feat: support form array in three notations (#4498)

Signed-off-by: kevin <wanjunfeng@gmail.com>

core/mapping/unmarshaler.go

@@ -18,6 +18,7 @@ import (
 )
 
 const (
+	comma            = ","
 	defaultKeyName   = "key"
 	delimiter        = '.'
 	ignoreKey        = "-"
@@ -36,6 +37,7 @@ var (
 	defaultCacheLock    sync.Mutex
 	emptyMap            = map[string]any{}
 	emptyValue          = reflect.ValueOf(lang.Placeholder)
+	stringSliceType     = reflect.TypeOf([]string{})
 )
 
 type (
@@ -80,40 +82,11 @@ func (u *Unmarshaler) Unmarshal(i, v any) error {
 	return u.unmarshal(i, v, "")
 }
 
-func (u *Unmarshaler) unmarshal(i, v any, fullName string) error {
-	valueType := reflect.TypeOf(v)
-	if valueType.Kind() != reflect.Ptr {
-		return errValueNotSettable
-	}
-
-	elemType := Deref(valueType)
-	switch iv := i.(type) {
-	case map[string]any:
-		if elemType.Kind() != reflect.Struct {
-			return errTypeMismatch
-		}
-
-		return u.unmarshalValuer(mapValuer(iv), v, fullName)
-	case []any:
-		if elemType.Kind() != reflect.Slice {
-			return errTypeMismatch
-		}
-
-		return u.fillSlice(elemType, reflect.ValueOf(v).Elem(), iv, fullName)
-	default:
-		return errUnsupportedType
-	}
-}
-
 // UnmarshalValuer unmarshals m into v.
 func (u *Unmarshaler) UnmarshalValuer(m Valuer, v any) error {
 	return u.unmarshalValuer(simpleValuer{current: m}, v, "")
 }
 
-func (u *Unmarshaler) unmarshalValuer(m Valuer, v any, fullName string) error {
-	return u.unmarshalWithFullName(simpleValuer{current: m}, v, fullName)
-}
-
 func (u *Unmarshaler) fillMap(fieldType reflect.Type, value reflect.Value,
 	mapValue any, fullName string) error {
 	if !value.CanSet() {
@@ -173,13 +146,18 @@ func (u *Unmarshaler) fillSlice(fieldType reflect.Type, value reflect.Value,
 	baseType := fieldType.Elem()
 	dereffedBaseType := Deref(baseType)
 	dereffedBaseKind := dereffedBaseType.Kind()
-	conv := reflect.MakeSlice(reflect.SliceOf(baseType), refValue.Len(), refValue.Cap())
 	if refValue.Len() == 0 {
-		value.Set(conv)
+		value.Set(reflect.MakeSlice(reflect.SliceOf(baseType), 0, 0))
 		return nil
 	}
 
+	if u.opts.fromArray {
+		refValue = makeStringSlice(refValue)
+	}
+
 	var valid bool
+	conv := reflect.MakeSlice(reflect.SliceOf(baseType), refValue.Len(), refValue.Cap())
+
 	for i := 0; i < refValue.Len(); i++ {
 		ithValue := refValue.Index(i).Interface()
 		if ithValue == nil {
@@ -191,17 +169,9 @@ func (u *Unmarshaler) fillSlice(fieldType reflect.Type, value reflect.Value,
 
 		switch dereffedBaseKind {
 		case reflect.Struct:
-			target := reflect.New(dereffedBaseType)
-			val, ok := ithValue.(map[string]any)
-			if !ok {
-				return errTypeMismatch
-			}
-
-			if err := u.unmarshal(val, target.Interface(), sliceFullName); err != nil {
+			if err := u.fillStructElement(baseType, conv.Index(i), ithValue, sliceFullName); err != nil {
 				return err
 			}
-
-			SetValue(fieldType.Elem(), conv.Index(i), target.Elem())
 		case reflect.Slice:
 			if err := u.fillSlice(dereffedBaseType, conv.Index(i), ithValue, sliceFullName); err != nil {
 				return err
@@ -236,7 +206,7 @@ func (u *Unmarshaler) fillSliceFromString(fieldType reflect.Type, value reflect.
 		return errUnsupportedType
 	}
 
