Function prepare

test/visitor.test.ts:729–738

(result)

    },
    postcssPlugin: 'test',
    prepare(result) {
      return {
        Once() {
          root = true
        },
        Rule(rule) {
          rule.selector = basename(result.opts.from ?? '')
        }
      }
    }
  }
  is(
    postcss([plugin]).process('a{ color: black }', { from: 'a.css' }).css,