Add URL escape normalizer and tests to v2. (#142)

# Describe Request

Add URL escape normalizer and tests to v2.

# Change Type

New code.

v2/maker.go

@@ -34,6 +34,7 @@ var makers = map[string]MakeCheckFunc{
 	nameRequired:     makeRequired,
 	nameTrimSpace:    makeTrimSpace,
 	nameURL:          makeURL,
+	nameURLEscape:    makeURLEscape,
 }
 
 // makeChecks take a checker config and returns the check functions.

v2/url_escape.go

@@ -0,0 +1,37 @@
+// 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 (
+	"net/url"
+	"reflect"
+)
+
+const (
+	// nameURLEscape is the name of the URL escape normalizer.
+	nameURLEscape = "url-escape"
+)
+
+// normalizeURLEscape applies URL escaping to special characters.
+// Uses net.url.QueryEscape for the actual escape operation.
+func normalizeURLEscape(value string) (string, error) {
+	return url.QueryEscape(value), nil
+}
+
+// checkURLEscape checks if the value is a valid URL escape string.
+func checkURLEscape(value reflect.Value) (reflect.Value, error) {
+	escaped, err := normalizeURLEscape(value.Interface().(string))
+	if err != nil {
+		return value, err
+	}
+	value.SetString(escaped)
+	return value, nil
+}
+
+// makeURLEscape makes a normalizer function for the URL escape normalizer.
+func makeURLEscape(_ string) CheckFunc[reflect.Value] {
+	return checkURLEscape
+}

v2/url_escape_test.go

@@ -0,0 +1,43 @@
+// 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 TestNormalizeURLEscapeNonString(t *testing.T) {
+	defer FailIfNoPanic(t, "expected panic")
+
+	type Request struct {
+		Query int `checkers:"url-escape"`
+	}
+
+	request := &Request{}
+
+	v2.CheckStruct(request)
+}
+
+func TestNormalizeURLEscape(t *testing.T) {
+	type Request struct {
+		Query string `checkers:"url-escape"`
+	}
+
+	request := &Request{
+		Query: "param1/param2 = 1 + 2 & 3 + 4",
+	}
+
+	_, valid := v2.CheckStruct(request)
+	if !valid {
+		t.Fail()
+	}
+
+	if request.Query != "param1%2Fparam2+%3D+1+%2B+2+%26+3+%2B+4" {
+		t.Fail()
+	}
+}