-	baseFieldType := Deref(fieldType.Elem())
+	baseFieldType := fieldType.Elem()
 	baseFieldKind := baseFieldType.Kind()
 	conv := reflect.MakeSlice(reflect.SliceOf(baseFieldType), len(slice), cap(slice))
 
@@ -257,29 +227,39 @@ func (u *Unmarshaler) fillSliceValue(slice reflect.Value, index int,
 	}
 
 	ithVal := slice.Index(index)
+	ithValType := ithVal.Type()
+
 	switch v := value.(type) {
 	case fmt.Stringer:
 		return setValueFromString(baseKind, ithVal, v.String())
 	case string:
 		return setValueFromString(baseKind, ithVal, v)
 	case map[string]any:
-		return u.fillMap(ithVal.Type(), ithVal, value, fullName)
+		// deref to handle both pointer and non-pointer types.
+		switch Deref(ithValType).Kind() {
+		case reflect.Struct:
+			return u.fillStructElement(ithValType, ithVal, v, fullName)
+		case reflect.Map:
+			return u.fillMap(ithValType, ithVal, value, fullName)
+		default:
+			return errTypeMismatch
+		}
 	default:
 		// don't need to consider the difference between int, int8, int16, int32, int64,
 		// uint, uint8, uint16, uint32, uint64, because they're handled as json.Number.
 		if ithVal.Kind() == reflect.Ptr {
-			baseType := Deref(ithVal.Type())
+			baseType := Deref(ithValType)
 			if !reflect.TypeOf(value).AssignableTo(baseType) {
 				return errTypeMismatch
 			}
 
 			target := reflect.New(baseType).Elem()
 			target.Set(reflect.ValueOf(value))
-			SetValue(ithVal.Type(), ithVal, target)
+			SetValue(ithValType, ithVal, target)
 			return nil
 		}
 
-		if !reflect.TypeOf(value).AssignableTo(ithVal.Type()) {
+		if !reflect.TypeOf(value).AssignableTo(ithValType) {
 			return errTypeMismatch
 		}
 
@@ -310,6 +290,23 @@ func (u *Unmarshaler) fillSliceWithDefault(derefedType reflect.Type, value refle
 	return u.fillSlice(derefedType, value, slice, fullName)
 }
 
+func (u *Unmarshaler) fillStructElement(baseType reflect.Type, target reflect.Value,
+	value any, fullName string) error {
+	val, ok := value.(map[string]any)
+	if !ok {
+		return errTypeMismatch
+	}
+
+	// use Deref(baseType) to get the base type in case the type is a pointer type.
+	ptr := reflect.New(Deref(baseType))
+	if err := u.unmarshal(val, ptr.Interface(), fullName); err != nil {
+		return err
+	}
+
+	SetValue(baseType, target, ptr.Elem())
+	return nil
+}
+
 func (u *Unmarshaler) fillUnmarshalerStruct(fieldType reflect.Type,
 	value reflect.Value, targetValue string) error {
 	if !value.CanSet() {
@@ -952,6 +949,35 @@ func (u *Unmarshaler) processNamedFieldWithoutValue(fieldType reflect.Type, valu
 	return nil
 }
 
