Plugin validate

[zce]

wrapper.js

/**
 * Wrapper plugin
 * @param  {Function} plugin Plugin function
 * @return {Function}        Plugin function
 */
const defaultPlugin = (files, app, next) => next()

module.exports = plugin => {
  if (typeof plugin !== 'function') return defaultPlugin

  const fnStr = plugin.toString()
  const matches = /\(\s*([\s\S]*?)\s*\)/.exec(fnStr)

  if (!matches) return defaultPlugin

  const params = matches[1].split(/\s*,\s*/)

  if (params.length !== 3) return defaultPlugin

  // https://github.com/goatslacker/get-parameter-names/blob/master/index.js
  const code = fnStr.replace(/((\/\/.*$)|(\/\*[\s\S]*?\*\/))/mg, '')

  const regexp = new RegExp(`${params[2]}\\(\\s*\\)`)
  return regexp.test(code) ? plugin : defaultPlugin
}

[zce]

wrapper.test.js

const assert = require('assert')
const plugin = require('../../lib/plugin')

describe('lib/plugin', () => {
  it('Should return default plugin when input plugin is invaild', () => {
    assert.equal(
      undefined,
      plugin('')(1, 2, () => {})
    )
  })

  it('Should return default plugin when input plugin is invaild', () => {
    assert.equal(
      undefined,
      plugin(foo => {
        return 'fake'
      })(1, 2, () => {})
    )
  })

  it('Should return default plugin when input plugin is invaild', () => {
    assert.equal(
      undefined,
      plugin((foo, bar) => {
        return 'fake'
      })(1, 2, () => {})
    )
  })

  it('Should return default plugin when input plugin is invaild', () => {
    assert.equal(
      undefined,
      plugin((foo, bar, baz) => {
        return 'fake'
      })(1, 2, () => {})
    )
  })

  it('Should return default plugin when input plugin is invaild', () => {
    assert.equal(
      undefined,
      plugin((foo, bar, baz) => {
        console.log()
        return 'fake'
      })(1, 2, () => {})
    )
  })

  it('Should return input plugin when input plugin is vaild', () => {
    assert.equal(
      'fake',
      plugin((foo, bar, baz) => {
        baz()
        return 'fake'
      })(1, 2, () => {})
    )
  })
})