fix(ir): add support for byte format in string validation

gen/_template/validators.tmpl

@@ -87,6 +87,7 @@
 			MaxLength:      {{ $v.MaxLength }},
 			MaxLengthSet:   {{ $v.MaxLengthSet }},
 			Email:          {{ $v.Email }},
+			Byte:           {{ $v.Byte }},
 			Hostname:       {{ $v.Hostname }},
 			{{- if $v.Regex }}
 			Regex:          regexMap[{{ quote $v.Regex }}],

gen/ir/validation.go

@@ -40,6 +40,9 @@ func (v *Validators) SetString(schema *jsonschema.Schema) (err error) {
 	if schema.Format == "hostname" {
 		v.String.Hostname = true
 	}
+	if schema.Format == "byte" {
+		v.String.Byte = true
+	}
 	return nil
 }
 

validate/string.go

@@ -15,6 +15,7 @@ type String struct {
 	MaxLength    int
 	MaxLengthSet bool
 	Email        bool
+	Byte         bool
 	Regex        ogenregex.Regexp
 	Hostname     bool
 }
@@ -100,12 +101,16 @@ func (t String) checkEmail(v string) error {
 
 // Validate returns error if v does not match validation rules.
 func (t String) Validate(v string) error {
+	length := len([]rune(v))
+	if t.Byte {
+		length = len([]byte(v))
+	}
 	if err := (Array{
 		MinLength:    t.MinLength,
 		MinLengthSet: t.MinLengthSet,
 		MaxLength:    t.MaxLength,
 		MaxLengthSet: t.MaxLengthSet,
-	}).ValidateLength(len([]rune(v))); err != nil {
+	}).ValidateLength(length); err != nil {
 		return err
 	}
 	if t.Email {

validate/string_test.go

@@ -61,6 +61,29 @@ func TestHostname(t *testing.T) {
 	}
 }
 
+func TestByte(t *testing.T) {
+	v := String{Byte: true}
+	v.SetMinLength(2)
+	v.SetMaxLength(5)
+	require.True(t, v.Set())
+
+	for _, b := range [][]byte{
+		[]byte("12"),
+		[]byte("abcde"),
+		[]byte("α"), // equals []byte{0xCE, 0xB1}
+	} {
+		require.NoError(t, v.Validate(string(b)))
+	}
+	for _, b := range [][]byte{
+		[]byte("1"),
+		[]byte("abcdef"),
+		[]byte(""),
+		[]byte("αβγ"), // equals []byte{0xCE, 0xB1, 0xCE, 0xB2, 0xCE, 0xB3}
+	} {
+		require.Error(t, v.Validate(string(b)), "%q should be invalid", b)
+	}
+}
+
 func TestRegex(t *testing.T) {
 	v := String{Regex: ogenregex.MustCompile(`^\d$`)}
 	require.True(t, v.Set())