Improve data model & fix tests

backend/src/Model/spec/TreeNode.spec.ts

@@ -1,36 +1,44 @@
-import { Edge, Tree, TreeNode, TreeNodeFactory } from '../'
-import { expect } from 'chai';
-import 'mocha';
-
+import { TreeNodeFactory } from  '../'
 import './TreeNode.findNode'
+import { expect } from 'chai'
+import 'mocha'
 
 describe('TreeNode', () => {
+  it('firstNode should retrieve first node', () => {
+    const topics = 'foo/bar'.split('/')
+    const leaf = TreeNodeFactory.fromEdgesAndValue(topics, 3)
+
+    expect(leaf.firstNode().edges['foo']).to.not.eq(undefined)
+  })
+
   it('updateWithNode should update value', () => {
     const topics = 'foo/bar'.split('/')
     const leaf = TreeNodeFactory.fromEdgesAndValue(topics, 3)
-    expect(leaf.value).to.eq(3)
+    expect(leaf.message && leaf.message.value).to.eq(3)
     const updateLeave = TreeNodeFactory.fromEdgesAndValue(topics, 5)
-    leaf.firstNode().updateWithNode(updateLeave.firstNode())
 
-    expect(leaf.firstNode().sourceEdge.name).to.eq(updateLeave.firstNode().sourceEdge.name)
-    expect(leaf.value).to.eq(5)
+    let root = leaf.firstNode()
+    root.updateWithNode(updateLeave.firstNode())
+
+    expect(root.sourceEdge).to.eq(undefined)
+    expect(leaf.message && leaf.message.value).to.eq(5)
   })
 
   it('updateWithNode should update intermediate nodes', () => {
     const topics1 = 'foo/bar/baz'.split('/')
     const leaf = TreeNodeFactory.fromEdgesAndValue(topics1, 3)
-    expect(leaf.value).to.eq(3)
+    expect(leaf.message && leaf.message.value).to.eq(3)
 
     const topics2 = 'foo/bar'.split('/')
     const updateLeave = TreeNodeFactory.fromEdgesAndValue(topics2, 5)
     leaf.firstNode().updateWithNode(updateLeave.firstNode())
 
     let barNode = leaf.firstNode().findNode('foo/bar')
-    expect(barNode && barNode.sourceEdge.name).to.eq('bar')
-    expect(barNode && barNode.value).to.eq(5)
+    expect(barNode && barNode.sourceEdge && barNode.sourceEdge.name).to.eq('bar')
+    expect(barNode && barNode.message && barNode.message.value).to.eq(5)
 
-    expect(leaf.sourceEdge.name).to.eq('baz')
-    expect(leaf.value).to.eq(3)
+    expect(leaf.sourceEdge && leaf.sourceEdge.name).to.eq('baz')
+    expect(leaf.message && leaf.message.value).to.eq(3)
   })
 
   it('updateWithNode should add nodes to the tree', () => {