Upgrade integration tests to use Vitest (#6021)

integration-tests/mcp_server_cyclic_schema.test.ts

@@ -0,0 +1,194 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * This test verifies we can match maximum schema depth errors from Gemini
+ * and then detect and warn about the potential tools that caused the error.
+ */
+
+import { describe, it, beforeAll, expect } from 'vitest';
+import { TestRig } from './test-helper.js';
+import { join } from 'path';
+import { writeFileSync } from 'fs';
+
+// Create a minimal MCP server that doesn't require external dependencies
+// This implements the MCP protocol directly using Node.js built-ins
+const serverScript = `#!/usr/bin/env node
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+const readline = require('readline');
+const fs = require('fs');
+
+// Debug logging to stderr (only when MCP_DEBUG or VERBOSE is set)
+const debugEnabled = process.env.MCP_DEBUG === 'true' || process.env.VERBOSE === 'true';
+function debug(msg) {
+  if (debugEnabled) {
+    fs.writeSync(2, \`[MCP-DEBUG] \${msg}\\n\`);
+  }
+}
+
+debug('MCP server starting...');
+
+// Simple JSON-RPC implementation for MCP
+class SimpleJSONRPC {
+  constructor() {
+    this.handlers = new Map();
+    this.rl = readline.createInterface({
+      input: process.stdin,
+      output: process.stdout,
+      terminal: false
+    });
+
+    this.rl.on('line', (line) => {
+      debug(\`Received line: \${line}\`);
+      try {
+        const message = JSON.parse(line);
+        debug(\`Parsed message: \${JSON.stringify(message)}\`);
+        this.handleMessage(message);
+      } catch (e) {
+        debug(\`Parse error: \${e.message}\`);
+      }
+    });
+  }
+
+  send(message) {
+    const msgStr = JSON.stringify(message);
+    debug(\`Sending message: \${msgStr}\`);
+    process.stdout.write(msgStr + '\\n');
+  }
+
+  async handleMessage(message) {
+    if (message.method && this.handlers.has(message.method)) {
+      try {
+        const result = await this.handlers.get(message.method)(message.params || {});
+        if (message.id !== undefined) {
+          this.send({
+            jsonrpc: '2.0',
+            id: message.id,
+            result
+          });
+        }
+      } catch (error) {
+        if (message.id !== undefined) {
+          this.send({
+            jsonrpc: '2.0',
+            id: message.id,
+            error: {
+              code: -32603,
+              message: error.message
+            }
+          });
+        }
+      }
+    } else if (message.id !== undefined) {
+      this.send({
+        jsonrpc: '2.0',
+        id: message.id,
+        error: {
+          code: -32601,
+          message: 'Method not found'
+        }
+      });
+    }
+  }
+
+  on(method, handler) {
+    this.handlers.set(method, handler);
+  }
+}
+
+// Create MCP server
+const rpc = new SimpleJSONRPC();
+
+// Handle initialize
+rpc.on('initialize', async (params) => {
+  debug('Handling initialize request');
+  return {
+    protocolVersion: '2024-11-05',
+    capabilities: {
+      tools: {}
+    },
+    serverInfo: {
+      name: 'cyclic-schema-server',
+      version: '1.0.0'
+    }
+  };
+});
+
+// Handle tools/list
+rpc.on('tools/list', async () => {
+  debug('Handling tools/list request');
+  return {
+    tools: [{
+      name: 'tool_with_cyclic_schema',
+      inputSchema: {
+        type: 'object',
+        properties: {
+          data: {
+            type: 'array',
+            items: {
+              type: 'object',
+              properties: {
+                child: { $ref: '#/properties/data/items' },
+              },
+            },
+          },
+        },
+      }
+    }]
+  };
+});
+
+// Send initialization notification
+rpc.send({
+  jsonrpc: '2.0',
+  method: 'initialized'
+});
+`;
+
+describe('mcp server with cyclic tool schema is detected', () => {
+  const rig = new TestRig();
+
+  beforeAll(async () => {
+    // Setup test directory with MCP server configuration
+    await rig.setup('cyclic-schema-mcp-server', {
+      settings: {
+        mcpServers: {
+          'cyclic-schema-server': {
+            command: 'node',
+            args: ['mcp-server.cjs'],
+          },
+        },
+      },
+    });
+
+    // Create server script in the test directory
+    const testServerPath = join(rig.testDir!, 'mcp-server.cjs');
+    writeFileSync(testServerPath, serverScript);
+
+    // Make the script executable (though running with 'node' should work anyway)
+    if (process.platform !== 'win32') {
+      const { chmodSync } = await import('fs');
+      chmodSync(testServerPath, 0o755);
+    }
+  });
+
+  it('should error and suggest disabling the cyclic tool', async () => {
+    // Just run any command to trigger the schema depth error.
+    // If this test starts failing, check `isSchemaDepthError` from
+    // geminiChat.ts to see if it needs to be updated.
+    // Or, possibly it could mean that gemini has fixed the issue.
+    const output = await rig.run('hello');
+
+    expect(output).toMatch(
+      /Skipping tool 'tool_with_cyclic_schema' from MCP server 'cyclic-schema-server' because it has missing types in its parameter schema/,
+    );
+  });
+});