Make component throw an error when nodes have duplicate values

Addresses #211.

Author: jakezatecky

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### New Features
 
 * [#182]: Add `direction` property to support RTL languages
+* [#211]: Throw an error when nodes have duplicate values
 
 ## [v1.6.0](https://github.com/jakezatecky/react-checkbox-tree/compare/v1.5.0...v1.6.0) (2019-12-11)
 

src/js/CheckboxTree.js

@@ -117,6 +117,7 @@ class CheckboxTree extends React.Component {
 
         // Since flattening nodes is an expensive task, only update when there is a node change
         if (!isEqual(prevProps.nodes, nodes) || prevProps.disabled !== disabled) {
+            model.reset();
             model.flattenNodes(nodes);
         }
 

src/js/CheckboxTreeError.js

@@ -0,0 +1,9 @@
+function CheckboxTreeError(message) {
+    this.message = message;
+    this.stack = Error().stack;
+}
+
+CheckboxTreeError.prototype = Object.create(Error.prototype);
+CheckboxTreeError.prototype.name = 'CheckboxTreeError';
+
+export default CheckboxTreeError;

src/js/NodeModel.js

@@ -1,3 +1,4 @@
+import CheckboxTreeError from './CheckboxTreeError';
 import constants from './constants';
 
 const { CheckModel } = constants;
@@ -28,6 +29,10 @@ class NodeModel {
         return this.flatNodes[value];
     }
 
+    reset() {
+        this.flatNodes = {};
+    }
+
     flattenNodes(nodes, parent = {}, depth = 0) {
         if (!Array.isArray(nodes) || nodes.length === 0) {
             return;
@@ -39,6 +44,13 @@ class NodeModel {
         nodes.forEach((node, index) => {
             const isParent = this.nodeHasChildren(node);
 
+            // Protect against duplicate node values
+            if (this.flatNodes[node.value] !== undefined) {
+                throw new CheckboxTreeError(
+                    `Duplicate value '${node.value}' detected. All node values must be unique.`,
+                );
+            }
+
             this.flatNodes[node.value] = {
                 label: node.label,
                 value: node.value,

test/CheckboxTree.js

@@ -3,6 +3,7 @@ import { shallow, mount } from 'enzyme';
 import { assert } from 'chai';
 
 import CheckboxTree from '../src/js/CheckboxTree';
+import CheckboxTreeError from '../src/js/CheckboxTreeError';
 import TreeNode from '../src/js/TreeNode';
 
 describe('<CheckboxTree />', () => {
@@ -384,6 +385,34 @@ describe('<CheckboxTree />', () => {
             assert.equal(true, wrapper.find(TreeNode).prop('isParent'));
             assert.equal(false, wrapper.find(TreeNode).prop('isLeaf'));
         });
+
+        it('should throw an error when duplicate values are used', () => {
+            let errorMessage = null;
+
+            try {
+                shallow(
+                    <CheckboxTree
+                        nodes={[
+                            {
+                                value: 'jupiter',
+                                label: 'Jupiter',
+                                children: [
+                                    { value: 'jupiter', label: 'Jupiter' },
+                                ],
+                            },
+                        ]}
+                    />,
+                );
+            } catch (e) {
+                if (e instanceof CheckboxTreeError) {
+                    errorMessage = e.message;
+                } else {
+                    throw e;
+                }
+            }
+
+            assert.equal("Duplicate value 'jupiter' detected. All node values must be unique.", errorMessage);
+        });
     });
 
     describe('noCascade', () => {