (by @Boshen) - *(napi)* replace panics with error returns to prevent WASM traps ([#1055](#1055)) (by @Boshen) ### <!-- 2 -->🚜 Refactor - remove clear_cache test that dynamically creates fixtures (by @Boshen) - move resolve and misc fixtures into fixtures/integration (by @Boshen) - replace ignored doctest with link to example (by @Boshen) - consolidate fixture directories for better test file mapping (by @Boshen) - replace `url` crate with `percent-encoding` ([#1065](#1065)) (by @Boshen) ### <!-- 4 -->⚡ Performance - *(cache)* pack CachedPathImpl::meta into a CachedMeta byte ([#1144](#1144)) (by @Boshen) - *(cache)* store canonical path as Box<Path> instead of PathBuf ([#1143](#1143)) (by @Boshen) - *(alias)* fast-reject alias entries by cached first byte ([#1142](#1142)) (by @Boshen) ### <!-- 6 -->🧪 Testing - *(tsconfig)* port lookup scenarios from typescript-go ([#1155](#1155)) (by @Boshen) - add 28 tests to improve coverage (92% → 93%) ([#1082](#1082)) (by @Boshen) ### Contributors * @Boshen * @renovate[bot] </blockquote> </p></details> --- This PR was generated with [release-plz](https://github.com/release-plz/release-plz/). Co-authored-by: oxc-guard[bot] <276638029+oxc-guard[bot]@users.noreply.github.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Closes #1075.
rootDirsentries inherited viaextendswere being normalized against the caller tsconfig's directory atbuild()time, instead of against the directory of the config that actually declared them. This broke the SvelteKit pattern wheretsconfig.jsonextends.svelte-kit/tsconfig.jsonand the latter declaresrootDirs: ["..", "./types"]relative to itself.Fix
Mirror the established
paths_basepattern: normalize non-templaterootDirsentries at parse time against each config's own canonical directory (canonical_path.parent()). Thebuild()step keeps${configDir}template substitution only, so templates still resolve against the root caller's directory as before.After this change,
extend_tsconfig's existing clone-from-parent is correct without further work — the parent's entries are already absolute by the time the child inherits them.Verification
Cross-checked against TypeScript 6.0.3 via
tsc --traceResolution:rootDirs: ["..", "./types"]declared in.svelte-kit/tsconfig.jsonagainst.svelte-kit/, exactly matching the fixed behavior.extends(node_modules/shared-config→ real-configs) — TS anchors inheritedrootDirsat the canonical path of the parent config, matching thepaths_baseprecedent landed in fix(tsconfig): resolvebaseUrl/pathsagainst the canonical tsconfig path #1148.Verified against typescript-go source (
internal/tsoptions/tsconfigparsing.go):rootDirsis declaredIsFilePath: trueandnormalizeNonListOptionValuecallsGetNormalizedAbsolutePath(value, basePath)at parse time per config;handleOptionConfigDirTemplateSubstitutionruns once afterward against the root caller's directory.New fixture
fixtures/tsconfig/cases/root-dirs-extends/mirrors the SvelteKit reproduction; new testtest_root_dirs_via_extendsfails onmain(NotFound("./$types")) and passes after the fix.