chore(toolkit-lib): test cases for notices cache (#548)

Test cases for #545

---
By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache-2.0 license

Author: mrgrain

packages/@aws-cdk/toolkit-lib/test/api/notices/cached-data-source.test.ts

@@ -0,0 +1,77 @@
+import * as os from 'os';
+import * as path from 'path';
+import * as fs from 'fs-extra';
+import { asIoHelper } from '../../../lib/api/io/private';
+import { CachedDataSource } from '../../../lib/api/notices/cached-data-source';
+import { TestIoHost } from '../../_helpers';
+
+describe('CachedDataSource', () => {
+  const ioHost = new TestIoHost('trace');
+  const ioHelper = asIoHelper(ioHost, 'notices' as any);
+  let tempDir: string;
+  let cacheFilePath: string;
+
+  beforeEach(() => {
+    tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'cdk-test-'));
+    cacheFilePath = path.join(tempDir, 'nonexistent-dir', 'cache.json');
+
+    // Just to be sure, remove directory if it exists
+    const dirPath = path.dirname(cacheFilePath);
+    if (fs.existsSync(dirPath)) {
+      fs.rmdirSync(dirPath, { recursive: true });
+    }
+  });
+
+  afterEach(() => {
+    // Clean up temp directory
+    fs.rmdirSync(tempDir, { recursive: true });
+  });
+
+  test('ensures directory exists when saving cache file', async () => {
+    // GIVEN
+    const mockDataSource = {
+      fetch: jest.fn().mockResolvedValue([{ title: 'Test Notice' }]),
+    };
+    const dataSource = new CachedDataSource(ioHelper, cacheFilePath, mockDataSource);
+
+    // WHEN
+    await dataSource.fetch();
+
+    // THEN
+    // Directory should have been created
+    expect(fs.existsSync(path.dirname(cacheFilePath))).toBe(true);
+    // Cache file should exist
+    expect(fs.existsSync(cacheFilePath)).toBe(true);
+    // Cache file should contain the fetched data
+    const cachedContent = fs.readJSONSync(cacheFilePath);
+    expect(cachedContent).toHaveProperty('notices');
+    expect(cachedContent.notices).toEqual([{ title: 'Test Notice' }]);
+  });
+
+  test('handles errors when ensuring directory exists', async () => {
+    // GIVEN
+    const mockDataSource = {
+      fetch: jest.fn().mockResolvedValue([{ title: 'Test Notice' }]),
+    };
+
+    // Mock fs.ensureFile to throw an error
+    jest.spyOn(fs, 'ensureFile').mockImplementationOnce(() => {
+      throw new Error('Failed to create directory');
+    });
+
+    const dataSource = new CachedDataSource(ioHelper, cacheFilePath, mockDataSource);
+
+    // WHEN
+    await dataSource.fetch();
+
+    // THEN
+    // Should have logged the error
+    ioHost.expectMessage({
+      level: 'debug',
+      containing: 'Failed to store notices in the cache: Error: Failed to create directory',
+    });
+
+    // Should still return data from the source
+    expect(mockDataSource.fetch).toHaveBeenCalled();
+  });
+});