chore: refactoring tag coloring

tests/renderer/utils/tagColors.test.ts

@@ -0,0 +1,49 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { buildTagColorMap, loadTagColorMap } from '../../../src/renderer/utils/tagColors';
+
+describe('tagColors utils', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it('buildTagColorMap includes only tags with colors', () => {
+    const map = buildTagColorMap([
+      { id: '1', name: 'alpha', color: '#111111' },
+      { id: '2', name: 'beta' },
+      { id: '3', name: 'gamma', color: '#333333' },
+      { id: '4', name: 'delta', color: null },
+    ]);
+
+    expect(map.get('alpha')).toBe('#111111');
+    expect(map.get('gamma')).toBe('#333333');
+    expect(map.has('beta')).toBe(false);
+    expect(map.has('delta')).toBe(false);
+  });
+
+  it('loadTagColorMap resolves colors from electron tags api', async () => {
+    (window as any).electronAPI = {
+      ...(window as any).electronAPI,
+      tags: {
+        getAll: vi.fn().mockResolvedValue([
+          { id: '1', name: 'blue', color: '#0000ff' },
+          { id: '2', name: 'red', color: '#ff0000' },
+        ]),
+      },
+    };
+
+    const map = await loadTagColorMap();
+
+    expect(map.get('blue')).toBe('#0000ff');
+    expect(map.get('red')).toBe('#ff0000');
+  });
+
+  it('loadTagColorMap returns empty map when api is unavailable', async () => {
+    (window as any).electronAPI = {
+      ...(window as any).electronAPI,
+      tags: undefined,
+    };
+
+    const map = await loadTagColorMap();
+    expect(map.size).toBe(0);
+  });
+});