Add HTML escape normalizer and tests to v2. (#144)

# Describe Request

Add HTML escape normalizer and tests to v2.

# Change Type

New code.

v2/html_escape.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 (
+	"html"
+	"reflect"
+)
+
+const (
+	// nameHTMLEscape is the name of the HTML escape normalizer.
+	nameHTMLEscape = "html-escape"
+)
+
+// HTMLEscape applies HTML escaping to special characters.
+func HTMLEscape(value string) (string, error) {
+	return html.EscapeString(value), nil
+}
+
+// reflectHTMLEscape applies HTML escaping to special characters.
+func reflectHTMLEscape(value reflect.Value) (reflect.Value, error) {
+	newValue, err := HTMLEscape(value.Interface().(string))
+	return reflect.ValueOf(newValue), err
+}
+
+// makeHTMLEscape returns the HTML escape normalizer function.
+func makeHTMLEscape(_ string) CheckFunc[reflect.Value] {
+	return reflectHTMLEscape
+}

v2/html_escape_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 TestHTMLEscape(t *testing.T) {
+	input := "<tag> \"Checker\" & 'Library' </tag>"
+	expected := "&lt;tag&gt; &#34;Checker&#34; &amp; &#39;Library&#39; &lt;/tag&gt;"
+
+	actual, err := v2.HTMLEscape(input)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if actual != expected {
+		t.Fatalf("actual %s expected %s", actual, expected)
+	}
+}
+
+func TestReflectHTMLEscape(t *testing.T) {
+	type Comment struct {
+		Body string `checkers:"html-escape"`
+	}
+
+	comment := &Comment{
+		Body: "<tag> \"Checker\" & 'Library' </tag>",
+	}
+
+	expected := "&lt;tag&gt; &#34;Checker&#34; &amp; &#39;Library&#39; &lt;/tag&gt;"
+
+	errs, ok := v2.CheckStruct(comment)
+	if !ok {
+		t.Fatalf("got unexpected errors %v", errs)
+	}
+
+	if comment.Body != expected {
+		t.Fatalf("actual %s expected %s", comment.Body, expected)
+	}
+}

v2/html_unescape.go

@@ -0,0 +1,30 @@
+// 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 (
+	"html"
+	"reflect"
+)
+
+// nameHTMLUnescape is the name of the HTML unescape normalizer.
+const nameHTMLUnescape = "html-unescape"
+
+// HTMLUnescape applies HTML unescaping to special characters.
+func HTMLUnescape(value string) (string, error) {
+	return html.UnescapeString(value), nil
+}
+
+// reflectHTMLUnescape applies HTML unescaping to special characters.
+func reflectHTMLUnescape(value reflect.Value) (reflect.Value, error) {
+	newValue, err := HTMLUnescape(value.Interface().(string))
+	return reflect.ValueOf(newValue), err
+}
+
+// makeHTMLUnescape returns the HTML unescape normalizer function.
+func makeHTMLUnescape(_ string) CheckFunc[reflect.Value] {
+	return reflectHTMLUnescape
+}

v2/html_unescape_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 TestHTMLUnescape(t *testing.T) {
+	input := "<tag> "Checker" & 'Library' </tag>"
+	expected := "<tag> \"Checker\" & 'Library' </tag>"
+
+	actual, err := v2.HTMLUnescape(input)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if actual != expected {
+		t.Fatalf("actual %s expected %s", actual, expected)
+	}
+}
+
+func TestReflectHTMLUnescape(t *testing.T) {
+	type Comment struct {
+		Body string `checkers:"html-unescape"`
+	}
+
+	comment := &Comment{
+		Body: "&lt;tag&gt; &#34;Checker&#34; &amp; &#39;Library&#39; &lt;/tag&gt;",
+	}
+
+	expected := "<tag> \"Checker\" & 'Library' </tag>"
+
+	errs, ok := v2.CheckStruct(comment)
+	if !ok {
+		t.Fatalf("got unexpected errors %v", errs)
+	}
+
+	if comment.Body != expected {
+		t.Fatalf("actual %s expected %s", comment.Body, expected)
+	}
+}

v2/maker.go

@@ -22,6 +22,8 @@ var makers = map[string]MakeCheckFunc{
 	nameCreditCard:   makeCreditCard,
 	nameDigits:       makeDigits,
 	nameEmail:        makeEmail,
+	nameHTMLEscape:   makeHTMLEscape,
+	nameHTMLUnescape: makeHTMLUnescape,
 	nameFQDN:         makeFQDN,
 	nameIP:           makeIP,
 	nameIPv4:         makeIPv4,