Function preprocess

tests/unit/data-directory/index.js:19–21

(content)

  test('option: preprocess function', async () => {
    const preprocess = function (content) {
      return content.replace('markdown', 'MARKDOWN')
    }
    const data = dataDirectory(fixturesDir, { preprocess })
    expect(data.nested.baz).toBe('I am MARKDOWN!')
  })