fix(utils): each must handle falsy object (#605)

src/access-control.js

@@ -1,6 +1,7 @@
 import get from 'lodash/get';
 import clone from 'lodash/clone';
 import Roles from './roles';
+import utils from './utils/utils';
 
 // e.g.
 // access: {
@@ -110,7 +111,9 @@ export default class AccessControl {
 
   canAccess(operation, access, indexedRoles, fieldValues, isOwner) {
     const errors = [];
-    Object.keys(fieldValues).forEach((name) => {
+    // Note: we use `utils.each`, instead of `Object.keys(fieldValues)` as fieldValues can be
+    // undefined when called by mson-server
+    utils.each(fieldValues, (value, name) => {
       if (
         !this._canAccessField(operation, access, indexedRoles, name, isOwner)
       ) {

src/component/validator.js

@@ -2,6 +2,7 @@ import { cloneDeep } from '../utils/deep-clone';
 import { filter } from '../compiler/query';
 import PropFiller from '../compiler/prop-filler';
 import queryToProps from '../component/query-to-props';
+import utils from '../utils/utils';
 
 export default class Validator {
   constructor(props) {
@@ -15,7 +16,9 @@ export default class Validator {
 
   // Performs in place fill to prepare for query
   _fillWhere(where) {
-    Object.entries(where).forEach(([name, node]) => {
+    // Note: we use `utils.each`, instead of `Object.entries(where)` as where can be
+    // undefined when called by mson-server
+    utils.each(where, (node, name) => {
       // Leaf node?
       if (typeof node === 'string') {
         where[name] = this._fillProps(node);

src/utils/utils.js

@@ -178,15 +178,18 @@ export class Utils {
     }
   }
 
-  // Note: only use this if you need to exit the loop prematurely by having onItem() return false.
-  // Otherwise, just use Object.entries(), Object.keys(), or Object.values().
+  // Note: only use this if you need to exit the loop prematurely by having onItem() return false;
+  // or if obj may be falsy. Otherwise, just use Object.entries(), Object.keys(), or
+  // Object.values().
   each(obj, onItem) {
-    const entries = Object.entries(obj);
-    for (let i = 0; i < entries.length; i++) {
-      const [key, value] = entries[i];
-      const again = onItem(value, key);
-      if (again === false) {
-        break;
+    if (obj !== undefined && obj !== null) {
+      const entries = Object.entries(obj);
+      for (let i = 0; i < entries.length; i++) {
+        const [key, value] = entries[i];
+        const again = onItem(value, key);
+        if (again === false) {
+          break;
+        }
       }
     }
   }

src/utils/utils.test.js

@@ -116,3 +116,13 @@ it('should convert to RegExp', () => {
   expect(utils.isRegExpString('/[1-9]AB/')).toEqual(true);
   expect(utils.isRegExpString('(')).toEqual(false);
 });
+
+it('each should handle falsy values', () => {
+  const onItem = jest.fn();
+
+  utils.each(null, onItem);
+  expect(onItem).toHaveBeenCalledTimes(0);
+
+  utils.each(undefined, onItem);
+  expect(onItem).toHaveBeenCalledTimes(0);
+});