fix: fix updateGroup throwing an error if an empty update object wa…

…s provided in curried as well as uncurried version

CHANGELOG.md

@@ -6,6 +6,7 @@
 #### Bugfixes
 
 * fix missing union case in typing of `updateArray` update function that causes a compile error if used inside an `updateGroup` ([fa7dccc](https://github.com/MrWolfZ/ngrx-forms/commit/fa7dccc))
+* fix `updateGroup` throwing an error if an empty update object was provided in curried as well as uncurried version
 
 <a name="2.1.2"></a>
 ### 2.1.2

src/state.spec.ts

@@ -1,4 +1,4 @@
-import { cast, createFormArrayState, createFormControlState, createFormGroupState } from './state';
+import { cast, createFormArrayState, createFormControlState, createFormGroupState, isGroupState, isArrayState } from './state';
 
 describe('state', () => {
   const FORM_CONTROL_ID = 'test ID';
@@ -213,4 +213,46 @@ describe('state', () => {
       expect(initialState.controls).toEqual([]);
     });
   });
+
+  describe(isArrayState.name, () => {
+    it('should return true for array state', () => {
+      const INITIAL_STATE = createFormArrayState<string>(FORM_CONTROL_ID, ['abc']);
+      expect(isArrayState(INITIAL_STATE)).toBe(true);
+    });
+
+    it('should return false for group state', () => {
+      const INITIAL_STATE = createFormGroupState<any>(FORM_CONTROL_ID, { control: 'abc' });
+      expect(isArrayState(INITIAL_STATE)).toBe(false);
+    });
+
+    it('should return false for control state', () => {
+      const INITIAL_STATE = createFormControlState<string>(FORM_CONTROL_ID, 'abc');
+      expect(isArrayState(INITIAL_STATE)).toBe(false);
+    });
+
+    it('should return false for update object', () => {
+      expect(isArrayState({ controls: () => void 0 } as any)).toBe(false);
+    });
+  });
+
+  describe(isGroupState.name, () => {
+    it('should return true for group state', () => {
+      const INITIAL_STATE = createFormGroupState<any>(FORM_CONTROL_ID, { control: 'abc' });
+      expect(isGroupState(INITIAL_STATE)).toBe(true);
+    });
+
+    it('should return false for control state', () => {
+      const INITIAL_STATE = createFormControlState<string>(FORM_CONTROL_ID, 'abc');
+      expect(isGroupState(INITIAL_STATE)).toBe(false);
+    });
+
+    it('should return false for array state', () => {
+      const INITIAL_STATE = createFormArrayState<string>(FORM_CONTROL_ID, ['abc']);
+      expect(isGroupState(INITIAL_STATE)).toBe(false);
+    });
+
+    it('should return false for update object', () => {
+      expect(isGroupState({ controls: () => void 0 } as any)).toBe(false);
+    });
+  });
 });

src/state.ts

@@ -499,14 +499,16 @@ export interface FormArrayState<TValue> extends AbstractControlState<TValue[]> {
  * This function determines if a form state is an array state.
  */
 export function isArrayState(state: AbstractControlState<any>): state is FormArrayState<any> {
-  return state.hasOwnProperty('controls') && Array.isArray((state as any).controls);
+  const controls = (state as any).controls;
+  return state.hasOwnProperty('controls') && Array.isArray(controls) && typeof controls !== 'function';
 }
 
 /**
  * This function determines if a form state is a group state.
  */
 export function isGroupState(state: AbstractControlState<any>): state is FormGroupState<any> {
-  return state.hasOwnProperty('controls') && !Array.isArray((state as any).controls);
+  const controls = (state as any).controls;
+  return state.hasOwnProperty('controls') && !Array.isArray(controls) && typeof controls !== 'function';
 }
 
 /**

src/update-function/update-group.spec.ts

@@ -28,6 +28,11 @@ describe(updateGroup.name, () => {
     expect(resultState.controls.inner5).toBe(expected);
   });
 
+  it('should not change the state with empty update object', () => {
+    const resultState = updateGroup<FormGroupValue>({})(INITIAL_STATE);
+    expect(resultState).toBe(resultState);
+  });
+
   it('should apply the provided functions to control children uncurried', () => {
     const expected = { ...INITIAL_STATE.controls.inner, value: 'A' };
     const resultState = updateGroup<FormGroupValue>(
@@ -61,6 +66,11 @@ describe(updateGroup.name, () => {
     expect(resultState.controls.inner5).toBe(expected);
   });
 
+  it('should not change the state with empty update object uncurried', () => {
+    const resultState = updateGroup<FormGroupValue>(INITIAL_STATE, {});
+    expect(resultState).toBe(resultState);
+  });
+
   it('should apply multiple provided function objects one after another', () => {
     const updatedInner1 = { ...INITIAL_STATE.controls.inner, value: 'A' };
     const expectedInner1 = { ...INITIAL_STATE.controls.inner, value: 'B' };

src/update-function/update-group.ts

@@ -2,7 +2,7 @@ import { Action } from '@ngrx/store';
 
 import { formGroupReducer } from '../group/reducer';
 import { computeGroupState } from '../group/reducer/util';
-import { AbstractControlState, FormGroupControls, FormGroupState, KeyValue } from '../state';
+import { AbstractControlState, FormGroupControls, FormGroupState, KeyValue, isGroupState } from '../state';
 import { ProjectFn2 } from './util';
 
 export type StateUpdateFns<TValue extends KeyValue> =
@@ -108,8 +108,7 @@ export function updateGroup<TValue extends KeyValue>(
   stateOrFunction: FormGroupState<TValue> | StateUpdateFns<TValue>,
   ...updateFnsArr: Array<StateUpdateFns<TValue>>,
 ) {
-  const isUpdateFunctionObject = Object.keys(stateOrFunction).some(key => typeof (stateOrFunction as any)[key] === 'function');
-  if (!isUpdateFunctionObject) {
+  if (isGroupState(stateOrFunction as any)) {
     const [first, ...rest] = updateFnsArr;
     return updateGroup(first, ...rest)(stateOrFunction as any);
   }