Add trim left and right normalizers and tests to v2. (#145)

# Describe Request

Add trim left and right normalizers and tests to v2.

# Change Type

New code.

v2/maker.go

@@ -34,6 +34,8 @@ var makers = map[string]MakeCheckFunc{
 	nameMaxLen:       makeMaxLen,
 	nameMinLen:       makeMinLen,
 	nameRequired:     makeRequired,
+	nameTrimLeft:     makeTrimLeft,
+	nameTrimRight:    makeTrimRight,
 	nameTrimSpace:    makeTrimSpace,
 	nameURL:          makeURL,
 	nameURLEscape:    makeURLEscape,

v2/trim_left.go

@@ -0,0 +1,32 @@
+// Copyright (c) 2023-2024 Onur Cinar.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+// https://github.com/cinar/checker
+
+package v2
+
+import (
+	"reflect"
+	"strings"
+)
+
+const (
+	// nameTrimLeft is the name of the trim left normalizer.
+	nameTrimLeft = "trim-left"
+)
+
+// TrimLeft returns the value of the string with whitespace removed from the beginning.
+func TrimLeft(value string) (string, error) {
+	return strings.TrimLeft(value, " \t"), nil
+}
+
+// reflectTrimLeft returns the value of the string with whitespace removed from the beginning.
+func reflectTrimLeft(value reflect.Value) (reflect.Value, error) {
+	newValue, err := TrimLeft(value.Interface().(string))
+	return reflect.ValueOf(newValue), err
+}
+
+// makeTrimLeft returns the trim left normalizer function.
+func makeTrimLeft(_ string) CheckFunc[reflect.Value] {
+	return reflectTrimLeft
+}

v2/trim_left_test.go

@@ -0,0 +1,47 @@
+// Copyright (c) 2023-2024 Onur Cinar.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+// https://github.com/cinar/checker
+
+package v2_test
+
+import (
+	"testing"
+
+	v2 "github.com/cinar/checker/v2"
+)
+
+func TestTrimLeft(t *testing.T) {
+	input := "    test    "
+	expected := "test    "
+
+	actual, err := v2.TrimLeft(input)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if actual != expected {
+		t.Fatalf("actual %s expected %s", actual, expected)
+	}
+}
+
+func TestReflectTrimLeft(t *testing.T) {
+	type Person struct {
+		Name string `checkers:"trim-left"`
+	}
+
+	person := &Person{
+		Name: "    test    ",
+	}
+
+	expected := "test    "
+
+	errs, ok := v2.CheckStruct(person)
+	if !ok {
+		t.Fatalf("got unexpected errors %v", errs)
+	}
+
+	if person.Name != expected {
+		t.Fatalf("actual %s expected %s", person.Name, expected)
+	}
+}

v2/trim_right.go

@@ -0,0 +1,32 @@
+// Copyright (c) 2023-2024 Onur Cinar.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+// https://github.com/cinar/checker
+
+package v2
+
+import (
+	"reflect"
+	"strings"
+)
+
+const (
+	// nameTrimRight is the name of the trim right normalizer.
+	nameTrimRight = "trim-right"
+)
+
+// TrimRight returns the value of the string with whitespace removed from the end.
+func TrimRight(value string) (string, error) {
+	return strings.TrimRight(value, " \t"), nil
+}
+
+// reflectTrimRight returns the value of the string with whitespace removed from the end.
+func reflectTrimRight(value reflect.Value) (reflect.Value, error) {
+	newValue, err := TrimRight(value.Interface().(string))
+	return reflect.ValueOf(newValue), err
+}
+
+// makeTrimRight returns the trim right normalizer function.
+func makeTrimRight(_ string) CheckFunc[reflect.Value] {
+	return reflectTrimRight
+}

v2/trim_right_test.go

@@ -0,0 +1,47 @@
+// Copyright (c) 2023-2024 Onur Cinar.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+// https://github.com/cinar/checker
+
+package v2_test
+
+import (
+	"testing"
+
+	v2 "github.com/cinar/checker/v2"
+)
+
+func TestTrimRight(t *testing.T) {
+	input := "    test    "
+	expected := "    test"
+
+	actual, err := v2.TrimRight(input)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if actual != expected {
+		t.Fatalf("actual %s expected %s", actual, expected)
+	}
+}
+
+func TestReflectTrimRight(t *testing.T) {
+	type Person struct {
+		Name string `checkers:"trim-right"`
+	}
+
+	person := &Person{
+		Name: "    test    ",
+	}
+
+	expected := "    test"
+
+	errs, ok := v2.CheckStruct(person)
+	if !ok {
+		t.Fatalf("got unexpected errors %v", errs)
+	}
+
+	if person.Name != expected {
+		t.Fatalf("actual %s expected %s", person.Name, expected)
+	}
+}