no-meaningless-void-operator
Disallow the
void
operator except when used to discard a value.
Disallows the void
operator when its argument is already of type void
or undefined
.
Attributes
- Included in configs
- ✅ Recommended
- 🔒 Strict
- Fixable
- 🔧 Automated Fixer
- 💡 Suggestion Fixer
- 💭 Requires type information
Rule Details
The void
operator is a useful tool to convey the programmer's intent to discard a value. For example, it is recommended as one way of suppressing @typescript-eslint/no-floating-promises
instead of adding .catch()
to a promise.
This rule helps an author catch API changes where previously a value was being discarded at a call site, but the callee changed so it no longer returns a value. When combined with no-unused-expressions, it also helps readers of the code by ensuring consistency: a statement that looks like void foo();
is always discarding a return value, and a statement that looks like foo();
is never discarding a return value.
Examples of code for this rule:
- ❌ Incorrect
- ✅ Correct
void (() => {})();
function foo() {}
void foo();
(() => {})();
function foo() {}
foo(); // nothing to discard
function bar(x: number) {
void x; // discarding a number
return 2;
}
void bar(); // discarding a number
Options
This rule accepts a single object option with the following default configuration:
{
"@typescript-eslint/no-meaningless-void-operator": [
"error",
{
"checkNever": false
}
]
}
checkNever: true
will suggest removingvoid
when the argument has typenever
.