feat(store): add immutability and serializability runtime checks (#1613)

Closes #857

Author: timdeschryver

modules/router-store/spec/integration.spec.ts

@@ -253,7 +253,13 @@ describe('integration spec', () => {
       } else {
         const nextState = routerReducer(state, action);
         if (nextState && nextState.state) {
-          nextState.state.root = <any>{};
+          return {
+            ...nextState,
+            state: {
+              ...nextState.state,
+              root: {} as any,
+            },
+          };
         }
         return nextState;
       }
@@ -383,7 +389,13 @@ describe('integration spec', () => {
       } else {
         const nextState = routerReducer(state, action);
         if (nextState && nextState.state) {
-          nextState.state.root = <any>{};
+          return {
+            ...nextState,
+            state: {
+              ...nextState.state,
+              root: {} as any,
+            },
+          };
         }
         return nextState;
       }

modules/store/spec/meta-reducers/action_serialization_reducer.spec.ts

@@ -0,0 +1,23 @@
+import { actionSerializationCheckMetaReducer } from '../../src/meta-reducers';
+
+describe('actionSerializationCheckMetaReducer:', () => {
+  describe('valid action:', () => {
+    it('should not throw', () => {
+      expect(() =>
+        invokeReducer({ type: 'valid', payload: { id: 47 } })
+      ).not.toThrow();
+    });
+  });
+
+  describe('invalid action:', () => {
+    it('should throw', () => {
+      expect(() =>
+        invokeReducer({ type: 'invalid', payload: { date: new Date() } })
+      ).toThrow();
+    });
+  });
+
+  function invokeReducer(action: any) {
+    actionSerializationCheckMetaReducer(() => {})(undefined, action);
+  }
+});

modules/store/spec/meta-reducers/immutability_reducer.spec.ts

@@ -0,0 +1,57 @@
+import { immutabilityCheckMetaReducer } from '../../src/meta-reducers';
+
+describe('immutabilityCheckMetaReducer:', () => {
+  describe('actions:', () => {
+    it('should not throw if left untouched', () => {
+      expect(() => invokeReducer((action: any) => action)).not.toThrow();
+    });
+
+    it('should throw when mutating an action', () => {
+      expect(() =>
+        invokeReducer((action: any) => {
+          action.foo = '123';
+        })
+      ).toThrow();
+      expect(() =>
+        invokeReducer((action: any) => {
+          action.numbers.push(4);
+        })
+      ).toThrow();
+    });
+
+    function invokeReducer(reduce: Function) {
+      immutabilityCheckMetaReducer((state, action) => {
+        reduce(action);
+        return state;
+      })({}, { type: 'invoke', numbers: [1, 2, 3] });
+    }
+  });
+
+  describe('state:', () => {
+    it('should not throw if left untouched', () => {
+      expect(() =>
+        invokeReducer((state: any) => ({ ...state, foo: 'bar' }))
+      ).not.toThrow();
+    });
+
+    it('should throw when mutating state', () => {
+      expect(() =>
+        invokeReducer((state: any) => {
+          state.foo = '123';
+        })
+      ).toThrow();
+      expect(() =>
+        invokeReducer((state: any) => {
+          state.numbers.push(4);
+        })
+      ).toThrow();
+    });
+
+    function invokeReducer(reduce: Function) {
+      immutabilityCheckMetaReducer((state, _action) => reduce(state))(
+        { numbers: [1, 2, 3] },
+        { type: 'invoke' }
+      );
+    }
+  });
+});

modules/store/spec/meta-reducers/state_serialization_reducer.spec.ts

@@ -0,0 +1,25 @@
+import { stateSerializationCheckMetaReducer } from '../../src/meta-reducers';
+
+describe('stateSerializationCheckMetaReducer:', () => {
+  describe('valid next state:', () => {
+    it('should not throw', () => {
+      expect(() =>
+        invokeReducer({
+          nested: { number: 1, null: null },
+        })
+      ).not.toThrow();
+    });
+  });
+
+  describe('invalid next state:', () => {
+    it('should throw', () => {
+      expect(() => invokeReducer({ nested: { class: new Date() } })).toThrow();
+    });
+  });
+
+  function invokeReducer(nextState?: any) {
+    stateSerializationCheckMetaReducer(() => nextState)(undefined, {
+      type: 'invokeReducer',
+    });
+  }
+});

modules/store/spec/meta-reducers/utils.spec.ts

@@ -0,0 +1,82 @@
+import {
+  getUnserializable,
+  throwIfUnserializable,
+} from '../../src/meta-reducers/utils';
+
+describe('getUnserializable:', () => {
+  describe('serializable value:', () => {
+    it('should not throw', () => {
+      expect(getUnserializable(1)).toBe(false);
+      expect(getUnserializable(true)).toBe(false);
+      expect(getUnserializable('string')).toBe(false);
+      expect(getUnserializable([1, 2, 3])).toBe(false);
+      expect(getUnserializable({})).toBe(false);
+      expect(
+        getUnserializable({
+          nested: { number: 1, undefined: undefined, null: null },
+        })
+      ).toBe(false);
+    });
+  });
+
+  describe('unserializable value:', () => {
+    it('should throw', () => {
+      class TestClass {}
+
+      expect(getUnserializable()).toEqual({ value: undefined, path: ['root'] });
+      expect(getUnserializable(null)).toEqual({ value: null, path: ['root'] });
+
+      const date = new Date();
+      expect(getUnserializable({ date })).toEqual({
+        value: date,
+        path: ['date'],
+      });
+      expect(getUnserializable({ set: new Set([]) })).toEqual({
+        value: new Set([]),
+        path: ['set'],
+      });
+      expect(getUnserializable({ map: new Map([]) })).toEqual({
+        value: new Map([]),
+        path: ['map'],
+      });
+      expect(getUnserializable({ class: new TestClass() })).toEqual({
+        value: new TestClass(),
+        path: ['class'],
+      });
+      expect(
+        getUnserializable({
+          nested: { valid: true, class: new TestClass(), alsoValid: '' },
+          valid: [3],
+        })
+      ).toEqual({ value: new TestClass(), path: ['nested', 'class'] });
+    });
+  });
+});
+
+describe('throwIfUnserializable', () => {
+  describe('serializable', () => {
+    it('should not throw an error', () => {
+      expect(() => throwIfUnserializable(false, 'state')).not.toThrow();
+    });
+  });
+
+  describe('unserializable', () => {
+    it('should throw an error', () => {
+      expect(() =>
+        throwIfUnserializable({ path: ['root'], value: undefined }, 'state')
+      ).toThrowError(`Detected unserializable state at "root"`);
+      expect(() =>
+        throwIfUnserializable({ path: ['date'], value: new Date() }, 'action')
+      ).toThrowError(`Detected unserializable action at "date"`);
+      expect(() =>
+        throwIfUnserializable(
+          {
+            path: ['one', 'two', 'three'],
+            value: new Date(),
+          },
+          'state'
+        )
+      ).toThrowError(`Detected unserializable state at "one.two.three"`);
+    });
+  });
+});