User book API: use a single query with result and count

internal/apitest/get_user_book_test.go

@@ -13,6 +13,11 @@ import (
 )
 
 type bookUserGet struct {
+	Count int64             `json:"count"`
+	Books []bookUserGetBook `json:"books"`
+}
+
+type bookUserGetBook struct {
 	BookId   uint   `json:"id"`
 	Title    string `json:"title" binding:"required,max=300"`
 	Author   string `json:"author" binding:"max=100"`
@@ -21,14 +26,14 @@ type bookUserGet struct {
 	WantRead bool   `json:"wantread"`
 }
 
-func testGetbooksHandler(t *testing.T, router *gin.Engine, userToken string, expectedCode int, url string) []bookUserGet {
+func testGetbooksHandler(t *testing.T, router *gin.Engine, userToken string, expectedCode int, url string) bookUserGet {
 	req, _ := http.NewRequest("GET", url, nil)
 	req.Header.Add("Authorization", fmt.Sprintf("Bearer %s", userToken))
 
 	w := httptest.NewRecorder()
 	router.ServeHTTP(w, req)
 
-	var parsedResponse []bookUserGet
+	var parsedResponse bookUserGet
 	err := json.Unmarshal(w.Body.Bytes(), &parsedResponse)
 	if err != nil {
 		t.Error(err)