set 'no-unused-vars' prop value 'error' but doesn't work

[Span134]

Expected results

show error 'someValue is assigned but never used' and project failed.

What happened?
only warn tip and project still run sucessed.

Steps to reproduce

1. npx react-native init AwesomeTSProject --template react-native-template-typescript
2. edit App.js add 'const someValue = 1'
3. edit eslintrc.js 'rules: {
   "no-unused-vars": "error",
   "@typescript-eslint/no-unused-vars": ["error"]
   }'
4. yarn android
5. project still run successed! It is not my expected results ! I want it show error 'someValue is assigned but never used' and project run failed.