Playwright MCP Server

Instructions

Implementation Reference

• src/tools/codegen/index.ts:82-158 (handler)

  Full Tool definition including the handler function that ends the codegen session by generating and saving a Playwright test file from recorded actions, cleaning up browser resources, and returning the generated file path.

  export const endCodegenSession: Tool = {
    name: 'end_codegen_session',
    description: 'End the current code generation session and generate Playwright test',
    parameters: {
      type: 'object',
      properties: {
        sessionId: {
          type: 'string',
          description: 'ID of the session to end'
        }
      },
      required: ['sessionId']
    },
    handler: async ({ sessionId }: { sessionId: string }) => {
      try {
        const recorder = ActionRecorder.getInstance();
        const session = recorder.endSession(sessionId);
  
        if (!session) {
          throw new Error(`Session ${sessionId} not found`);
        }
  
        if (!session.options) {
          throw new Error(`Session ${sessionId} has no options configured`);
        }
  
        const generator = new PlaywrightGenerator(session.options);
        const result = await generator.generateTest(session);
  
        // Double check output directory exists
        const outputDir = path.dirname(result.filePath);
        await fs.mkdir(outputDir, { recursive: true });
        
        // Write test file
        try {
          await fs.writeFile(result.filePath, result.testCode, 'utf-8');
        } catch (writeError: any) {
          throw new Error(`Failed to write test file: ${writeError.message}`);
        }
  
        // Close Playwright browser and cleanup
        try {
          if (global.browser?.isConnected()) {
            await global.browser.close();
          }
        } catch (browserError: any) {
          console.warn('Failed to close browser:', browserError.message);
        } finally {
          global.browser = undefined;
          global.page = undefined;
        }
  
        const absolutePath = path.resolve(result.filePath);
  
        return {
          filePath: absolutePath,
          outputDirectory: outputDir,
          testCode: result.testCode,
          message: `Generated test file at: ${absolutePath}\nOutput directory: ${outputDir}`
        };
      } catch (error: any) {
        // Ensure browser cleanup even on error
        try {
          if (global.browser?.isConnected()) {
            await global.browser.close();
          }
        } catch {
          // Ignore cleanup errors
        } finally {
          global.browser = undefined;
          global.page = undefined;
        }
        
        throw new Error(`Failed to end codegen session: ${error.message}`);
      }
    }
  };

• src/tools.ts:37-49 (schema)

  MCP tool schema definition used for input validation and tool registration.

    name: "end_codegen_session",
    description: "End a code generation session and generate the test file",
    inputSchema: {
      type: "object",
      properties: {
        sessionId: { 
          type: "string", 
          description: "ID of the session to end" 
        }
      },
      required: ["sessionId"]
    }
  },

• src/toolHandler.ts:363-373 (registration)

  Registration and dispatch logic in the main tool handler that routes 'end_codegen_session' calls to its handler function.

  // Handle codegen tools
  switch (name) {
    case 'start_codegen_session':
      return await handleCodegenResult(startCodegenSession.handler(args));
    case 'end_codegen_session':
      return await handleCodegenResult(endCodegenSession.handler(args));
    case 'get_codegen_session':
      return await handleCodegenResult(getCodegenSession.handler(args));
    case 'clear_codegen_session':
      return await handleCodegenResult(clearCodegenSession.handler(args));
  }

• src/tools.ts:484-490 (registration)

  Array listing codegen tools including 'end_codegen_session' for categorization and tool list composition.

  // Codegen tools
  export const CODEGEN_TOOLS = [
    'start_codegen_session',
    'end_codegen_session',
    'get_codegen_session',
    'clear_codegen_session'
  ];