test: add cases for traverseFiber

Author: Asuka109

packages/bippy/src/core.test.tsx

@@ -0,0 +1,49 @@
+import type React from 'react';
+import { render, type RenderOptions } from '@testing-library/react';
+import { describe, expect, it, vi } from 'vitest';
+import { instrument, traverseFiber } from './core.js';
+import type { FiberRoot } from './types.js';
+
+describe('traverseFiber', () => {
+  const onCommitFiberRoot = vi.fn();
+  instrument({ onCommitFiberRoot });
+
+  const renderWithFiber = (ui: React.ReactNode, options?: RenderOptions) => {
+    const result = render(ui, options);
+    const fiber: FiberRoot = onCommitFiberRoot.mock.lastCall?.[1];
+    return { ...result, fiber };
+  };
+
+  const { fiber } = renderWithFiber(
+    <div key="root">
+      <div key="a">
+        <div key="a1" />
+        <div key="a2" />
+      </div>
+      <div key="b" />
+      <div key="c" />
+      <div key="d">
+        <div key="d1">
+          <div key="d11" />
+        </div>
+      </div>
+    </div>,
+  );
+
+  it('should traverse a fiber', () => {
+    const handler = vi.fn();
+    traverseFiber(fiber.current, fiber => handler(fiber.key));
+    const keys = handler.mock.calls.map(call => call[0]).slice(1);
+    const expected = ['root', 'a', 'a1', 'a2', 'b', 'c', 'd', 'd1', 'd11'];
+    expect(keys).toEqual(expected);
+  });
+
+  it('should traverse a fiber in reverse', () => {
+    const handler = vi.fn();
+    const d11 = traverseFiber(fiber.current, fiber => fiber.key === 'd11');
+    expect(d11?.key).toBe('d11');
+    traverseFiber(d11, fiber => handler(fiber.key), true);
+    const keys = handler.mock.calls.map(call => call[0]).slice(0, -1);
+    expect(keys).toEqual(['d11', 'd1', 'd', 'root']);
+  });
+});

setup-test.ts

@@ -0,0 +1 @@
+import './src/rdt-hook';

tsconfig.json

@@ -1,6 +1,6 @@
 {
 	"compilerOptions": {
-		"jsx": "react",
+		"jsx": "react-jsx",
 		"module": "NodeNext",
 		"esModuleInterop": true,
 		"strictNullChecks": true,