extract create-promise (#218)

* extract create-promise

* Update lib/create-promise.js

Co-authored-by: Matteo Collina <[email protected]>

---------

Co-authored-by: Matteo Collina <[email protected]>

lib/create-promise.js

@@ -0,0 +1,33 @@
+'use strict'
+
+/**
+ * @typedef PromiseObject
+ * @property {Promise} promise
+ * @property {PromiseConstructor["resolve"]} resolve
+ * @property {PromiseConstructor["reject"]} reject
+ */
+
+/**
+ * @returns {PromiseObject}
+ */
+function createPromise () {
+  /**
+     * @type {PromiseObject}
+     */
+  const obj = {
+    resolve: null,
+    reject: null,
+    promise: null
+  }
+
+  obj.promise = new Promise((resolve, reject) => {
+    obj.resolve = resolve
+    obj.reject = reject
+  })
+
+  return obj
+}
+
+module.exports = {
+  createPromise
+}

plugin.js

@@ -4,20 +4,10 @@ const fastq = require('fastq')
 const EE = require('events').EventEmitter
 const inherits = require('util').inherits
 const { debug } = require('./lib/debug')
+const { createPromise } = require('./lib/create-promise')
 const { AVV_ERR_READY_TIMEOUT } = require('./lib/errors')
 const { getPluginName } = require('./lib/get-plugin-name')
 
-function promise () {
-  const obj = {}
-
-  obj.promise = new Promise((resolve, reject) => {
-    obj.resolve = resolve
-    obj.reject = reject
-  })
-
-  return obj
-}
-
 function Plugin (parent, func, options, isAfter, timeout) {
   this.started = false
   this.func = func
@@ -144,7 +134,7 @@ Plugin.prototype.loadedSoFar = function () {
   let res
 
   if (!this._promise) {
-    this._promise = promise()
+    this._promise = createPromise()
     res = this._promise.promise
 
     if (!this.server) {

test/lib/create-promise.test.js

@@ -0,0 +1,55 @@
+'use strict'
+
+const { test } = require('tap')
+const { createPromise } = require('../../lib/create-promise')
+
+test('createPromise() returns an object', (t) => {
+  t.plan(3)
+  t.type(createPromise(), 'object')
+  t.equal(Array.isArray(createPromise()), false)
+  t.notOk(Array.isArray(createPromise() !== null))
+})
+
+test('createPromise() returns an attribute with attribute resolve', (t) => {
+  t.plan(1)
+  t.ok('resolve' in createPromise())
+})
+
+test('createPromise() returns an attribute with attribute reject', (t) => {
+  t.plan(1)
+  t.ok('reject' in createPromise())
+})
+
+test('createPromise() returns an attribute with attribute createPromise', (t) => {
+  t.plan(1)
+  t.ok('promise' in createPromise())
+})
+
+test('when resolve is called, createPromise attribute is resolved', (t) => {
+  t.plan(1)
+  const p = createPromise()
+
+  p.promise
+    .then(() => {
+      t.pass()
+    })
+    .catch(() => {
+      t.fail()
+    })
+  p.resolve()
+})
+
+test('when reject is called, createPromise attribute is rejected', (t) => {
+  t.plan(1)
+  const p = createPromise()
+
+  p.promise
+    .then(() => {
+      t.fail()
+    })
+    .catch(() => {
+      t.pass()
+    })
+
+  p.reject()
+})