Repo: typescript-eslint Project Service Compiler Options on Non-Included Files

This reproduction shows that using the new typescript-eslint EXPERIMENTAL_useProjectService to lint a non-included file doesn't receive tsconfig.json compiler options.

npm i
cp tsconfig.baseline.json tsconfig.json
npm run lint

/Users/josh/repos/repros/.eslintrc.cjs
  0:1  error  This rule requires the `strictNullChecks` compiler option to be turned on to function correctly  @typescript-eslint/no-unnecessary-condition

Two steps must be done in the tsconfig.json to include a .eslintrc.cjs:

• Enable compilerOptions.allowJs: because it's a JavaScript extension
• Add "./.*" or similar to include: because it's a dot-file

Changing tsconfig.json in those two ways allows the project service to pick up the compiler options for the file:

cp tsconfig.working.json tsconfig.json
npm run lint

Filed as typescript-eslint/typescript-eslint#8206.