Promises for hooks

changelog.md

 Notice: All 1.7.x changes are present in 2.0.x aswell
 Notice: All 1.7.x changes are present in 2.0.x aswell
 
 
 # next
 # next
+- [FEATURE] Hooks can now return promises
 #### Breaking changes
 #### Breaking changes
 - Sequelize now returns promises instead of its custom event emitter from most calls. This affects methods that return multiple values (like `findOrCreate` or `findOrInitialize`). If your current callbacks do not accept the 2nd success parameter you might be seeing an array as the first param. Either use `.spread()` for these methods or add another argument to your callback: `.success(instance)` -> `.success(instance, created)`.
 - Sequelize now returns promises instead of its custom event emitter from most calls. This affects methods that return multiple values (like `findOrCreate` or `findOrInitialize`). If your current callbacks do not accept the 2nd success parameter you might be seeing an array as the first param. Either use `.spread()` for these methods or add another argument to your callback: `.success(instance)` -> `.success(instance, created)`.
 - `.success()`/`.done()` and any other non promise methods are now deprecated (we will keep the codebase around for a few versions though). on('sql') persists for debugging purposes.
 - `.success()`/`.done()` and any other non promise methods are now deprecated (we will keep the codebase around for a few versions though). on('sql') persists for debugging purposes.

lib/hooks.js

@@ -86,7 +86,7 @@ Hooks.runHooks = function() {
         hook = hook.fn
         hook = hook.fn
       }
       }
 
 
-      hook.apply(self, fnArgs.concat(function() {
+      var maybePromise = hook.apply(self, fnArgs.concat(function() {
         tick++
         tick++
 
 
         if (!!arguments[0]) {
         if (!!arguments[0]) {
@@ -96,6 +96,16 @@ Hooks.runHooks = function() {
 
 
         return run(hooks[tick])
         return run(hooks[tick])
       }))
       }))
+
+      if (Utils.Promise.is(maybePromise)) {
+        maybePromise.spread(function () {
+          tick++
+
+          resolveArgs = Array.prototype.slice.call(arguments)
+
+          return run(hooks[tick])
+        }, reject)
+      }
     }
     }
 
 
     run(hooks[tick])
     run(hooks[tick])
@@ -129,7 +139,7 @@ Hooks.addHook = function(hookType, name, fn) {
   }
   }
 
 
   var method = function() {
   var method = function() {
-    fn.apply(this, Array.prototype.slice.call(arguments, 0, arguments.length-1).concat(arguments[arguments.length-1]))
+    return fn.apply(this, Array.prototype.slice.call(arguments, 0, arguments.length-1).concat(arguments[arguments.length-1]))
   }
   }
 
 
   // Aliases
   // Aliases

test/hooks.test.js

@@ -7219,4 +7219,48 @@ describe(Support.getTestDialectTeaser("Hooks"), function () {
       })
       })
     })
     })
   })
   })
+
+  describe('promises', function () {
+    beforeEach(function() {
+      this.User = this.sequelize.define('User', {
+        username: DataTypes.STRING,
+        mood: {
+          type: DataTypes.ENUM,
+          values: ['happy', 'sad', 'neutral']
+        }
+      })
+
+      return this.User.sync({ force: true })
+    })
+
+    it('can return a promise and modify fields', function () {
+      var self = this
+
+      this.User.beforeBulkCreate(function (daos, fields) {
+        return self.sequelize.Promise.resolve([daos, ['username']])
+      })
+
+      return this.User.bulkCreate([
+        {username: 'Bob', mood: 'cold'},
+        {username: 'Tobi', mood: 'hot'}
+      ], { fields: [], hooks: false }).success(function(bulkUsers) {
+        return self.User.all().success(function(users) {
+          expect(users[0].mood).to.equal(null)
+          expect(users[1].mood).to.equal(null)
+        })
+      })
+    })
+
+    it('can return an error by rejecting', function () {
+      var self = this
+
+      this.User.beforeCreate(function () {
+        return self.sequelize.Utils.Promise.reject("I'm afraid I can't let you do that");
+      })
+
+      return this.User.create({}).catch(function (err) {
+        expect(err).to.equal("I'm afraid I can't let you do that")
+      })
+    })
+  })
 })
 })