Add GetEndpoint test case for EndpointFunc and fix empty request handling

xapi/endpoint.go

@@ -3,6 +3,7 @@ package xapi
 import (
 	"context"
 	"encoding/json"
+	"io"
 	"net/http"
 )
 
@@ -69,13 +70,18 @@ func (e *Endpoint[TReq, TRes]) Handler() http.Handler {
 	h := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		var req TReq
 
-		if r.Body != nil {
-			if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		data, err := io.ReadAll(r.Body)
+		if err != nil {
+			e.opts.errorHandler.HandleError(w, err)
+			return
+		}
+		defer r.Body.Close()
+
+		if len(data) > 0 {
+			if err := json.Unmarshal(data, &req); err != nil {
 				e.opts.errorHandler.HandleError(w, err)
 				return
 			}
-
-			defer r.Body.Close()
 		}
 
 		if extracter, ok := any(&req).(Extracter); ok {

xapi/endpoint_test.go

@@ -48,6 +48,34 @@ func TestEndpoint_Handler(t *testing.T) {
 		}`, rec.Body.String())
 	})
 
+	t.Run("GetEndpoint", func(t *testing.T) {
+		t.Parallel()
+
+		rec := httptest.NewRecorder()
+
+		handler := EndpointFunc[EmptyRequest, BasicResponse](
+			func(ctx context.Context, req *EmptyRequest) (*BasicResponse, error) {
+				return &BasicResponse{
+					Message: "Hello Tester",
+					ID:      321,
+				}, nil
+			},
+		)
+
+		endpoint := NewEndpoint(handler)
+		req := httptest.NewRequest(http.MethodGet, "/test?name=Tester", nil)
+		req.Header.Set("Content-Type", "application/json")
+
+		endpoint.Handler().ServeHTTP(rec, req)
+
+		assert.Equal(t, http.StatusOK, rec.Result().StatusCode)
+		assert.Equal(t, "application/json; charset=utf-8", rec.Header().Get("Content-Type"))
+		assert.JSONEq(t, `{
+			"message": "Hello Tester",
+			"id": 321
+		}`, rec.Body.String())
+	})
+
 	t.Run("WithValidation", func(t *testing.T) {
 		t.Parallel()
 
@@ -443,6 +471,8 @@ func TestEndpoint_ContextCancellation(t *testing.T) {
 
 // Test types and implementations
 
+type EmptyRequest struct{}
+
 type BasicRequest struct {
 	Name string `json:"name"`
 }