05-smoke-tests-and-mock-infrastructure.md

layout	default
title	Chapter 5: Smoke Tests and Mock Infrastructure
nav_order	5
parent	MCP Quickstart Resources Tutorial

Chapter 5: Smoke Tests and Mock Infrastructure

Welcome to Chapter 5: Smoke Tests and Mock Infrastructure. In this part of MCP Quickstart Resources Tutorial: Cross-Language MCP Servers and Clients by Example, you will build an intuitive mental model first, then move into concrete implementation details and practical production tradeoffs.

This chapter explains the lightweight test harness used to verify quickstart behavior.

Learning Goals

• run smoke tests across supported language examples
• use mock client/server helpers for isolated protocol checks
• extend test coverage without external API dependencies
• integrate quickstart tests into CI workflows

Test Infrastructure Components

Helper	Role
mcp-test-client.ts	probes server readiness and tool listing
mock-mcp-server.ts	validates client-side protocol calls
smoke-test.sh	orchestrates cross-runtime checks

Source References

• Smoke Tests Guide
• CI Workflow

Summary

You now have a repeatable validation loop for quickstart server/client quality.

Next: Chapter 6: Cross-Language Consistency and Extension Strategy

Source Code Walkthrough

weather-server-python/weather.py

The main function in weather-server-python/weather.py handles a key part of this chapter's functionality:

def main():
    # Initialize and run the server
    mcp.run(transport="stdio")


if __name__ == "__main__":
    main()

This function is important because it defines how MCP Quickstart Resources Tutorial: Cross-Language MCP Servers and Clients by Example implements the patterns covered in this chapter.

weather-server-typescript/src/index.ts

The formatAlert function in weather-server-typescript/src/index.ts handles a key part of this chapter's functionality:

// Format alert data
function formatAlert(feature: AlertFeature): string {
  const props = feature.properties;
  return [
    `Event: ${props.event || "Unknown"}`,
    `Area: ${props.areaDesc || "Unknown"}`,
    `Severity: ${props.severity || "Unknown"}`,
    `Status: ${props.status || "Unknown"}`,
    `Headline: ${props.headline || "No headline"}`,
    "---",
  ].join("\n");
}

interface ForecastPeriod {
  name?: string;
  temperature?: number;
  temperatureUnit?: string;
  windSpeed?: string;
  windDirection?: string;
  shortForecast?: string;
}

interface AlertsResponse {
  features: AlertFeature[];
}

interface PointsResponse {
  properties: {
    forecast?: string;
  };
}

This function is important because it defines how MCP Quickstart Resources Tutorial: Cross-Language MCP Servers and Clients by Example implements the patterns covered in this chapter.

weather-server-typescript/src/index.ts

The main function in weather-server-typescript/src/index.ts handles a key part of this chapter's functionality:

// Start the server
async function main() {
  const transport = new StdioServerTransport();
  await server.connect(transport);
  console.error("Weather MCP Server running on stdio");
}

main().catch((error) => {
  console.error("Fatal error in main():", error);
  process.exit(1);
});

This function is important because it defines how MCP Quickstart Resources Tutorial: Cross-Language MCP Servers and Clients by Example implements the patterns covered in this chapter.

weather-server-typescript/src/index.ts

The AlertFeature interface in weather-server-typescript/src/index.ts handles a key part of this chapter's functionality:

}

interface AlertFeature {
  properties: {
    event?: string;
    areaDesc?: string;
    severity?: string;
    status?: string;
    headline?: string;
  };
}

// Format alert data
function formatAlert(feature: AlertFeature): string {
  const props = feature.properties;
  return [
    `Event: ${props.event || "Unknown"}`,
    `Area: ${props.areaDesc || "Unknown"}`,
    `Severity: ${props.severity || "Unknown"}`,
    `Status: ${props.status || "Unknown"}`,
    `Headline: ${props.headline || "No headline"}`,
    "---",
  ].join("\n");
}

interface ForecastPeriod {
  name?: string;
  temperature?: number;
  temperatureUnit?: string;
  windSpeed?: string;
  windDirection?: string;
  shortForecast?: string;

This interface is important because it defines how MCP Quickstart Resources Tutorial: Cross-Language MCP Servers and Clients by Example implements the patterns covered in this chapter.

How These Components Connect

flowchart TD
    A[main]
    B[formatAlert]
    C[main]
    D[AlertFeature]
    E[ForecastPeriod]
    A --> B
    B --> C
    C --> D
    D --> E

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