ESLint activate option to notify “Object is possibly null”

For some reason, my .eslintrc.json has some option, or has a lack of some option to catch the warning

Object is possibly ‘null’

What I need to change to eslint notify my about this warning?

IMPORTANT this is on my unit tests, so adding strictNullChecks does not work for my project, that why I asked if eslint has an option for that.

{
  "settings": {
    "react": {
      "version": "latest"
    }
  },
  "env": {
    "browser": true,
    "es2021": true
  },
  "extends": ["eslint:recommended", "plugin:react/recommended", "plugin:@typescript-eslint/recommended", "prettier"],
  "parser": "@typescript-eslint/parser",
  "parserOptions": {
    "ecmaFeatures": {
      "jsx": true
    },
    "ecmaVersion": 12,
    "sourceType": "module"
  },
  "plugins": ["react", "@typescript-eslint"],
  "rules": {
    "@typescript-eslint/no-inferrable-types": "off"
  },
  "ignorePatterns": ["dist/*"]
}

My tsconfig.json

{
  "exclude": ["lib/**/*.spec.tsx", "lib/**/*.stories.tsx", "lib/**/*.styles.tsx", "settings/**/*", "dist/**/*"],
  "compilerOptions": {
    "skipLibCheck": true,
    "target": "es5",
    "lib": ["es5", "dom"],
    "jsx": "react",
    "declaration": true,
    "declarationMap": true,
    "sourceMap": true,
    "outDir": "dist",
    "rootDirs": ["lib"],
    "strict": true,
    "moduleResolution": "node",
    "esModuleInterop": true,
    "forceConsistentCasingInFileNames": true,
    "strictNullChecks": true
  }
}

Answer

The problem was on the line:

"exclude": ["lib/**/*.spec.tsx", ...

Because of that, the tests are being ignored.