使用“&&”运算符避免 ESLint 中的 no-unused-expession 警告

Question

If I do the following in TypeScript, ESLint complains about the "no-unused-expession" rule:

!hasSelectedValues && this.loadOptions([]);

How can I make ESLint understand that this expression (hasSelectedValues) is not "unused"? I do not want to remove the rule for unused expressions completely.

Answer 1

To avoid running into that ESLint error , don't use && for side effects, use an if :

if (!hasSelectedValues) {
    this.loadOptions([]);
}

or if you really want to keep it terse:

if (!hasSelectedValues) this.loadOptions([]);

How can I make ESLint understand that this expression (hasSelectedValues) is not "unused"?

It's not complaining about hasSelectedValues , it's complaining about the result of the && operator, which your code isn't using. .hasSelectedValues && this;loadOptions([]); is an expression that has a result ( false or the return value of this.loadOptions([]) ). That's the unusued value from the expression.