[no-undef] No-undef error on user-defined Typescript type guards

[victorgarciaesgi]

• I have tried restarting my IDE and the issue persists.
• I have updated to the latest version of the packages.
• I have read the FAQ and my problem is not listed.

Repro

{
  "rules": {
    '@typescript-eslint/no-useless-constructor': 'error',
    '@typescript-eslint/no-unused-vars': 'off',
    '@typescript-eslint/explicit-function-return-type': 'off',
    '@typescript-eslint/no-explicit-any': 'off',
    '@typescript-eslint/no-use-before-define': 'off',
    '@typescript-eslint/interface-name-prefix': 'off',
    '@typescript-eslint/no-var-requires': 'off',
    '@typescript-eslint/no-namespace': 'off',
    '@typescript-eslint/camelcase': 'off',
    '@typescript-eslint/no-empty-function': 'off',
    '@typescript-eslint/ban-ts-ignore': 'off',
    '@typescript-eslint/explicit-module-boundary-types': 'off',
    '@typescript-eslint/ban-ts-comment': 'off',
    '@typescript-eslint/no-non-null-assertion': 'off',
  }
}

@Component
export default class Column extends Vue {
  isColumnString(column: TableColumn): column is string {
                                   //   ^^^^^ 'column' is not defined (eslint: no-undef)
    return typeof this.column === 'string';
  }
}

Expected Result

Actual Result

Versions

package	version
@typescript-eslint/eslint-plugin	4.0.1
@typescript-eslint/parser	4.0.1
TypeScript	4.0.2
ESLint	7.8.0
node	12.18.0

[jacekkarczmarczyk]

Is this bug related/duplicate?

[vvscode]

@jacekkarczmarczyk in fact it's another problem, but it might be caused with same reason

[vvscode]

Repo with demo : https://github.com/vvscode/ts--eslint-parser-error-demo