gemini-cli/packages/test-utils/GEMINI.md

Gemini CLI Test Utils (@google/gemini-cli-test-utils)

Shared test utilities used across the monorepo. This is a private package — not published to npm.

Key Modules

• src/test-rig.ts: The primary test rig for spinning up end-to-end CLI sessions with mock responses.
• src/file-system-test-helpers.ts: Helpers for creating temporary file system fixtures.
• src/mock-utils.ts: Common mock utilities.
• src/test-mcp-server.ts: Helper for building test MCP servers for tests.
• src/test-mcp-server-template.mjs: Generic template script for running isolated MCP processes.

Test MCP Servers

The TestRig provides a fully isolated, compliant way to test tool triggers and workflows using local test MCP servers. This isolates your tests from live API endpoints and rate-limiting.

Usage

1. Programmatic Builder:

   import { TestMcpServerBuilder } from '@google/gemini-cli-test-utils';
   
   const builder = new TestMcpServerBuilder('weather-server').addTool(
     'get_weather',
     'Get weather',
     'It is rainy',
   );
   
   rig.addTestMcpServer('weather-server', builder.build());
   

2. Predefined configurations via JSON: Place a configuration file in packages/test-utils/assets/test-servers/google-workspace.json and load it by title:

   rig.addTestMcpServer('workspace-server', 'google-workspace');
   

   JSON Format Structure (TestMcpConfig):

   {
     "name": "string (Fallback server name)",
     "tools": [
       {
         "name": "string (Tool execution name)",
         "description": "string (Helpful summary for router)",
         "inputSchema": {
           "type": "object",
           "properties": { ... }
         },
         "response": "string | object (The forced reply payload)"
       }
     ]
   }
   

Usage

Import from @google/gemini-cli-test-utils in test files across the monorepo.