Detox MCP

Instructions

Implementation Reference

• src/tools/index.ts:328-357 (handler)

  The main handler function for the 'detox_generate_test' tool. It parses input arguments, generates a test file template using generateTestFileTemplate, optionally writes it to a file, and returns the generated code.

  export const generateTestTool: Tool = {
    name: "detox_generate_test",
    description: "Generate a complete Detox test file from a description.",
    inputSchema: zodToJsonSchema(GenerateTestArgsSchema),
    handler: async (args: z.infer<typeof GenerateTestArgsSchema>) => {
      const parsed = GenerateTestArgsSchema.parse(args);
  
      const testCode = generateTestFileTemplate({
        testName: parsed.testName,
        describeName: parsed.testName,
        includeSetup: parsed.includeSetup,
        tests: [
          {
            name: parsed.description,
            code: `    // Test: ${parsed.description}\n    // TODO: Implement test based on the description above`,
          },
        ],
      });
  
      if (parsed.outputPath) {
        await writeFile(parsed.outputPath, testCode, "utf-8");
      }
  
      return {
        success: true,
        code: testCode,
        outputPath: parsed.outputPath,
      };
    },
  };

• src/utils/validators.ts:87-96 (schema)

  Zod schema defining the input parameters for the detox_generate_test tool, including test description, name, output path, setup inclusion, and platform.

  // Generate test schema
  export const GenerateTestArgsSchema = z.object({
    description: z.string().describe("Natural language description of the test scenario"),
    testName: z.string().describe("Name for the test/describe block"),
    outputPath: z.string().optional().describe("Where to write the generated test file"),
    includeSetup: z.boolean().optional().default(true),
    platform: z.enum(["ios", "android", "cross-platform"]).optional().default("cross-platform"),
  });
  
  export type GenerateTestArgs = z.infer<typeof GenerateTestArgsSchema>;

• src/templates/test-templates.ts:5-43 (helper)

  Core helper function that generates the Detox test file template code, including describe block, beforeAll/beforeEach hooks, and it test stubs. Called by the tool handler.

  export function generateTestFileTemplate(options: {
    testName: string;
    describeName?: string;
    includeSetup?: boolean;
    tests?: Array<{ name: string; code: string }>;
  }): string {
    const describeName = options.describeName || options.testName;
    const tests = options.tests || [
      { name: "should work correctly", code: "    // TODO: Add test implementation" },
    ];
  
    const testCases = tests
      .map(
        (t) => `
    it('${t.name}', async () => {
  ${t.code}
    });`
      )
      .join("\n");
  
    if (options.includeSetup !== false) {
      return `describe('${describeName}', () => {
    beforeAll(async () => {
      await device.launchApp();
    });
  
    beforeEach(async () => {
      await device.reloadReactNative();
    });
  ${testCases}
  });
  `;
    }
  
    return `describe('${describeName}', () => {
  ${testCases}
  });
  `;
  }

• src/tools/index.ts:429-442 (registration)

  The allTools array exports the generateTestTool (at index position line 438), registering it for use in the MCP tools system.

  export const allTools: Tool[] = [
    buildTool,
    testTool,
    initTool,
    readConfigTool,
    listConfigurationsTool,
    validateConfigTool,
    createConfigTool,
    listDevicesTool,
    generateTestTool,
    generateMatcherTool,
    generateActionTool,
    generateExpectationTool,
  ];