1 files changed, 110 insertions, 0 deletions
diff --git a/packages/cli/src/services/CommandService.test.ts b/packages/cli/src/services/CommandService.test.ts
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+++ b/packages/cli/src/services/CommandService.test.ts
@@ -0,0 +1,110 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { vi, describe, it, expect, beforeEach } from 'vitest';
+import { CommandService } from './CommandService.js';
+import { type SlashCommand } from '../ui/commands/types.js';
+import { memoryCommand } from '../ui/commands/memoryCommand.js';
+import { helpCommand } from '../ui/commands/helpCommand.js';
+import { clearCommand } from '../ui/commands/clearCommand.js';
+
+// Mock the command modules to isolate the service from the command implementations.
+vi.mock('../ui/commands/memoryCommand.js', () => ({
+  memoryCommand: { name: 'memory', description: 'Mock Memory' },
+}));
+vi.mock('../ui/commands/helpCommand.js', () => ({
+  helpCommand: { name: 'help', description: 'Mock Help' },
+}));
+vi.mock('../ui/commands/clearCommand.js', () => ({
+  clearCommand: { name: 'clear', description: 'Mock Clear' },
+}));
+
+describe('CommandService', () => {
+  describe('when using default production loader', () => {
+    let commandService: CommandService;
+
+    beforeEach(() => {
+      commandService = new CommandService();
+    });
+
+    it('should initialize with an empty command tree', () => {
+      const tree = commandService.getCommands();
+      expect(tree).toBeInstanceOf(Array);
+      expect(tree.length).toBe(0);
+    });
+
+    describe('loadCommands', () => {
+      it('should load the built-in commands into the command tree', async () => {
+        // Pre-condition check
+        expect(commandService.getCommands().length).toBe(0);
+
+        // Action
+        await commandService.loadCommands();
+        const tree = commandService.getCommands();
+
+        // Post-condition assertions
+        expect(tree.length).toBe(3);
+
+        const commandNames = tree.map((cmd) => cmd.name);
+        expect(commandNames).toContain('memory');
+        expect(commandNames).toContain('help');
+        expect(commandNames).toContain('clear');
+      });
+
+      it('should overwrite any existing commands when called again', async () => {
+        // Load once
+        await commandService.loadCommands();
+        expect(commandService.getCommands().length).toBe(3);
+
+        // Load again
+        await commandService.loadCommands();
+        const tree = commandService.getCommands();
+
+        // Should not append, but overwrite
+        expect(tree.length).toBe(3);
+      });
+    });
+
+    describe('getCommandTree', () => {
+      it('should return the current command tree', async () => {
+        const initialTree = commandService.getCommands();
+        expect(initialTree).toEqual([]);
+
+        await commandService.loadCommands();
+
+        const loadedTree = commandService.getCommands();
+        expect(loadedTree.length).toBe(3);
+        expect(loadedTree).toEqual([clearCommand, helpCommand, memoryCommand]);
+      });
+    });
+  });
+
+  describe('when initialized with an injected loader function', () => {
+    it('should use the provided loader instead of the built-in one', async () => {
+      // Arrange: Create a set of mock commands.
+      const mockCommands: SlashCommand[] = [
+        { name: 'injected-test-1', description: 'injected 1' },
+        { name: 'injected-test-2', description: 'injected 2' },
+      ];
+
+      // Arrange: Create a mock loader FUNCTION that resolves with our mock commands.
+      const mockLoader = vi.fn().mockResolvedValue(mockCommands);
+
+      // Act: Instantiate the service WITH the injected loader function.
+      const commandService = new CommandService(mockLoader);
+      await commandService.loadCommands();
+      const tree = commandService.getCommands();
+
+      // Assert: The tree should contain ONLY our injected commands.
+      expect(mockLoader).toHaveBeenCalled(); // Verify our mock loader was actually called.
+      expect(tree.length).toBe(2);
+      expect(tree).toEqual(mockCommands);
+
+      const commandNames = tree.map((cmd) => cmd.name);
+      expect(commandNames).not.toContain('memory'); // Verify it didn't load production commands.
+    });
+  });
+});