Prerequisites

• I've read the relevant documentation
• I've searched for existing issues
• I've read the issue reproduction guide

Reproduction url

https://github.com/agneym/knip-v6-tsconfig-paths-repro

Reproduction access

• I've made sure the reproduction is publicly accessible

Good version

5.64.0

Bad version

6.0.0 and still present in latest 6.16.1

Description of the regression

In Knip v5, --tsConfig tsconfig.app.json used that tsconfig's compilerOptions.paths for module resolution. In Knip v6, the selected tsconfig is loaded, but its compilerOptions.paths do not appear to be used for resolving imports in discovery mode.

Repro commands:

git clone https://github.com/agneym/knip-v6-tsconfig-paths-repro.git
cd knip-v6-tsconfig-paths-repro
pnpm install
pnpm knip

The repo has this shape:

• tsconfig.json has no compilerOptions.paths.
• tsconfig.app.json extends tsconfig.json and defines @app/* -> ./src/*.
• knip.ts has no paths.
• src/main.ts imports src/used.ts via @app/used.
• src/unused.ts is truly unused.

Expected with:

knip --include files --tsConfig tsconfig.app.json --no-progress --reporter compact

Only the truly unused file should be reported:

src/unused.ts

Actual with Knip v6.16.1:

src/unused.ts: src/unused.ts
src/used.ts: src/used.ts

If I duplicate the alias in Knip config via paths, then v6 reports only src/unused.ts, which suggests the import itself is fine and the issue is specifically that compilerOptions.paths from the selected --tsConfig file is not feeding module resolution.

Confirmed regression:

pnpm dlx knip@5.64.0 --include files --tsConfig tsconfig.app.json --no-progress --reporter compact

reports only:

src/unused.ts

while:

pnpm dlx knip@6.0.0 --include files --tsConfig tsconfig.app.json --no-progress --reporter compact

reports both files.

Note: --use-tsconfig-files reporting no unused files is not the concern here; the FAQ explains that tsconfig files become program files and are not reported as unused. This regression is about normal discovery mode with --tsConfig not using the selected tsconfig's compilerOptions.paths for module resolution.