lambda-service/src/UserConfig.js

import { join } from 'path'
import requireindex from 'requireindex'
import chalk from 'chalk'
import didyoumean from 'didyoumean'
import { cloneDeep } from 'lodash'
import signale from 'signale'
import getUserConfig, {
  getConfigPaths,
  getConfigFile,
  getConfigByConfigFile,
  cleanConfigRequireCache
} from 'lambda-base-core/lib/getUserConfig'
import { watch, unwatch } from './getConfig/watch'
import isEqual from './isEqual'

class UserConfig {
  static getConfig(opts = {}) {
    const { cwd, service } = opts
    return getUserConfig({
      cwd,
      defaultConfig: service.applyPlugins('modifyDefaultConfig', {
        initialValue: {}
      })
    })
  }

  constructor(service) {
    this.service = service
    this.configFailed = false
    this.config = null
    this.file = null
    this.relativeFile = null
    this.watch = watch
    this.unwatch = unwatch
    this.initConfigPlugins()
  }

  initConfigPlugins() {
    // 处于该文件夹下的文件都默认加载
    const map = requireindex(join(__dirname, 'getConfig/configPlugins'))
    let plugins = Object.keys(map).map(key => {
      return map[key].default
    })
    plugins = this.service.applyPlugins('_registerConfig', {
      initialValue: plugins
    })
    this.plugins = plugins.map(p => p(this))
  }

  printError(messages) {
    if (this.service.printError) this.service.printError(messages)
  }

  getConfig(opts = {}) {
    const { paths, cwd } = this.service
    const { force, setConfig } = opts
    const defaultConfig = this.service.applyPlugins('modifyDefaultConfig', {
      initialValue: {}
    })

    const file = getConfigFile(cwd)
    this.file = file
    if (!file) {
      return defaultConfig
    }

    // 强制读取，不走 require 缓存
    if (force) {
      cleanConfigRequireCache(cwd)
    }

    let config = null
    const relativeFile = file.replace(`${paths.cwd}/`, '')
    this.relativeFile = relativeFile

    const onError = (e, file) => {
      const msg = `配置文件 "${file.replace(
        `${paths.cwd}/`,
        ''
      )}" 解析出错，请检查语法。
\r\n${e.toString()}`
      this.printError(msg)
      throw new Error(msg)
    }

    config = getConfigByConfigFile(file, {
      defaultConfig,
      onError
    })

    config = this.service.applyPlugins('_modifyConfig', {
      initialValue: config
    })

    // Validate
    for (const plugin of this.plugins) {
      const { name, validate } = plugin
      if (config[name] && validate) {
        try {
          plugin.validate.call({ cwd }, config[name])
        } catch (e) {
          // 校验出错后要把值设到缓存的 config 里，确保 watch 判断时才能拿到正确的值
          if (setConfig) {
            setConfig(config)
          }
          this.printError(e.message)
          throw new Error(`配置 ${name} 校验失败, ${e.message}`)
        }
      }
    }

    // 找下不匹配的 name
    const pluginNames = this.plugins.map(p => p.name)
    Object.keys(config).forEach(key => {
      if (!pluginNames.includes(key)) {
        if (opts.setConfig) {
          opts.setConfig(config)
        }
        const affixmsg = `选择 "${pluginNames.join(', ')}" 中的一项`
        const guess = didyoumean(key, pluginNames)
        const midMsg = guess ? `你是不是想配置 "${guess}" ？ 或者` : '请'
        const msg = `"${relativeFile}" 中配置的 "${key}" 并非约定的配置项，${midMsg}${affixmsg}`
        this.printError(msg)
        throw new Error(msg)
      }
    })

    return config
  }

  setConfig(config) {
    this.config = config
  }

  watchWithDevServer() {
    // 配置插件的监听
    for (const plugin of this.plugins) {
      if (plugin.watch) {
        plugin.watch()
      }
    }

    // 配置文件的监听
    this.watchConfigs((event, path) => {
      signale.debug(`[${event}] ${path}`)
      try {
        const newConfig = this.getConfig({
          force: true,
          setConfig: newConfig => {
            this.config = newConfig
          }
        })

        // 从失败中恢复过来，需要 reload 一次
        if (this.configFailed) {
          this.configFailed = false
          this.service.refreshBrowser()
        }

        const oldConfig = cloneDeep(this.config)
        this.config = newConfig

        for (const plugin of this.plugins) {
          const { name } = plugin
          if (!isEqual(newConfig[name], oldConfig[name])) {
            this.service.config[name] = newConfig[name]
            this.service.applyPlugins('onConfigChange', {
              args: {
                newConfig
              }
            })
            if (plugin.onChange) {
              plugin.onChange(newConfig, oldConfig)
            }
          }
        }
      } catch (e) {
        this.configFailed = true
        console.error(chalk.red(`watch handler failed, since ${e.message}`))
        console.error(e)
      }
    })
  }

  watchConfigs(handler) {
    const { cwd } = this.service
    const watcher = this.watch('CONFIG_FILES', getConfigPaths(cwd))
    if (watcher) {
      watcher.on('all', handler)
    }
  }
}

export default UserConfig