HelpMeTest Proxy Setup

Sets up proxy tunnels to test local development servers through HelpMeTest.

Purpose

HelpMeTest tests run against URLs (http://localhost, http://my.app.com). For local development, the proxy tunnels these URLs to your local ports so tests can access your dev servers.

When to Use

• Testing against localhost during development
• Substituting production URLs with local versions
• Routing frontend and backend on different ports
• Before writing or running any local tests

Quick Start

Basic setup:

# If your app runs on port 3000
helpmetest proxy start localhost:3000

Verify it works:

# Use HelpMeTest interactive command
helpmetest_run_interactive_command({ command: "Go To  http://localhost" })
# Should load your local app

Then write/run tests using:

Go To  http://localhost

Three Proxy Strategies

Strategy 1: Single Tunnel to Frontend

When to use: Your dev server already proxies some routes internally (e.g., /api → backend port)

Setup:

# Frontend on port 5001, it proxies /api internally to port 3001
helpmetest proxy start localhost:5001

In tests:

Go To  http://localhost
# Both UI and /api calls work through the single tunnel

Example: Vite, webpack-dev-server with proxy configuration

Strategy 2: Separate Tunnels for Frontend and Backend

When to use:

• Services need different hostnames (cookies, CORS)
• You want explicit separation in tests
• No internal proxy configured

Setup:

# Frontend on port 5001
helpmetest proxy start frontend.local:5001

# Backend on port 3001
helpmetest proxy start backend.local:3001

In tests:

Go To  http://frontend.local      # For UI
# API calls use http://backend.local/api

Strategy 3: Substitute Production with Local

When to use:

• You have tests running against production URLs
• Want to test local changes without modifying test code
• Need production domain for cookies/sessions

Setup:

# Intercept my.awesome.app and route to local port 3000
helpmetest proxy start my.awesome.app:80:3000

In tests:

Go To  http://my.awesome.app
# Routes to localhost:3000 instead of production

The port mapping format:

• domain - hostname in test URLs
• external_port - port in test URLs (usually 80 for HTTP, 443 for HTTPS)
• source_port - your local development port

Example: Production tests use http://my.awesome.app:80, but you want to test local code running on port 3000

Verification

After starting proxy, always verify using HelpMeTest:

The proxy only intercepts traffic within HelpMeTest's infrastructure. Use interactive commands to verify:

# For localhost
helpmetest_run_interactive_command({ command: "Go To  http://localhost" })

# For custom hostnames
helpmetest_run_interactive_command({ command: "Go To  http://frontend.local" })

# For production substitution
helpmetest_run_interactive_command({ command: "Go To  http://my.awesome.app" })

Expected: You should see your local app load successfully, not a connection error.

If verification fails: Don't write tests yet - fix the proxy setup first.

Troubleshooting

Tests can't reach the URL

Check proxy is running:

ps aux | grep "helpmetest proxy"

Check local server is running:

# Direct connection to your local port (bypasses proxy)
curl http://127.0.0.1:3000

Check proxy output shows your tunnel:

✓ Proxying localhost -> localhost:3000
# or
✓ Proxying frontend.local -> localhost:5001

If tunnel missing: Restart the proxy command

Custom hostname not resolving (frontend.local, etc.)

Custom hostnames are handled by the proxy - you don't need to edit /etc/hosts. If verification fails:

1. Verify proxy is running
2. Check the exact hostname in proxy output
3. Ensure you're using HTTP (not HTTPS) unless you configured SSL

Production substitution not working

Check port mapping:

# Wrong (missing source port)
helpmetest proxy start my.awesome.app:80

# Correct
helpmetest proxy start my.awesome.app:80:3000

Verify substitution:

# Use HelpMeTest to verify routing
helpmetest_run_interactive_command({ command: "Go To  http://my.awesome.app" })
# Should load from localhost:3000, not production

Multiple Services Example

Complex setup with frontend, backend, and production substitution:

# Local frontend
helpmetest proxy start frontend.local:5001

# Local backend API
helpmetest proxy start api.local:3001

# Production service running locally
helpmetest proxy start prod.myapp.com:80:8000

Tests can now use all three:

Go To  http://frontend.local
# Make API call to http://api.local/endpoint
# Access production service at http://prod.myapp.com

Best Practices

1. Start proxy BEFORE writing tests - Don't waste time debugging test failures caused by proxy not running

2. Always verify with HelpMeTest - Use helpmetest_run_interactive_command to confirm routing works before writing automated tests

3. Choose simplest strategy - If frontend already proxies backend, use Strategy 1 (single tunnel)

4. Keep proxy running - Start in background/separate terminal, don't restart unnecessarily

5. Use consistent hostnames - If you use frontend.local in one test, use it in all tests for that service

Output Messages

Success:

✓ Proxying localhost -> localhost:3000

Already exists (safe to ignore):

[W] new proxy type error: proxy already exists

Means tunnel is already registered - your tests will still work.

Version: 0.1