Linting files outside tsconfig rootDir

[bno1]

I have rootDir: src/ in tsconfig.json and test files in a separate directory named spec/. Everything works as expected when editing files in src/, but I don't get lint messages from typescript-eslint-language-service when editing files in spec/. I do get typescript errors though. eslint src/ spec/ --ext '.ts' works fine.

Project directory structure:

$ tree
.
├── .eslintignore
├── .eslintrc.js
├── .git
├── .gitignore
├── jakefile.js
├── lib
│   ├── <build outputs>
├── node_modules
├── package.json
├── .prettierrc.js
├── spec
│   ├── <tests>
├── src
│   ├── <sources>
├── tsconfig.json

tsconfig.json

{
  "include": [
    "src/**/*"
  ],
  "compilerOptions": {
    "declaration": true,
    "declarationMap": true,
    "outDir": "lib/",
    "rootDir": "src/",
    "composite": true,
    "plugins": [
      {
        "name": "typescript-eslint-language-service"
      }
    ]
  }
}

.eslintrc

module.exports = {
  root: true,
  parser: '@typescript-eslint/parser',
  plugins: [
    '@typescript-eslint',
  ],
  extends: [
    'eslint:recommended',
    'plugin:@typescript-eslint/eslint-recommended',
    'plugin:@typescript-eslint/recommended',
    'prettier/@typescript-eslint',
    'plugin:prettier/recommended',
  ],
};