Add upper and lower normalizers and tests to v2. (#146)

# Describe Request

Add upper and lower normalizers and tests to v2.

# Change Type

New code.

v2/lower.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 (
+	// nameLower is the name of the lower normalizer.
+	nameLower = "lower"
+)
+
+// Lower maps all Unicode letters in the given value to their lower case.
+func Lower(value string) (string, error) {
+	return strings.ToLower(value), nil
+}
+
+// reflectLower maps all Unicode letters in the given value to their lower case.
+func reflectLower(value reflect.Value) (reflect.Value, error) {
+	newValue, err := Lower(value.Interface().(string))
+	return reflect.ValueOf(newValue), err
+}
+
+// makeLower returns the lower normalizer function.
+func makeLower(_ string) CheckFunc[reflect.Value] {
+	return reflectLower
+}

v2/lower_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 TestLower(t *testing.T) {
+	input := "CHECKER"
+	expected := "checker"
+
+	actual, err := v2.Lower(input)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if actual != expected {
+		t.Fatalf("actual %s expected %s", actual, expected)
+	}
+}
+
+func TestReflectLower(t *testing.T) {
+	type Person struct {
+		Name string `checkers:"lower"`
+	}
+
+	person := &Person{
+		Name: "CHECKER",
+	}
+
+	expected := "checker"
+
+	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/maker.go

@@ -22,13 +22,14 @@ var makers = map[string]MakeCheckFunc{
 	nameCreditCard:   makeCreditCard,
 	nameDigits:       makeDigits,
 	nameEmail:        makeEmail,
+	nameFQDN:         makeFQDN,
 	nameHTMLEscape:   makeHTMLEscape,
 	nameHTMLUnescape: makeHTMLUnescape,
-	nameFQDN:         makeFQDN,
 	nameIP:           makeIP,
 	nameIPv4:         makeIPv4,
 	nameIPv6:         makeIPv6,
 	nameISBN:         makeISBN,
+	nameLower:        makeLower,
 	nameLUHN:         makeLUHN,
 	nameMAC:          makeMAC,
 	nameMaxLen:       makeMaxLen,
@@ -37,6 +38,7 @@ var makers = map[string]MakeCheckFunc{
 	nameTrimLeft:     makeTrimLeft,
 	nameTrimRight:    makeTrimRight,
 	nameTrimSpace:    makeTrimSpace,
+	nameUpper:        makeUpper,
 	nameURL:          makeURL,
 	nameURLEscape:    makeURLEscape,
 	nameURLUnescape:  makeURLUnescape,

v2/upper.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 (
+	// nameUpper is the name of the upper normalizer.
+	nameUpper = "upper"
+)
+
+// Upper maps all Unicode letters in the given value to their upper case.
+func Upper(value string) (string, error) {
+	return strings.ToUpper(value), nil
+}
+
+// reflectUpper maps all Unicode letters in the given value to their upper case.
+func reflectUpper(value reflect.Value) (reflect.Value, error) {
+	newValue, err := Upper(value.Interface().(string))
+	return reflect.ValueOf(newValue), err
+}
+
+// makeUpper returns the upper normalizer function.
+func makeUpper(_ string) CheckFunc[reflect.Value] {
+	return reflectUpper
+}

v2/upper_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 TestUpper(t *testing.T) {
+	input := "checker"
+	expected := "CHECKER"
+
+	actual, err := v2.Upper(input)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if actual != expected {
+		t.Fatalf("actual %s expected %s", actual, expected)
+	}
+}
+
+func TestReflectUpper(t *testing.T) {
+	type Person struct {
+		Name string `checkers:"upper"`
+	}
+
+	person := &Person{
+		Name: "checker",
+	}
+
+	expected := "CHECKER"
+
+	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)
+	}
+}