+func (u *Unmarshaler) unmarshal(i, v any, fullName string) error {
+	valueType := reflect.TypeOf(v)
+	if valueType.Kind() != reflect.Ptr {
+		return errValueNotSettable
+	}
+
+	elemType := Deref(valueType)
+	switch iv := i.(type) {
+	case map[string]any:
+		if elemType.Kind() != reflect.Struct {
+			return errTypeMismatch
+		}
+
+		return u.unmarshalValuer(mapValuer(iv), v, fullName)
+	case []any:
+		if elemType.Kind() != reflect.Slice {
+			return errTypeMismatch
+		}
+
+		return u.fillSlice(elemType, reflect.ValueOf(v).Elem(), iv, fullName)
+	default:
+		return errUnsupportedType
+	}
+}
+
+func (u *Unmarshaler) unmarshalValuer(m Valuer, v any, fullName string) error {
+	return u.unmarshalWithFullName(simpleValuer{current: m}, v, fullName)
+}
+
 func (u *Unmarshaler) unmarshalWithFullName(m valuerWithParent, v any, fullName string) error {
 	rv := reflect.ValueOf(v)
 	if err := ValidatePtr(rv); err != nil {
@@ -1146,6 +1172,35 @@ func join(elem ...string) string {
 	return builder.String()
 }
 
+func makeStringSlice(refValue reflect.Value) reflect.Value {
+	if refValue.Len() != 1 {
+		return refValue
+	}
+
+	element := refValue.Index(0)
+	if element.Kind() != reflect.String {
+		return refValue
+	}
+
+	val, ok := element.Interface().(string)
+	if !ok {
+		return refValue
+	}
+
+	splits := strings.Split(val, comma)
+	if len(splits) <= 1 {
+		return refValue
+	}
+
+	slice := reflect.MakeSlice(stringSliceType, len(splits), len(splits))
+	for i, split := range splits {
+		// allow empty strings
+		slice.Index(i).Set(reflect.ValueOf(split))
+	}
+
+	return slice
+}
+
 func newInitError(name string) error {
 	return fmt.Errorf("field %q is not set", name)
 }

core/mapping/unmarshaler_test.go

@@ -351,7 +351,7 @@ func TestUnmarshalIntSliceOfPtr(t *testing.T) {
 		assert.Error(t, UnmarshalKey(m, &in))
 	})
 
-	t.Run("int slice with nil", func(t *testing.T) {
+	t.Run("int slice with nil element", func(t *testing.T) {
 		type inner struct {
 			Ints []int `key:"ints"`
 		}
@@ -365,6 +365,21 @@ func TestUnmarshalIntSliceOfPtr(t *testing.T) {
 			assert.Empty(t, in.Ints)
 		}
 	})
+
+	t.Run("int slice with nil", func(t *testing.T) {
+		type inner struct {
+			Ints []int `key:"ints"`
+		}
+
+		m := map[string]any{
+			"ints": []any(nil),
+		}
+
+		var in inner
+		if assert.NoError(t, UnmarshalKey(m, &in)) {
+			assert.Empty(t, in.Ints)
+		}
+	})
 }
 
 func TestUnmarshalIntWithDefault(t *testing.T) {
@@ -1374,20 +1389,82 @@ func TestUnmarshalWithFloatPtr(t *testing.T) {
 }
 
 func TestUnmarshalIntSlice(t *testing.T) {
-	var v struct {
-		Ages  []int `key:"ages"`
-		Slice []int `key:"slice"`
-	}
-	m := map[string]any{
-		"ages":  []int{1, 2},
-		"slice": []any{},
-	}
+	t.Run("int slice from int", func(t *testing.T) {
+		var v struct {
+			Ages  []int `key:"ages"`
+			Slice []int `key:"slice"`
+		}
+		m := map[string]any{
+			"ages":  []int{1, 2},
+			"slice": []any{},
+		}
 
