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no-undefined-return-type

Disallows undefined return types on functions.

Rule Details​

A function that only returns undefined is confusing and likely to be a mistake, since a function that returns nothing should have a return type of void.

// Bad
function foo(): undefined {
  return;
}

// Good
function foo(): void {
  return;
}

// Bad
function foo() {
  return undefined;
}

// Good
function foo() {
  return;
}

Options and Defaults​

{
  "rules": {
    "complete/no-undefined-return-type": "error"
  }
}

This rule is not configurable.

Resources​