refactor: sort (#21)

Removed reverse func because it use to much cpu and add test cas for asc sort

slice/slice.go

@@ -523,18 +523,38 @@ func SortByField(slice interface{}, field string, sortType ...string) error {
 	}
 
 	// Create a less function based on the field's kind.
-	var less func(a, b reflect.Value) bool
+	var compare func(a, b reflect.Value) bool
 	switch sf.Type.Kind() {
 	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-		less = func(a, b reflect.Value) bool { return a.Int() < b.Int() }
+		if len(sortType) > 0 && sortType[0] == "desc" {
+			compare = func(a, b reflect.Value) bool { return a.Int() > b.Int() }
+		} else {
+			compare = func(a, b reflect.Value) bool { return a.Int() < b.Int() }
+		}
 	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
-		less = func(a, b reflect.Value) bool { return a.Uint() < b.Uint() }
+		if len(sortType) > 0 && sortType[0] == "desc" {
+			compare = func(a, b reflect.Value) bool { return a.Uint() > b.Uint() }
+		} else {
+			compare = func(a, b reflect.Value) bool { return a.Uint() < b.Uint() }
+		}
 	case reflect.Float32, reflect.Float64:
-		less = func(a, b reflect.Value) bool { return a.Float() < b.Float() }
+		if len(sortType) > 0 && sortType[0] == "desc" {
+			compare = func(a, b reflect.Value) bool { return a.Float() > b.Float() }
+		} else {
+			compare = func(a, b reflect.Value) bool { return a.Float() < b.Float() }
+		}
 	case reflect.String:
-		less = func(a, b reflect.Value) bool { return a.String() < b.String() }
+		if len(sortType) > 0 && sortType[0] == "desc" {
+			compare = func(a, b reflect.Value) bool { return a.String() > b.String() }
+		} else {
+			compare = func(a, b reflect.Value) bool { return a.String() < b.String() }
+		}
 	case reflect.Bool:
-		less = func(a, b reflect.Value) bool { return !a.Bool() && b.Bool() }
+		if len(sortType) > 0 && sortType[0] == "desc" {
+			compare = func(a, b reflect.Value) bool { return a.Bool() && !b.Bool() }
+		} else {
+			compare = func(a, b reflect.Value) bool { return !a.Bool() && b.Bool() }
+		}
 	default:
 		return fmt.Errorf("field type %s not supported", sf.Type)
 	}
@@ -548,24 +568,12 @@ func SortByField(slice interface{}, field string, sortType ...string) error {
 		}
 		a = a.FieldByIndex(sf.Index)
 		b = b.FieldByIndex(sf.Index)
-		return less(a, b)
+		return compare(a, b)
 	})
 
-	if sortType[0] == "desc" {
-		reverseSlice(slice)
-	}
 	return nil
 }
 
-// todo remove after migration
-func reverseSlice(slice interface{}) {
-	sv := sliceValue(slice)
-	swp := reflect.Swapper(sv.Interface())
-	for i, j := 0, sv.Len()-1; i < j; i, j = i+1, j-1 {
-		swp(i, j)
-	}
-}
-
 // Without creates a slice excluding all given values
 func Without[T comparable](slice []T, values ...T) []T {
 	if len(values) == 0 || len(slice) == 0 {

slice/slice_test.go

@@ -381,7 +381,7 @@ func TestDifference(t *testing.T) {
 	assert.Equal([]int{1, 2, 3}, Difference(s1, s2))
 }
 
-func TestSortByField(t *testing.T) {
+func TestSortByFieldDesc(t *testing.T) {
 	assert := internal.NewAssert(t, "TestSortByField")
 
 	type student struct {
@@ -406,6 +406,31 @@ func TestSortByField(t *testing.T) {
 
 	assert.Equal(students, studentsOfSortByAge)
 }
+func TestSortByFieldAsc(t *testing.T) {
+	assert := internal.NewAssert(t, "TestSortByField")
+
+	type student struct {
+		name string
+		age  int
+	}
+	students := []student{
+		{"a", 10},
+		{"b", 15},
+		{"c", 5},
+		{"d", 6},
+	}
+	studentsOfSortByAge := []student{
+		{"c", 5},
+		{"d", 6},
+		{"a", 10},
+		{"b", 15},
+	}
+
+	err := SortByField(students, "age")
+	assert.IsNil(err)
+
+	assert.Equal(students, studentsOfSortByAge)
+}
 
 func TestWithout(t *testing.T) {
 	assert := internal.NewAssert(t, "TestWithout")