fixt test

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2021 Timofey Kovalev
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -1,4 +1,19 @@
 # omg.testingTools
 
----
+This tool can be useful for writing a tests. If you want change private field in struct from imported libraries than it can help you.
 
+```go
+package main
+
+import (
+	"strings"
+
+	"github.com/dedalqq/omg.testingtools"
+)
+
+func TestSomeCase(t *testing.T) {
+	buffer := strings.Builder{}
+
+	testingtools.SetPrivateValue(&buffer, "buf", []byte("data in strings buffer"))
+}
+```

setPrivateValue.go

@@ -6,6 +6,8 @@ import (
 	"unsafe"
 )
 
+// SetPrivateValue sets new a value in to the struct. Use it if you need to get access to private
+// field of the struct from imported package. important: It function must be using only for the tests.
 func SetPrivateValue(obj interface{}, fieldName string, value interface{}) {
 	reflectValue := reflect.ValueOf(obj)
 
@@ -22,23 +24,17 @@ func SetPrivateValue(obj interface{}, fieldName string, value interface{}) {
 
 	newReflectValueType := reflect.TypeOf(value)
 
-	var offset uintptr
+	if fieldType, ok := reflectType.FieldByName(fieldName); ok {
+		currentFieldType := fieldType.Type.String()
 
-	for i := 0; i < reflectValue.NumField(); i++ {
-		if reflectType.Field(i).Name == fieldName {
-			currentFieldType := reflectType.Field(i).Type.String()
-
-			if newReflectValueType.String() != currentFieldType {
-				panic(fmt.Sprintf("incorrect type: must be %s", currentFieldType))
-			}
-
-			fieldPtr := unsafe.Pointer(reflectValue.UnsafeAddr() + offset)
-			reflect.NewAt(newReflectValueType, fieldPtr).Elem().Set(reflect.ValueOf(value))
-
-			return
+		if newReflectValueType.String() != currentFieldType {
+			panic(fmt.Sprintf("incorrect type: must be %s", currentFieldType))
 		}
 
-		offset += reflectValue.Field(i).Type().Size()
+		fieldPtr := unsafe.Pointer(reflectValue.UnsafeAddr() + fieldType.Offset)
+		reflect.NewAt(newReflectValueType, fieldPtr).Elem().Set(reflect.ValueOf(value))
+
+		return
 	}
 
 	panic(fmt.Sprintf("Field [%s] not found in struct", fieldName))

setPrivateValue_test.go

@@ -12,7 +12,7 @@ func TestSetPrivateValue(t *testing.T) {
 	SetPrivateValue(&qq, "c", []int{1, 2, 3, 4})
 	SetPrivateValue(&qq, "b", "qwe")
 
-	if fmt.Sprint(qq) != "{123 qwe [1 2 3 4]}" {
+	if fmt.Sprint(qq) != "{false 123 qwe [1 2 3 4]}" {
 		t.Fail()
 	}
 }

testmodule/omg.go

@@ -1,13 +1,14 @@
 package testmodule
 
 type TestStruct struct {
-	a int
-	b string
-	c []int
+	a bool
+	b int
+	c string
+	d []int
 }
 
 func NewQQ(a int, b string, c []int) TestStruct {
 	return TestStruct{
-		a, b, c,
+		false, a, b, c,
 	}
 }