feat: Multi-Directory Workspace Support (part1: add --include-directories option) (#4605)

Co-authored-by: Allen Hutchison <adh@google.com>

packages/core/src/test-utils/mockWorkspaceContext.ts

@@ -0,0 +1,33 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { vi } from 'vitest';
+import { WorkspaceContext } from '../utils/workspaceContext.js';
+
+/**
+ * Creates a mock WorkspaceContext for testing
+ * @param rootDir The root directory to use for the mock
+ * @param additionalDirs Optional additional directories to include in the workspace
+ * @returns A mock WorkspaceContext instance
+ */
+export function createMockWorkspaceContext(
+  rootDir: string,
+  additionalDirs: string[] = [],
+): WorkspaceContext {
+  const allDirs = [rootDir, ...additionalDirs];
+
+  const mockWorkspaceContext = {
+    addDirectory: vi.fn(),
+    getDirectories: vi.fn().mockReturnValue(allDirs),
+    isPathWithinWorkspace: vi
+      .fn()
+      .mockImplementation((path: string) =>
+        allDirs.some((dir) => path.startsWith(dir)),
+      ),
+  } as unknown as WorkspaceContext;
+
+  return mockWorkspaceContext;
+}