fix: added unit test and switched to unshift

src/tree/__tests__/render.spec.js

@@ -0,0 +1,99 @@
+import { hierarchy } from 'd3';
+import { filterTree } from '../render';
+
+const nodes = {
+  id: '1',
+  elemNo: 1,
+  children: [
+    {
+      id: '2',
+      elemNo: 2,
+      children: [
+        {
+          id: '3',
+          elemNo: 3,
+          parent: {
+            data: {
+              id: '2',
+            },
+          },
+          children: [
+            {
+              id: '5',
+              elemNo: 798,
+              parent: {
+                id: '3',
+              },
+            },
+          ],
+        },
+      ],
+    },
+    {
+      id: '4',
+      elemNo: 88,
+      children: [],
+    },
+  ],
+};
+
+describe('render', () => {
+  describe('filterTree', () => {
+    let topId;
+    let isExpanded;
+    let expandedChildren;
+    let nodeTree;
+    beforeEach(() => {
+      topId = '1';
+      isExpanded = false;
+      expandedChildren = [];
+      nodeTree = hierarchy(nodes);
+    });
+
+    it('should return the only top node', () => {
+      const result = filterTree({ topId, isExpanded, expandedChildren }, nodeTree);
+      expect(result.length).to.equal(1);
+      expect(result[0].data.id).to.equal('1');
+    });
+
+    it('should return only the top node when topId not found', () => {
+      topId = 'someInsaneId';
+      const result = filterTree({ topId, isExpanded, expandedChildren }, nodeTree);
+      expect(result.length).to.equal(1);
+      expect(result[0].data.id).to.equal('1');
+    });
+
+    it('should return the top node and children', () => {
+      isExpanded = true;
+      const result = filterTree({ topId, isExpanded, expandedChildren }, nodeTree);
+      expect(result.length).to.equal(3);
+      expect(result.map(node => node.data.id)).to.deep.equal(['1', '2', '4']);
+    });
+
+    it('should return the top node and children and grandchildren of expanded', () => {
+      isExpanded = true;
+      expandedChildren = ['2'];
+      const result = filterTree({ topId, isExpanded, expandedChildren }, nodeTree);
+      expect(result.length).to.equal(4);
+      expect(result.map(node => node.data.id)).to.deep.equal(['1', '2', '3', '4']);
+    });
+
+    it('should return the top node and children with navigation mode free', () => {
+      nodeTree.data.navigationMode = 'free';
+      isExpanded = true;
+      topId = '2';
+      const result = filterTree({ topId, isExpanded, expandedChildren }, nodeTree);
+      expect(result.length).to.equal(4);
+      expect(result.map(node => node.data.id)).to.deep.equal(['1', '2', '4', '3']);
+    });
+
+    it('should return the top node and parents children with navigation mode free', () => {
+      nodeTree.data.navigationMode = 'free';
+      isExpanded = true;
+      topId = '5';
+      const result = filterTree({ topId, isExpanded, expandedChildren }, nodeTree);
+      expect(result.length).to.equal(5);
+      expect(result.map(node => node.data.id)).to.deep.equal(['1', '2', '4', '3', '5']);
+    });
+  });
+});

src/tree/render.js

@@ -4,7 +4,7 @@ import box from './box';
 import createPaths from './path';
 import transform from './transform';
 
-const filterTree = ({ topId, isExpanded, expandedChildren }, nodeTree) => {
+export const filterTree = ({ topId, isExpanded, expandedChildren }, nodeTree) => {
   const topNode = nodeTree.descendants().find(node => node.data.id === topId) || nodeTree;
   const subTree = [];
   if (isExpanded && topNode.children) {
@@ -22,13 +22,13 @@ const filterTree = ({ topId, isExpanded, expandedChildren }, nodeTree) => {
   if (nodeTree.data.navigationMode === 'free' && topNode.parent) {
     const ancestors = topNode.parent.ancestors();
     ancestors.forEach(ancestor => {
-      subTree.push(...ancestor.children);
+      subTree.unshift(...ancestor.children);
       if (!ancestor.parent) {
-        subTree.push(ancestor);
+        subTree.unshift(ancestor);
       }
     });
   } else {
-    subTree.push(topNode); // self
+    subTree.unshift(topNode); // self
   }
   return subTree;
 };