close
Rslint

    no-unnecessary-boolean-literal-compare

    Configuration

    rslint.config.ts
    import { defineConfig, ts } from '@rslint/core';

export default defineConfig([
  ts.configs.recommended,
  {
    rules: {
      '@typescript-eslint/no-unnecessary-boolean-literal-compare': 'error',
    },
  },
]);

    Rule Details

    Disallow unnecessary equality comparisons against boolean literals.

    Comparing a boolean value to true or false is redundant. The value can be used directly or negated instead. This rule flags such comparisons and provides auto-fixes.

    Options

    • allowComparingNullableBooleansToTrue (default: true): When set to true, allows nullableVar === true or nullableVar !== true comparisons for nullable boolean types (boolean | null | undefined). Set to false to flag these comparisons.
    • allowComparingNullableBooleansToFalse (default: true): When set to true, allows nullableVar === false or nullableVar !== false comparisons for nullable boolean types. Set to false to flag these comparisons and suggest using the ?? operator instead.
    • allowRuleToRunWithoutStrictNullChecksIKnowWhatIAmDoing (default: false): When set to true, allows the rule to run even when strictNullChecks is not enabled. By default, the rule reports an error if strictNullChecks is off.

    Examples of incorrect code for this rule:

    declare const someCondition: boolean;
if (someCondition === true) {
}
if (someCondition !== true) {
}
if (someCondition === false) {
}

    Examples of incorrect code with { allowComparingNullableBooleansToTrue: false }:

    declare const nullableFlag: boolean | undefined;
if (nullableFlag === true) {
}

    Examples of incorrect code with { allowComparingNullableBooleansToFalse: false }:

    declare const nullableFlag: boolean | null;
if (nullableFlag === false) {
}

    Examples of correct code for this rule:

    declare const someCondition: boolean;
if (someCondition) {
}
if (!someCondition) {
}

declare const nullableFlag: boolean | null;
if (nullableFlag === true) {
} // allowed by default for nullable booleans

    Original Documentation