HTMX
HTMX handles server communication and DOM swaps; Alpine.js handles client-side interactivity within those swapped elements. Testing them together requires three layers: Alpine.js component unit tests (using @alpinejs/test), HTMX server-side partial tests (using your backend test client), and E2E tests (Playwright) for the full interaction cycle. Key Takeaways
HTMX
Go's net/http/httptest package makes testing HTMX endpoints straightforward — create a recorder, set the HX-Request header, call your handler, and assert on the HTML response. This works with any Go web framework: Gin, Chi, Echo, or stdlib http.ServeMux. Go's speed makes HTMX integration tests
HTMX
FastAPI is popular for APIs, but with Jinja2 templates it's a great HTMX backend too. Testing HTMX with FastAPI means using FastAPI's TestClient (Starlette-based) to send HX-Request headers and assert on HTML fragment responses, plus Playwright for browser-level interaction tests. Key Takeaways Use TestClient with headers=
HTMX
Rails and HTMX are a natural fit — ERB templates serve HTML partials, and Rails' request specs test them efficiently. Testing HTMX in Rails means adding the HX-Request header to request specs, using Capybara for browser tests, and validating HTMX response headers like HX-Trigger and HX-Redirect. Key Takeaways Use headers:
HTMX
HTMX turns Django into a hypermedia-first framework where server responses are HTML fragments (partials) instead of JSON. Testing HTMX with Django means testing two layers: server-side partial rendering (Django TestClient with HX-Request header) and browser-side interaction (Playwright E2E). This guide covers both. Key Takeaways Test partials with HX-Request: true header.