Request wrapper remove http.Request

README.md

@@ -312,21 +312,21 @@ If you need to access http request attributes wrap the input with `fetch.Request
 type Pet struct {
     Name string
 }
-http.HandleFunc("/pets", fetch.ToHandlerFunc(func(in fetch.Request[Pet]) (*fetch.Empty, error) {
-    fmt.Println("Request context:", in.Context())
-    fmt.Println("Authorization header:", in.Headers["Authorization"])
-	fmt.Println("Pet:", in.Body)
-	fmt.Println("Pet's name:", in.Body.Name)
+http.HandleFunc("/pets", fetch.ToHandlerFunc(func(req fetch.Request[Pet]) (*fetch.Empty, error) {
+    fmt.Println("Request context:", req.Context)
+    fmt.Println("Authorization header:", req.Headers["Authorization"])
+	fmt.Println("Pet:", req.Body)
+	fmt.Println("Pet's name:", req.Body.Name)
     return nil, nil
 }))
 ```
-If you have go1.22 and above you can access the wildcards as well.
+If you have go1.23 and above you can access the wildcards as well.
 ```go
 http.HandleFunc("GET /pets/{id}", fetch.ToHandlerFunc(func(in fetch.Request[fetch.Empty]) (*fetch.Empty, error) {
-    fmt.Println("id from url:", in.PathValue("id"))
+    fmt.Println("id from url:", in.PathValues["id"])
     return nil, nil
 }))
-```
+``` 
 To customize http attributes of the response, wrap the output with `fetch.Response`
 ```go
 http.HandleFunc("/pets", fetch.ToHandlerFunc(func(_ fetch.Empty) (fetch.Response[*Pet], error) {

to_handler.go

@@ -5,6 +5,8 @@ import (
 	"io"
 	"net/http"
 	"reflect"
+	"runtime"
+	"strings"
 )
 
 var defaultHandlerConfig = HandlerConfig{
@@ -81,7 +83,8 @@ func ToHandlerFunc[In any, Out any](apply ApplyFunc[In, Out]) http.HandlerFunc {
 				}
 			}
 			valueOf := reflect.Indirect(reflect.ValueOf(&in))
-			valueOf.FieldByName("Request").Set(reflect.ValueOf(r))
+			valueOf.FieldByName("PathValues").Set(reflect.ValueOf(extractPathValues(r)))
+			valueOf.FieldByName("Context").Set(reflect.ValueOf(r.Context()))
 			valueOf.FieldByName("Headers").Set(reflect.ValueOf(uniqueHeaders(r.Header)))
 			valueOf.FieldByName("Body").Set(reflect.ValueOf(resInstance).Elem())
 		} else if !isEmptyType(in) {
@@ -115,3 +118,37 @@ func ToHandlerFunc[In any, Out any](apply ApplyFunc[In, Out]) http.HandlerFunc {
 		}
 	}
 }
+
+func extractPathValues(r *http.Request) map[string]string {
+	if !isGo23AndAbove() || r == nil {
+		return map[string]string{}
+	}
+
+	req := reflect.ValueOf(r)
+
+	parts := strings.Split(req.Elem().FieldByName("Pattern").String(), "/")
+	result := make(map[string]string)
+	for _, part := range parts {
+		if len(part) > 2 && strings.HasPrefix(part, "{") && strings.HasSuffix(part, "}") {
+			wildcard := part[1 : len(part)-1]
+			values := req.MethodByName("PathValue").Call([]reflect.Value{reflect.ValueOf(wildcard)})
+			if len(values) != 1 {
+				continue
+			}
+			if v := values[0].String(); v != "" {
+				result[wildcard] = v
+			}
+		}
+	}
+	return result
+}
+
+func isGo23AndAbove() bool {
+	if strings.HasPrefix(runtime.Version(), "go1.21") {
+		return false
+	}
+	if strings.HasPrefix(runtime.Version(), "go1.22") {
+		return false
+	}
+	return true
+}

to_handler_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"net/http"
 	"testing"
+	_ "unsafe"
 )
 
 func TestToHandlerFunc_EmptyIn(t *testing.T) {
@@ -88,7 +89,7 @@ func TestToHandlerFunc_Header(t *testing.T) {
 
 func TestToHandlerFunc_Context(t *testing.T) {
 	f := ToHandlerFunc(func(in Request[Empty]) (Empty, error) {
-		assert(t, in.Context().Err(), nil)
+		assert(t, in.Context.Err(), nil)
 		return Empty{}, nil
 	})
 	mw := newMockWriter()
@@ -153,3 +154,28 @@ func TestToHandlerFunc_Middleware(t *testing.T) {
 	mux.ServeHTTP(mw, r)
 	assert(t, mw.status, 422)
 }
+
+// to run it, update go.mod to 1.23
+//func TestToHandlerFunc_ExtractPathValues(t *testing.T) {
+//	mw := newMockWriter()
+//	mux := http.NewServeMux()
+//	mux.HandleFunc("POST /categories/{category}/ids/{id}", func(w http.ResponseWriter, r *http.Request) {
+//		res := extractPathValues(r)
+//		if len(res) != 2 || res["category"] != "cats" || res["id"] != "1" {
+//			t.Errorf("extractPathValues(r) got: %+v", res)
+//		}
+//		w.WriteHeader(422)
+//	})
+//	r, err := http.NewRequest("POST", "/categories/cats/ids/1", bytes.NewBuffer([]byte(`{"name":"Charles"}`)))
+//	assert(t, err, nil)
+//	mux.ServeHTTP(mw, r)
+//	assert(t, mw.status, 422)
+//}
+
+func TestToHandlerFunc_ExtractPathValues_GoLess23(t *testing.T) {
+	if !isGo23AndAbove() {
+		if len(extractPathValues(&http.Request{})) != 0 {
+			t.Errorf("expect zero map")
+		}
+	}
+}

wrappers.go

@@ -1,7 +1,7 @@
 package fetch
 
 import (
-	"net/http"
+	"context"
 	"reflect"
 	"strings"
 )
@@ -54,9 +54,14 @@ e.g.
 	}))
 */
 type Request[T any] struct {
-	*http.Request
-	Headers map[string]string
-	Body    T
+	Context context.Context
+	// Only available in go1.23 and above.
+	// PathValue was introduced in go1.22 but
+	// there was no reliable way to extract them.
+	// go1.23 introduced http.Request.Pattern allowing to list the wildcards.
+	PathValues map[string]string
+	Headers    map[string]string
+	Body       T
 }
 
 // Empty represents an empty response or request body, skipping JSON handling.