-	ast := assert.New(t)
-	if ast.NoError(UnmarshalKey(m, &v)) {
-		ast.ElementsMatch([]int{1, 2}, v.Ages)
-		ast.Equal([]int{}, v.Slice)
-	}
+		ast := assert.New(t)
+		if ast.NoError(UnmarshalKey(m, &v)) {
+			ast.ElementsMatch([]int{1, 2}, v.Ages)
+			ast.Equal([]int{}, v.Slice)
+		}
+	})
+
+	t.Run("int slice from one int", func(t *testing.T) {
+		var v struct {
+			Ages []int `key:"ages"`
+		}
+		m := map[string]any{
+			"ages": []int{2},
+		}
+
+		ast := assert.New(t)
+		unmarshaler := NewUnmarshaler(defaultKeyName, WithFromArray())
+		if ast.NoError(unmarshaler.Unmarshal(m, &v)) {
+			ast.ElementsMatch([]int{2}, v.Ages)
+		}
+	})
+
+	t.Run("int slice from one int string", func(t *testing.T) {
+		var v struct {
+			Ages []int `key:"ages"`
+		}
+		m := map[string]any{
+			"ages": []string{"2"},
+		}
+
+		ast := assert.New(t)
+		unmarshaler := NewUnmarshaler(defaultKeyName, WithFromArray())
+		if ast.NoError(unmarshaler.Unmarshal(m, &v)) {
+			ast.ElementsMatch([]int{2}, v.Ages)
+		}
+	})
+
+	t.Run("int slice from one json.Number", func(t *testing.T) {
+		var v struct {
+			Ages []int `key:"ages"`
+		}
+		m := map[string]any{
+			"ages": []json.Number{"2"},
+		}
+
+		ast := assert.New(t)
+		unmarshaler := NewUnmarshaler(defaultKeyName, WithFromArray())
+		if ast.NoError(unmarshaler.Unmarshal(m, &v)) {
+			ast.ElementsMatch([]int{2}, v.Ages)
+		}
+	})
+
+	t.Run("int slice from one int strings", func(t *testing.T) {
+		var v struct {
+			Ages []int `key:"ages"`
+		}
+		m := map[string]any{
+			"ages": []string{"1,2"},
+		}
+
+		ast := assert.New(t)
+		unmarshaler := NewUnmarshaler(defaultKeyName, WithFromArray())
+		if ast.NoError(unmarshaler.Unmarshal(m, &v)) {
+			ast.ElementsMatch([]int{1, 2}, v.Ages)
+		}
+	})
 }
 
 func TestUnmarshalString(t *testing.T) {
@@ -1442,6 +1519,36 @@ func TestUnmarshalStringSliceFromString(t *testing.T) {
 		}
 	})
 
+	t.Run("slice from empty string", func(t *testing.T) {
+		var v struct {
+			Names []string `key:"names"`
+		}
+		m := map[string]any{
+			"names": []string{""},
+		}
+
+		ast := assert.New(t)
+		unmarshaler := NewUnmarshaler(defaultKeyName, WithFromArray())
+		if ast.NoError(unmarshaler.Unmarshal(m, &v)) {
+			ast.ElementsMatch([]string{""}, v.Names)
+		}
+	})
+
+	t.Run("slice from empty and valid string", func(t *testing.T) {
+		var v struct {
+			Names []string `key:"names"`
+		}
+		m := map[string]any{
+			"names": []string{","},
+		}
+
+		ast := assert.New(t)
+		unmarshaler := NewUnmarshaler(defaultKeyName, WithFromArray())
+		if ast.NoError(unmarshaler.Unmarshal(m, &v)) {
+			ast.ElementsMatch([]string{"", ""}, v.Names)
+		}
+	})
+
 	t.Run("slice from string with slice error", func(t *testing.T) {
 		var v struct {
 			Names []int `key:"names"`
@@ -5862,6 +5969,38 @@ func TestUnmarshal_Unmarshaler(t *testing.T) {
 	})
 }
 
