Fixes nested computed properties issue

src/__tests__/issue217.test.js

@@ -0,0 +1,33 @@
+import { action, computed, createStore } from '../index';
+
+test('issue217', () => {
+  const model = {
+    items: {},
+
+    nested: {
+      numbers: [1, 2, 3],
+      filteredNumbers: computed(state => {
+        return state.numbers.filter(number => number > 1);
+      }),
+    },
+
+    // selectors
+    list: computed(items => Object.values(items), [state => state.items]),
+
+    // actions
+    fetched: action((state, payload) => {
+      state.items = payload.reduce((acc, todo) => {
+        acc[todo.id] = todo;
+        return acc;
+      }, {});
+    }),
+  };
+
+  const store = createStore(model);
+
+  // act
+  store.getActions().fetched([{ id: 1, text: 'foo' }]);
+
+  // assert
+  expect(store.getState().nested.filteredNumbers).toEqual([2, 3]);
+});

src/create-store-internals.js

@@ -474,7 +474,9 @@ export default function createStoreInternals({
         if (computedPropertyCreators) {
           const updatedCurrent = get(path, updatedState);
           Object.keys(computedPropertyCreators).forEach(key => {
-            computedPropertyCreators[key](updatedCurrent);
+            if (typeof computedPropertyCreators[key] === 'function') {
+              computedPropertyCreators[key](updatedCurrent);
+            }
           });
         }
       }