Function addHook

fastify.js:570–615

(name, fn)

  // wrapper that we expose to the user for hooks handling
  function addHook (name, fn) {
    throwIfAlreadyStarted('Cannot call "addHook"!')

    if (fn == null) {
      throw new errorCodes.FST_ERR_HOOK_INVALID_HANDLER(name, fn)
    }

    if (name === 'onSend' || name === 'preSerialization' || name === 'onError' || name === 'preParsing') {
      if (fn.constructor.name === 'AsyncFunction' && fn.length === 4) {
        throw new errorCodes.FST_ERR_HOOK_INVALID_ASYNC_HANDLER()
      }
    } else if (name === 'onReady' || name === 'onListen') {
      if (fn.constructor.name === 'AsyncFunction' && fn.length !== 0) {
        throw new errorCodes.FST_ERR_HOOK_INVALID_ASYNC_HANDLER()
      }
    } else if (name === 'onRequestAbort') {
      if (fn.constructor.name === 'AsyncFunction' && fn.length !== 1) {
        throw new errorCodes.FST_ERR_HOOK_INVALID_ASYNC_HANDLER()
      }
    } else {
      if (fn.constructor.name === 'AsyncFunction' && fn.length === 3) {
        throw new errorCodes.FST_ERR_HOOK_INVALID_ASYNC_HANDLER()
      }
    }

    if (name === 'onClose') {
      this.onClose(fn.bind(this))
    } else if (name === 'onReady' || name === 'onListen' || name === 'onRoute') {
      this[kHooks].add(name, fn)
    } else {
      this.after((err, done) => {
        try {
          _addHook.call(this, name, fn)
          done(err)
        } catch (err) {
          done(err)
        }
      })
    }
    return this

    function _addHook (name, fn) {
      this[kHooks].add(name, fn)
      this[kChildren].forEach(child => _addHook.call(child, name, fn))
    }
  }

  // wrapper that we expose to the user for schemas handling
  function addSchema (schema) {