+func TestParseJsonStringValue(t *testing.T) {
+	t.Run("string", func(t *testing.T) {
+		type GoodsInfo struct {
+			Sku int64 `json:"sku,optional"`
+		}
+
+		type GetReq struct {
+			GoodsList []*GoodsInfo `json:"goods_list"`
+		}
+
+		input := map[string]any{"goods_list": "[{\"sku\":11},{\"sku\":22}]"}
+		var v GetReq
+		assert.NotPanics(t, func() {
+			assert.NoError(t, UnmarshalJsonMap(input, &v))
+			assert.Equal(t, 2, len(v.GoodsList))
+			assert.ElementsMatch(t, []int64{11, 22}, []int64{v.GoodsList[0].Sku, v.GoodsList[1].Sku})
+		})
+	})
+
+	t.Run("string with invalid type", func(t *testing.T) {
+		type GetReq struct {
+			GoodsList []*int `json:"goods_list"`
+		}
+
+		input := map[string]any{"goods_list": "[{\"sku\":11},{\"sku\":22}]"}
+		var v GetReq
+		assert.NotPanics(t, func() {
+			assert.Error(t, UnmarshalJsonMap(input, &v))
+		})
+	})
+}
+
 func BenchmarkDefaultValue(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		var a struct {

rest/httpx/requests_test.go

@@ -88,6 +88,36 @@ func TestParseFormArray(t *testing.T) {
 		}
 	})
 
+	t.Run("slice with empty", func(t *testing.T) {
+		var v struct {
+			Name []string `form:"name,optional"`
+		}
+
+		r, err := http.NewRequest(
+			http.MethodGet,
+			"/a",
+			http.NoBody)
+		assert.NoError(t, err)
+		if assert.NoError(t, Parse(r, &v)) {
+			assert.ElementsMatch(t, []string{}, v.Name)
+		}
+	})
+
+	t.Run("slice with empty", func(t *testing.T) {
+		var v struct {
+			Name []string `form:"name,optional"`
+		}
+
+		r, err := http.NewRequest(
+			http.MethodGet,
+			"/a?name=",
+			http.NoBody)
+		assert.NoError(t, err)
+		if assert.NoError(t, Parse(r, &v)) {
+			assert.ElementsMatch(t, []string{""}, v.Name)
+		}
+	})
+
 	t.Run("slice with empty and non-empty", func(t *testing.T) {
 		var v struct {
 			Name []string `form:"name"`
@@ -99,7 +129,67 @@ func TestParseFormArray(t *testing.T) {
 			http.NoBody)
 		assert.NoError(t, err)
 		if assert.NoError(t, Parse(r, &v)) {
-			assert.ElementsMatch(t, []string{"1"}, v.Name)
+			assert.ElementsMatch(t, []string{"", "1"}, v.Name)
+		}
+	})
+
+	t.Run("slice with one value on array format", func(t *testing.T) {
+		var v struct {
+			Names []string `form:"names"`
+		}
+
+		r, err := http.NewRequest(
+			http.MethodGet,
+			"/a?names=1,2,3",
+			http.NoBody)
+		assert.NoError(t, err)
+		if assert.NoError(t, Parse(r, &v)) {
+			assert.ElementsMatch(t, []string{"1", "2", "3"}, v.Names)
+		}
+	})
+
+	t.Run("slice with one value on combined array format", func(t *testing.T) {
+		var v struct {
+			Names []string `form:"names"`
+		}
+
+		r, err := http.NewRequest(
+			http.MethodGet,
+			"/a?names=[1,2,3]&names=4",
+			http.NoBody)
+		assert.NoError(t, err)
+		if assert.NoError(t, Parse(r, &v)) {
+			assert.ElementsMatch(t, []string{"[1,2,3]", "4"}, v.Names)
+		}
+	})
+
+	t.Run("slice with one value on integer array format", func(t *testing.T) {
+		var v struct {
+			Numbers []int `form:"numbers"`
+		}
+
+		r, err := http.NewRequest(
+			http.MethodGet,
+			"/a?numbers=1,2,3",
+			http.NoBody)
+		assert.NoError(t, err)
+		if assert.NoError(t, Parse(r, &v)) {
+			assert.ElementsMatch(t, []int{1, 2, 3}, v.Numbers)
+		}
+	})
+
+	t.Run("slice with one value on array format brackets", func(t *testing.T) {
+		var v struct {
+			Names []string `form:"names"`
+		}
+
+		r, err := http.NewRequest(
+			http.MethodGet,
+			"/a?names[]=1&names[]=2&names[]=3",
+			http.NoBody)
+		assert.NoError(t, err)
+		if assert.NoError(t, Parse(r, &v)) {
+			assert.ElementsMatch(t, []string{"1", "2", "3"}, v.Names)
 		}
 	})
 }
@@ -528,6 +618,26 @@ func TestCustomUnmarshalerStructRequest(t *testing.T) {
 	assert.Equal(t, "hello", v.Foo.Name)
 }
 
