Method Validate

expr/http_endpoint.go:1001–1061

Validate validates a route expression by ensuring that the route parameters can be inferred from the method payload and there is no duplicate parameters in an absolute route.

()

// can be inferred from the method payload and there is no duplicate parameters
// in an absolute route.
func (r *RouteExpr) Validate() *eval.ValidationErrors {
	verr := new(eval.ValidationErrors)

	// Make sure route params are defined in the method payload
	if rparams := r.Params(); len(rparams) > 0 {
		if r.Endpoint.MethodExpr.Payload == nil {
			verr.Add(r, "Route parameters are defined, but method payload is not defined.")
		} else {
			switch r.Endpoint.MethodExpr.Payload.Type.(type) {
			case *Map:
				verr.Add(r, "Route parameters are defined, but method payload is a map. Method payload must be a primitive or an object.")
			case *Object, UserType:
				for _, p := range rparams {
					if r.Endpoint.MethodExpr.Payload.Find(p) == nil {
						verr.Add(r, "Route param %q not found in method payload", p)
					}
				}
			}
			if len(rparams) > 1 && IsPrimitive(r.Endpoint.MethodExpr.Payload.Type) {
				verr.Add(r, "Multiple route parameters are defined, but method payload is a primitive. Only one router parameter can be defined if payload is primitive.")
			}
		}
	}

	// Make sure there's no duplicate params in absolute route
	paths := r.FullPaths()
	for _, path := range paths {
		matches := HTTPWildcardRegex.FindAllStringSubmatch(path, -1)
		wcs := make(map[string]struct{}, len(matches))
		for _, match := range matches {
			if _, ok := wcs[match[1]]; ok {
				verr.Add(r, "Wildcard %q appears multiple times in full path %q", match[1], path)
			}
			wcs[match[1]] = struct{}{}
		}
	}

	// For WebSocket streaming endpoints, only GET is supported
	// SSE endpoints can use both GET and POST (JSON-RPC SSE uses POST)
	if r.Endpoint.MethodExpr.IsStreaming() && len(r.Endpoint.Responses) > 0 && r.Endpoint.SSE == nil {
		if r.Method != "GET" {
			verr.Add(r, "WebSocket endpoint supports only \"GET\" method. Got %q.", r.Method)
		}
	}

	// HEAD method must not return a response body as per RFC 2616 section 9.4
	if r.Method == "HEAD" {
		disallowBody := func(resp *HTTPResponseExpr) {
			if httpResponseBody(r.Endpoint, resp).Type != Empty {
				verr.Add(r, "HTTP status %d: Response body defined for HEAD method which does not allow response body.", resp.StatusCode)
			}
		}
		for _, resp := range r.Endpoint.Responses {
			disallowBody(resp)
		}
		for _, e := range r.Endpoint.HTTPErrors {
			disallowBody(e.Response)
		}