六.run

Compiler.prototype.run = function(callback) {
  var self = this
  var startTime = Date.now()

  self.applyPluginsAsync("before-run", self, function(err) {
    if (err) return callback(err)

    self.applyPluginsAsync("run", self, function(err) {
      if (err) return callback(err)

      self.readRecords(function(err) {
        if (err) return callback(err)

        self.compile(function onCompiled(err, compilation) {
          if (err) return callback(err)

          if (
            self.applyPluginsBailResult("should-emit", compilation) === false
          ) {
            var stats = new Stats(compilation)
            stats.startTime = startTime
            stats.endTime = Date.now()
            self.applyPlugins("done", stats)
            return callback(null, stats)
          }

          self.emitAssets(compilation, function(err) {
            if (err) return callback(err)

            if (compilation.applyPluginsBailResult("need-additional-pass")) {
              compilation.needAdditionalPass = true

              var stats = new Stats(compilation)
              stats.startTime = startTime
              stats.endTime = Date.now()
              self.applyPlugins("done", stats)

              self.applyPluginsAsync("additional-pass", function(err) {
                if (err) return callback(err)
                self.compile(onCompiled)
              })
              return
            }

            self.emitRecords(function(err) {
              if (err) return callback(err)

              var stats = new Stats(compilation)
              stats.startTime = startTime
              stats.endTime = Date.now()
              self.applyPlugins("done", stats)
              return callback(null, stats)
            })
          })
        })
      })
    })
  })
}