refactor queryInterface.delete to use promises rather than custom iterator

lib/query-interface.js

@@ -612,7 +612,6 @@ module.exports = (function() {
 
   QueryInterface.prototype.delete = function(dao, tableName, identifier, options) {
     var self = this
-      , restrict = false
       , cascades = []
       , sql = self.QueryGenerator.deleteQuery(tableName, identifier, null, dao.Model);
 
@@ -623,70 +622,20 @@ module.exports = (function() {
 
       for (var i = 0; i < length; i++) {
         if (dao.Model.associations[keys[i]].options && dao.Model.associations[keys[i]].options.onDelete) {
-          if (dao.Model.associations[keys[i]].options.onDelete === 'restrict') {
-            restrict = true;
-          }
-          else if (dao.Model.associations[keys[i]].options.onDelete === 'cascade' && dao.Model.associations[keys[i]].options.useHooks === true) {
-            cascades[cascades.length] = dao.Model.associations[keys[i]].accessors.get;
+          if (dao.Model.associations[keys[i]].options.onDelete === 'cascade' && dao.Model.associations[keys[i]].options.useHooks === true) {
+            cascades.push(dao.Model.associations[keys[i]].accessors.get);
           }
         }
       }
     }
 
-    return new Utils.Promise(function(resolve, reject) {
-      var tick = 0;
-      var iterate = function(err, i) {
-        if (err) {
-          return reject(err);
-        }
-
-        if (i >= cascades.length) {
-          return resolve();
-        }
-
-        dao[cascades[i]]().success(function(tasks) {
-          if (tasks === null || tasks.length < 1) {
-            if (i >= cascades.length) {
-              return resolve();
-            } else {
-              tick++;
-              return iterate(null, tick);
-            }
-          }
-
-          tasks = Array.isArray(tasks) ? tasks : [tasks];
-
-          var ii = 0;
-          var next = function(err, ii) {
-            if (!!err || ii >= tasks.length) {
-              return iterate(err);
-            }
-
-            tasks[ii].destroy().error(function(err) {
-              return iterate(err);
-            })
-            .success(function() {
-              ii++;
-
-              if (ii >= tasks.length) {
-                tick++;
-                return iterate(null, tick);
-              }
-
-              next(null, ii);
-            });
-          };
-
-          next(null, ii);
-        });
-      };
-
-      if (cascades.length > 0) {
-        iterate(null, tick);
-      } else {
-        resolve();
-      }
-    }).then(function() {
+    return Promise.reduce(cascades, function (memo, cascade) {
+      return dao[cascade]().then(function (instances) {
+        return Promise.reduce(instances, function (memo, instance) {
+          return instance.destroy();
+        }, []);
+      });
+    }, []).then(function () {
       return self.sequelize.query(sql, dao, options);
     });
   };

test/integration/hooks.test.js

@@ -5580,37 +5580,32 @@ describe(Support.getTestDialectTeaser('Hooks'), function() {
                 , beforeTask = false
                 , afterTask = false
                 , beforeMiniTask = false
-                , afterMiniTask = false;
-
+                , afterMiniTask = false
+                , VeryCustomError = function() {};
 
-              this.Projects.beforeCreate(function(project, options, fn) {
+              this.Projects.beforeCreate(function(project, options) {
                 beforeProject = true;
-                fn();
               });
 
-              this.Projects.afterCreate(function(project, options, fn) {
+              this.Projects.afterCreate(function(project, options) {
                 afterProject = true;
-                fn();
               });
 
-              this.Tasks.beforeDestroy(function(task, options, fn) {
+              this.Tasks.beforeDestroy(function(task, options) {
                 beforeTask = true;
-                fn(new Error('Whoops!'));
+                throw new VeryCustomError('Whoops!');
               });
 
-              this.Tasks.afterDestroy(function(task, options, fn) {
+              this.Tasks.afterDestroy(function(task, options) {
                 afterTask = true;
-                fn();
               });
 
-              this.MiniTasks.beforeDestroy(function(minitask, options, fn) {
+              this.MiniTasks.beforeDestroy(function(minitask, options) {
                 beforeMiniTask = true;
-                fn();
               });
 
-              this.MiniTasks.afterDestroy(function(minitask, options, fn) {
+              this.MiniTasks.afterDestroy(function(minitask, options) {
                 afterMiniTask = true;
-                fn();
               });
 
               return this.sequelize.Promise.all([
@@ -5623,14 +5618,14 @@ describe(Support.getTestDialectTeaser('Hooks'), function() {
                   project.addTask(task)
                 ]).return(project);
               }).then(function(project) {
-                return project.destroy();
-              }).catch(function() {
-                expect(beforeProject).to.be.true;
-                expect(afterProject).to.be.true;
-                expect(beforeTask).to.be.true;
-                expect(afterTask).to.be.false;
-                expect(beforeMiniTask).to.be.false;
-                expect(afterMiniTask).to.be.false;
+                return expect(project.destroy()).to.eventually.be.rejectedWith(VeryCustomError).then(function () {
+                  expect(beforeProject).to.be.true;
+                  expect(afterProject).to.be.true;
+                  expect(beforeTask).to.be.true;
+                  expect(afterTask).to.be.false;
+                  expect(beforeMiniTask).to.be.false;
+                  expect(afterMiniTask).to.be.false;
+                });
               });
             });
           });