feat: post-order traversal

Signed-off-by: Andres Correa Casablanca <castarco@coderspirit.xyz>

Author: castarco

.github/workflows/tests.yml

@@ -41,4 +41,4 @@ jobs:
     - name: Build Library
       run: pnpm build
     - name: Run Tests
-      run: pnpm test
+      run: pnpm test:coverage

src/BeautifulTree.tsx

@@ -1,4 +1,4 @@
-import type { Tree } from './core'
+import type { Tree } from './layouts'
 
 export interface BeautifulTreeProps {
 	readonly id: string

src/core.ts renamed to src/layouts.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'vitest'
-import { computeLeftShiftLayout } from '../core'
+import { computeLeftShiftLayout } from '../layouts'
 
 describe('computeLeftShiftLayout', () => {
 	it('sets x=0,y=0 for a single-node tree, and data is preserved', () => {

src/tests/core.test.ts renamed to src/tests/layouts.test.ts

@@ -0,0 +1,54 @@
+import { describe, expect, it } from 'vitest'
+import { postOrderIterator } from '../traversal'
+
+describe('postOrderIterator', () => {
+	const testTree = {
+		data: { v: 42 },
+		children: [
+			{
+				edgeData: {},
+				node: {
+					data: { v: 43 },
+					children: [
+						{
+							edgeData: {},
+							node: { data: { v: 45 } },
+						},
+					],
+				},
+			},
+			{
+				edgeData: {},
+				node: {
+					data: { v: 44 },
+					children: [
+						{
+							edgeData: {},
+							node: { data: { v: 46 } },
+						},
+						{
+							edgeData: {},
+							node: { data: { v: 47 } },
+						},
+					],
+				},
+			},
+		],
+	}
+
+	it('traverses tree in post-order', () => {
+		const result = postOrderIterator(testTree)
+
+		console.log('result:')
+		const expandedResult = [...result]
+
+		expect(expandedResult).toEqual([
+			{ v: 45 },
+			{ v: 43 },
+			{ v: 46 },
+			{ v: 47 },
+			{ v: 44 },
+			{ v: 42 },
+		])
+	})
+})

src/tests/traversal.test.ts

@@ -0,0 +1,10 @@
+import type { Tree, TreeWithLayout } from './layouts'
+
+export function* postOrderIterator<T extends Tree | TreeWithLayout = Tree>(
+	v: Readonly<T>,
+): Generator<T['data'], void> {
+	for (const child of v.children ?? []) {
+		yield* postOrderIterator<T>(child.node as T)
+	}
+	yield v.data
+}