Allow promises to be returned in lifecycle hooks

Author: Clark Pan

dist/angular-data.js

@@ -7101,7 +7101,10 @@ module.exports = [function () {
             });
 
             try {
-              fn.apply(target || this, args);
+              var promise = fn.apply(target || this, args);
+              if(promise && promise.then){
+                promise.then(deferred.resolve, deferred.reject);
+              }
             } catch (err) {
               deferred.reject(err);
             }

dist/angular-data.min.js

@@ -71,7 +71,10 @@
             });
 
             try {
-              fn.apply(target || this, args);
+              var promise = fn.apply(target || this, args);
+              if(promise && promise.then){
+                promise.then(deferred.resolve, deferred.reject);
+              }
             } catch (err) {
               deferred.reject(err);
             }

src/index.js

@@ -0,0 +1,81 @@
+describe('$q decorator', function(){
+  beforeEach(module('angular-data.DS'));
+
+  it('should decorate $q', inject(function($q){
+    assert.isFunction($q.promisify);
+  }));
+
+  it('should resolve with a cb', inject(function($q, $rootScope){
+    var resolveValue = {};
+    var resolveCb = function(cb){
+      cb(null, resolveValue);
+    };
+    var resolveSpy = sinon.spy();
+
+    $q.promisify(resolveCb)().then(resolveSpy);
+    $rootScope.$digest();
+
+    assert(resolveSpy.calledWith(resolveValue));
+  }));
+
+  it('should reject with a cb', inject(function($q, $rootScope){
+    var rejectValue = {};
+    var rejectCb = function(cb){
+      cb(rejectValue);
+    };
+    var rejectSpy = sinon.spy();
+
+    $q.promisify(rejectCb)().then(null, rejectSpy);
+    $rootScope.$digest();
+
+    assert(rejectSpy.calledWith(rejectValue));
+  }));
+
+  it('should resolve with a promise', inject(function($q, $rootScope){
+    var resolveValue = {};
+    var resolveCb = function(cb){
+      return $q.when(resolveValue);
+    };
+    var resolveSpy = sinon.spy();
+
+    $q.promisify(resolveCb)().then(resolveSpy);
+    $rootScope.$digest();
+
+    assert(resolveSpy.calledWith(resolveValue));
+  }));
+
+  it('should reject with a promise', inject(function($q, $rootScope){
+    var rejectValue = {};
+    var rejectCb = function(cb){
+      return $q.reject(rejectValue);
+    };
+    var rejectSpy = sinon.spy();
+
+    $q.promisify(rejectCb)().then(null, rejectSpy);
+    $rootScope.$digest();
+
+    assert(rejectSpy.calledWith(rejectValue));
+  }));
+
+  //Typically, functions that return a promise will be wrapped with a $q.when, meaning if you were to return nothing, it would execute straight away
+  //This would mean the cb style would not work at all, as any developer that uses cb would have the function immediately resolve
+  //This just ensures that doesn't ever happen
+  it('should not resolve or reject if return value is not a promise', inject(function($q, $rootScope){
+    var resolve;
+    var cb = function(next){
+      resolve = next;
+      return true;
+    }
+    var spy = sinon.spy();
+
+    $q.promisify(cb)().finally(spy);
+    $rootScope.$digest();
+
+    assert(!spy.called);
+
+    resolve();
+    $rootScope.$digest();
+
+    assert(spy.called);
+  }));
+})