mcp-playwright

Instructions

Implementation Reference

• src/tools/codegen/index.ts:26-81 (handler)

  Primary implementation of the 'start_codegen_session' tool, including handler function that initializes a codegen session with ActionRecorder, merges options, ensures output directory, and returns session details.

  export const startCodegenSession: Tool = {
    name: "start_codegen_session",
    description: "Start a new code generation session to record MCP tool actions",
    parameters: {
      type: "object",
      properties: {
        options: {
          type: "object",
          description: "Code generation options",
          properties: {
            outputPath: { type: "string" },
            testNamePrefix: { type: "string" },
            includeComments: { type: "boolean" },
          },
        },
      },
    },
    handler: async ({ options = {} }: { options?: CodegenOptions }, _context?: { server?: any }) => {
      try {
        // Merge provided options with defaults
        const mergedOptions = { ...DEFAULT_OPTIONS, ...options };
  
        // Ensure output path is absolute and normalized
        const workspaceRoot = getWorkspaceRoot();
        const outputPath = path.isAbsolute(mergedOptions.outputPath)
          ? mergedOptions.outputPath
          : path.join(workspaceRoot, mergedOptions.outputPath);
  
        mergedOptions.outputPath = outputPath;
  
        // Ensure output directory exists
        try {
          await fs.mkdir(outputPath, { recursive: true });
        } catch (mkdirError: any) {
          throw new Error(`Failed to create output directory: ${mkdirError.message}`);
        }
  
        const sessionId = ActionRecorder.getInstance().startSession();
  
        // Store options with the session
        const recorder = ActionRecorder.getInstance();
        const session = recorder.getSession(sessionId);
        if (session) {
          session.options = mergedOptions;
        }
  
        return {
          sessionId,
          options: mergedOptions,
          message: `Started codegen session. Tests will be generated in: ${outputPath}`,
        };
      } catch (error: any) {
        throw new Error(`Failed to start codegen session: ${error.message}`);
      }
    },
  };

• src/tools.ts:7-35 (schema)

  Input schema definition for 'start_codegen_session' used in createToolDefinitions for MCP tool discovery.

  {
    name: "start_codegen_session",
    description: "Start a new code generation session to record Playwright actions",
    inputSchema: {
      type: "object",
      properties: {
        options: {
          type: "object",
          description: "Code generation options",
          properties: {
            outputPath: {
              type: "string",
              description: "Directory path where generated tests will be saved (use absolute path)",
            },
            testNamePrefix: {
              type: "string",
              description: "Prefix to use for generated test names (default: 'GeneratedTest')",
            },
            includeComments: {
              type: "boolean",
              description: "Whether to include descriptive comments in generated tests",
            },
          },
          required: ["outputPath"],
        },
      },
      required: ["options"],
    },
  },

• src/toolHandler.ts:431-440 (registration)

  Registration and dispatch logic for codegen tools including 'start_codegen_session' in the main tool call handler switch statement.

  switch (name) {
    case "start_codegen_session":
      return await handleCodegenResult(startCodegenSession.handler(args, { server }));
    case "end_codegen_session":
      return await handleCodegenResult(endCodegenSession.handler(args, { server }));
    case "get_codegen_session":
      return await handleCodegenResult(getCodegenSession.handler(args, { server }));
    case "clear_codegen_session":
      return await handleCodegenResult(clearCodegenSession.handler(args, { server }));
  }

• src/toolHandler.ts:37-40 (registration)

  Import statement registering the startCodegenSession tool from codegen/index.ts into the main toolHandler.

  clearCodegenSession,
  endCodegenSession,
  getCodegenSession,
  startCodegenSession,

• src/tools/codegen/index.ts:219-219 (schema)

  Export of codegenTools array including startCodegenSession for registration.

  export const codegenTools = [startCodegenSession, endCodegenSession, getCodegenSession, clearCodegenSession];