fix infinitely app.Test (gofiber#1997)

* diff

* better code

* err message

* code style

* up

* fix type error

* use time.Timer

app.go

@@ -845,7 +845,15 @@ func (app *App) Test(req *http.Request, msTimeout ...int) (resp *http.Response,
 	// Serve conn to server
 	channel := make(chan error)
 	go func() {
+		var returned bool
+		defer func() {
+			if !returned {
+				channel <- fmt.Errorf("runtime.Goexit() called in handler or server panic")
+			}
+		}()
+
 		channel <- app.server.ServeConn(conn)
+		returned = true
 	}()
 
 	// Wait for callback

app_test.go

@@ -16,6 +16,7 @@ import (
 	"net/http/httptest"
 	"reflect"
 	"regexp"
+	"runtime"
 	"strings"
 	"testing"
 	"time"
@@ -1527,3 +1528,35 @@ func Test_App_UseMountedErrorHandlerForBestPrefixMatch(t *testing.T) {
 	utils.AssertEqual(t, nil, err, "iotuil.ReadAll()")
 	utils.AssertEqual(t, "hi, i'm a custom sub sub fiber error", string(b), "Third fiber Response body")
 }
+
+func Test_App_Test_no_timeout_infinitely(t *testing.T) {
+	var err error
+	c := make(chan int)
+
+	go func() {
+		defer func() { c <- 0 }()
+		app := New()
+		app.Get("/", func(c *Ctx) error {
+			runtime.Goexit()
+			return nil
+		})
+
+		req := httptest.NewRequest(http.MethodGet, "/", http.NoBody)
+		_, err = app.Test(req, -1)
+	}()
+
+	tk := time.NewTimer(5 * time.Second)
+	defer tk.Stop()
+
+	select {
+	case <-tk.C:
+		t.Error("hanging test")
+		t.FailNow()
+	case <-c:
+	}
+
+	if err == nil {
+		t.Error("unexpected success request")
+		t.FailNow()
+	}
+}