Fix #1858: Add query params binding support for anonymous struct pointer filed

Author: lipengwei

bind.go

@@ -144,11 +144,20 @@ func (b *DefaultBinder) bindData(destination interface{}, data map[string][]stri
 	for i := 0; i < typ.NumField(); i++ {
 		typeField := typ.Field(i)
 		structField := val.Field(i)
+		if typeField.Anonymous {
+			for structField.Kind() == reflect.Ptr {
+				structField = structField.Elem()
+			}
+		}
 		if !structField.CanSet() {
 			continue
 		}
 		structFieldKind := structField.Kind()
 		inputFieldName := typeField.Tag.Get(tag)
+		if typeField.Anonymous && structField.Kind() == reflect.Struct && inputFieldName != "" {
+			// if anonymous struct, ignore custom tag
+			inputFieldName = ""
+		}
 
 		if inputFieldName == "" {
 			// If tag is nil, we inspect if the field is a not BindUnmarshaler struct and try to bind data into it (might contains fields with tags).

bind_test.go

@@ -100,6 +100,9 @@ type (
 	Struct      struct {
 		Foo string
 	}
+	Bar struct {
+		Baz int `json:"baz" query:"baz"`
+	}
 )
 
 func (t *Timestamp) UnmarshalParam(src string) error {
@@ -330,6 +333,48 @@ func TestBindUnmarshalParamPtr(t *testing.T) {
 	}
 }
 
+func TestBindUnmarshalParamAnonymousFieldPtr(t *testing.T) {
+	e := New()
+	req := httptest.NewRequest(http.MethodGet, "/?baz=1", nil)
+	rec := httptest.NewRecorder()
+	c := e.NewContext(req, rec)
+	result := struct {
+		*Bar
+	}{&Bar{}}
+	err := c.Bind(&result)
+	if assert.NoError(t, err) {
+		assert.Equal(t, 1, result.Baz)
+	}
+}
+
+func TestBindUnmarshalParamAnonymousFieldPtrNil(t *testing.T) {
+	e := New()
+	req := httptest.NewRequest(http.MethodGet, "/?baz=1", nil)
+	rec := httptest.NewRecorder()
+	c := e.NewContext(req, rec)
+	result := struct {
+		*Bar
+	}{}
+	err := c.Bind(&result)
+	if assert.NoError(t, err) {
+		assert.Nil(t, result.Bar)
+	}
+}
+
+func TestBindUnmarshalParamAnonymousFieldPtrCustomTag(t *testing.T) {
+	e := New()
+	req := httptest.NewRequest(http.MethodGet, `/?bar={"baz":100}&baz=1`, nil)
+	rec := httptest.NewRecorder()
+	c := e.NewContext(req, rec)
+	result := struct {
+		*Bar `json:"bar" query:"bar"`
+	}{&Bar{}}
+	err := c.Bind(&result)
+	if assert.NoError(t, err) {
+		assert.Equal(t, 1, result.Baz)
+	}
+}
+
 func TestBindUnmarshalTextPtr(t *testing.T) {
 	e := New()
 	req := httptest.NewRequest(GET, "/?ts=2016-12-06T19:09:05Z", nil)