Function warner

test/node.test.ts:86–88

(css: Root, result: Result)

test('warn() accepts options', () => {
  let warner = (css: Root, result: Result): void => {
    css.first?.warn(result, 'FIRST!', { index: 1 })
  }

  let result = postcss([warner]).process('a{}')
  is(result.warnings().length, 1)