typescript/no-unnecessary-boolean-literal-compare Suspicious

💭 This rule requires type information.

🚧 An auto-fix is still under development.

What it does

This rule disallows unnecessary equality comparisons with boolean literals.

Why is this bad?

Comparing boolean values to boolean literals is unnecessary when the comparison can be eliminated. These comparisons make code more verbose without adding value.

Examples

Examples of incorrect code for this rule:

declare const someCondition: boolean;

if (someCondition === true) {
  // ...
}

if (someCondition === false) {
  // ...
}

if (someCondition !== true) {
  // ...
}

if (someCondition !== false) {
  // ...
}

const result = someCondition == true;

Examples of correct code for this rule:

declare const someCondition: boolean;

if (someCondition) {
  // ...
}

if (!someCondition) {
  // ...
}

// Comparisons with non-boolean types are allowed
declare const someValue: unknown;
if (someValue === true) {
  // ...
}

Configuration

This rule accepts a configuration object with the following properties:

allowComparingNullableBooleansToFalse

type: boolean

default: true

Whether to allow comparing nullable boolean expressions to false. When false, x === false where x is boolean | null will be flagged.

allowComparingNullableBooleansToTrue

type: boolean

default: true

Whether to allow comparing nullable boolean expressions to true. When false, x === true where x is boolean | null will be flagged.

allowRuleToRunWithoutStrictNullChecksIKnowWhatIAmDoing

type: boolean

default: false

Whether to allow this rule to run without strictNullChecks enabled. This is not recommended as the rule may produce incorrect results.

How to use

To enable this rule in the CLI or using the config file, you can use:

CLI

oxlint --type-aware --deny typescript/no-unnecessary-boolean-literal-compare

Config (.oxlintrc.json)

{
  "rules": {
    "typescript/no-unnecessary-boolean-literal-compare": "error"
  }
}

References

• Rule Source