+func TestParseJsonStringRequest(t *testing.T) {
+	type GoodsInfo struct {
+		Sku int64 `json:"sku,optional"`
+	}
+
+	type GetReq struct {
+		GoodsList []*GoodsInfo `json:"goods_list"`
+	}
+
+	input := `{"goods_list":"[{\"sku\":11},{\"sku\":22}]"}`
+	r := httptest.NewRequest(http.MethodPost, "/a", strings.NewReader(input))
+	r.Header.Set(ContentType, JsonContentType)
+	var v GetReq
+	assert.NotPanics(t, func() {
+		assert.NoError(t, Parse(r, &v))
+		assert.Equal(t, 2, len(v.GoodsList))
+		assert.ElementsMatch(t, []int64{11, 22}, []int64{v.GoodsList[0].Sku, v.GoodsList[1].Sku})
+	})
+}
+
 func BenchmarkParseRaw(b *testing.B) {
 	r, err := http.NewRequest(http.MethodGet, "http://hello.com/a?name=hello&age=18&percent=3.4", http.NoBody)
 	if err != nil {

rest/httpx/util.go

@@ -2,12 +2,23 @@ package httpx
 
 import (
 	"errors"
+	"fmt"
 	"net/http"
+	"strings"
 )
 
-const xForwardedFor = "X-Forwarded-For"
+const (
+	xForwardedFor = "X-Forwarded-For"
+	arraySuffix   = "[]"
+	// most servers and clients have a limit of 8192 bytes (8 KB)
+	// one parameter at least take 4 chars, for example `?a=b&c=d`
+	maxFormParamCount = 2048
+)
 
-// GetFormValues returns the form values.
+// GetFormValues returns the form values supporting three array notation formats:
+//  1. Standard notation: /api?names=alice&names=bob
+//  2. Comma notation: /api?names=alice,bob
+//  3. Bracket notation: /api?names[]=alice&names[]=bob
 func GetFormValues(r *http.Request) (map[string]any, error) {
 	if err := r.ParseForm(); err != nil {
 		return nil, err
@@ -19,16 +30,23 @@ func GetFormValues(r *http.Request) (map[string]any, error) {
 		}
 	}
 
+	var n int
 	params := make(map[string]any, len(r.Form))
 	for name, values := range r.Form {
 		filtered := make([]string, 0, len(values))
 		for _, v := range values {
-			if len(v) > 0 {
+			if n < maxFormParamCount {
 				filtered = append(filtered, v)
+				n++
+			} else {
+				return nil, fmt.Errorf("too many form values, error: %s", r.Form.Encode())
 			}
 		}
 
 		if len(filtered) > 0 {
+			if strings.HasSuffix(name, arraySuffix) {
+				name = name[:len(name)-2]
+			}
 			params[name] = filtered
 		}
 	}

rest/httpx/util_test.go

@@ -1,7 +1,9 @@
 package httpx
 
 import (
+	"fmt"
 	"net/http"
+	"net/url"
 	"strings"
 	"testing"
 
