noMeaninglessVoidOperator (JavaScript)

Language JavaScript (and super languages)

Summary

Diagnostic Category: lint/nursery/noMeaninglessVoidOperator
This rule has an unsafe fix.
The default severity of this rule is information.
This rule belongs to the following domains:
- types
Sources:
- Same as @typescript-eslint/no-meaningless-void-operator

How to configure

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{
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  "linter": {
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    "rules": {
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      "nursery": {
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        "noMeaninglessVoidOperator": "error"
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      }
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    }
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  }
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}

Description

Disallow void when it does not discard a call’s return value or a thenable.

Using void communicates that a value is deliberately ignored. Applying it to a call that already returns void or undefined obscures that intent and can hide changes to the called API. Non-call operands are also reported, except for thenables and the common void 0 idiom.

Examples

Invalid

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declare function log(): void;
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void log();

/invalid-call.ts:2:1 lint/nursery/noMeaninglessVoidOperator  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ This void operator is unnecessary.
  
    1 │ declare function log(): void;
  > 2 │ void log();
      │ ^^^^^^^^^^
    3 │ 
  
  ℹ This call already returns void or undefined.
  
  ℹ Use void to explicitly discard a call's return value or a thenable.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.
  
  ℹ Unsafe fix: Remove the void operator.
  
    1 1 │   declare function log(): void;
    2   │ - void·log();
      2 │ + (log());
    3 3 │

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void 1;

/invalid-value.js:1:1 lint/nursery/noMeaninglessVoidOperator  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ This void operator is unnecessary.
  
  > 1 │ void 1;
      │ ^^^^^^
    2 │ 
  
  ℹ This operand is neither a function call nor a thenable.
  
  ℹ Use void to explicitly discard a call's return value or a thenable.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.
  
  ℹ Unsafe fix: Remove the void operator.
  
    1   │ - void·1;
      1 │ + (1);
    2 2 │

Valid

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declare function value(): number;
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void value();
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void Promise.resolve();
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void 0;