# E0078: missing expression between parentheses

Parentheses (`(` and `)`) serve three purposes in JavaScript:

- grouping in expressions
- calling functions
- function parameters

It is a syntax error to write `(` immediately followed by `)` (with nothing between) when grouping in expressions:

    function fma(a, b, c) {
      return () + c;
    }

    const config = ();

    takeCookiesFromCookieJar()
      .then(cookies => eatCookies()
        .then(()));

To fix this error, write an expression between the parentheses:

    function fma(a, b, c) {
      return (a*b) + c;
    }

Alternatively, put the name of a function before the parentheses to call a function with no arguments:

    const config = loadConfig();

Alternatively, write the rest of your arrow function:

    takeCookiesFromCookieJar()
      .then(cookies => eatCookies()
        .then(() => putAwayCookieJar()));

Introduced in quick-lint-js version 0.2.0.

Documentation for other errors