🧪 Add missing tests for loadSession parsing failure in src/api.ts (#20)

- Mocked fs.existsSync to return true
- Mocked fs.readFileSync to return an invalid JSON string
- Tested that loadSession throws a JSON parse error (SyntaxError)
- Verified that console.error is called during the failure
- Handled mock restoration correctly using spyOn to avoid interfering with other tests

Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>
Co-authored-by: sunnylqm <615282+sunnylqm@users.noreply.github.com>

Author: sunnylqm

bun.lock

@@ -0,0 +1,31 @@
+import { describe, expect, test, mock, afterEach, beforeEach, spyOn } from 'bun:test';
+import fs from 'fs';
+import { loadSession } from '../src/api';
+
+describe('api.ts loadSession', () => {
+  let originalConsoleError: any;
+  let existsSyncSpy: any;
+  let readFileSyncSpy: any;
+
+  beforeEach(() => {
+    originalConsoleError = console.error;
+    console.error = mock(() => {});
+
+    // Use spyOn to mock specific fs methods
+    existsSyncSpy = spyOn(fs, 'existsSync').mockReturnValue(true);
+    readFileSyncSpy = spyOn(fs, 'readFileSync').mockReturnValue('{ "invalid": json ');
+  });
+
+  afterEach(() => {
+    console.error = originalConsoleError;
+    existsSyncSpy.mockRestore();
+    readFileSyncSpy.mockRestore();
+  });
+
+  test('loadSession throws error on JSON parse failure', async () => {
+    // Assert that the Promise rejects with a SyntaxError (JSON parse error)
+    await expect(loadSession()).rejects.toThrow(SyntaxError);
+    // Verify that console.error was called
+    expect(console.error).toHaveBeenCalled();
+  });
+});