@@ -23,3 +25,23 @@ func TestGetRemoteAddrNoHeader(t *testing.T) {
 
 	assert.True(t, len(GetRemoteAddr(r)) == 0)
 }
+
+func TestGetFormValues_TooManyValues(t *testing.T) {
+	form := url.Values{}
+
+	// Add more values than the limit
+	for i := 0; i < maxFormParamCount+10; i++ {
+		form.Add("param", fmt.Sprintf("value%d", i))
+	}
+
+	// Create a new request with the form data
+	req, err := http.NewRequest("POST", "/test", strings.NewReader(form.Encode()))
+	assert.NoError(t, err)
+
+	// Set the content type for form data
+	req.Header.Set(ContentType, "application/x-www-form-urlencoded")
+
+	_, err = GetFormValues(req)
+	assert.Error(t, err)
+	assert.Contains(t, err.Error(), "too many form values")
+}

rest/router/patrouter_test.go

@@ -516,28 +516,55 @@ func TestParsePtrInRequestEmpty(t *testing.T) {
 }
 
 func TestParseQueryOptional(t *testing.T) {
-	r, err := http.NewRequest(http.MethodGet, "http://hello.com/kevin/2017?nickname=whatever&zipcode=", nil)
-	assert.Nil(t, err)
+	t.Run("optional with string", func(t *testing.T) {
+		r, err := http.NewRequest(http.MethodGet, "http://hello.com/kevin/2017?nickname=whatever&zipcode=", nil)
+		assert.Nil(t, err)
 
-	router := NewRouter()
-	err = router.Handle(http.MethodGet, "/:name/:year", http.HandlerFunc(
-		func(w http.ResponseWriter, r *http.Request) {
-			v := struct {
-				Nickname string `form:"nickname"`
-				Zipcode  int64  `form:"zipcode,optional"`
-			}{}
+		router := NewRouter()
+		err = router.Handle(http.MethodGet, "/:name/:year", http.HandlerFunc(
+			func(w http.ResponseWriter, r *http.Request) {
+				v := struct {
+					Nickname string `form:"nickname"`
+					Zipcode  string `form:"zipcode,optional"`
+				}{}
 
-			err = httpx.Parse(r, &v)
-			assert.Nil(t, err)
-			_, err = io.WriteString(w, fmt.Sprintf("%s:%d", v.Nickname, v.Zipcode))
-			assert.Nil(t, err)
-		}))
-	assert.Nil(t, err)
+				err = httpx.Parse(r, &v)
+				assert.Nil(t, err)
+				_, err = io.WriteString(w, fmt.Sprintf("%s:%s", v.Nickname, v.Zipcode))
+				assert.Nil(t, err)
+			}))
+		assert.Nil(t, err)
 
-	rr := httptest.NewRecorder()
-	router.ServeHTTP(rr, r)
+		rr := httptest.NewRecorder()
+		router.ServeHTTP(rr, r)
 
-	assert.Equal(t, "whatever:0", rr.Body.String())
+		assert.Equal(t, "whatever:", rr.Body.String())
+	})
+
+	t.Run("optional with int", func(t *testing.T) {
+		r, err := http.NewRequest(http.MethodGet, "http://hello.com/kevin/2017?nickname=whatever", nil)
+		assert.Nil(t, err)
+
+		router := NewRouter()
+		err = router.Handle(http.MethodGet, "/:name/:year", http.HandlerFunc(
+			func(w http.ResponseWriter, r *http.Request) {
+				v := struct {
+					Nickname string `form:"nickname"`
+					Zipcode  int    `form:"zipcode,optional"`
+				}{}
+
+				err = httpx.Parse(r, &v)
+				assert.Nil(t, err)
+				_, err = io.WriteString(w, fmt.Sprintf("%s:%d", v.Nickname, v.Zipcode))
+				assert.Nil(t, err)
+			}))
+		assert.Nil(t, err)
+
+		rr := httptest.NewRecorder()
+		router.ServeHTTP(rr, r)
+
+		assert.Equal(t, "whatever:0", rr.Body.String())
+	})
 }
 
 func TestParse(t *testing.T) {