fix: Add pointer support for url query params (#3659) (#3666)

The pointer support in url query params (using []*Struct for binding query params) was previously available in Gin, but was removed in commit 0d50ce8 since there wasn't a test case for such a scenario, and so the case block was removed as a redundant one.

binding/form_mapping.go

@@ -239,6 +239,11 @@ func setWithProperType(val string, value reflect.Value, field reflect.StructFiel
 		return json.Unmarshal(bytesconv.StringToBytes(val), value.Addr().Interface())
 	case reflect.Map:
 		return json.Unmarshal(bytesconv.StringToBytes(val), value.Addr().Interface())
+	case reflect.Ptr:
+		if !value.Elem().IsValid() {
+			value.Set(reflect.New(value.Type().Elem()))
+		}
+		return setWithProperType(val, value.Elem(), field)
 	default:
 		return errUnknownType
 	}

binding/form_mapping_test.go

@@ -269,6 +269,39 @@ func TestMappingStructField(t *testing.T) {
 	assert.Equal(t, 9, s.J.I)
 }
 
+func TestMappingPtrField(t *testing.T) {
+	type ptrStruct struct {
+		Key int64 `json:"key"`
+	}
+
+	type ptrRequest struct {
+		Items []*ptrStruct `json:"items" form:"items"`
+	}
+
+	var err error
+
+	// With 0 items.
+	var req0 ptrRequest
+	err = mappingByPtr(&req0, formSource{}, "form")
+	assert.NoError(t, err)
+	assert.Empty(t, req0.Items)
+
+	// With 1 item.
+	var req1 ptrRequest
+	err = mappingByPtr(&req1, formSource{"items": {`{"key": 1}`}}, "form")
+	assert.NoError(t, err)
+	assert.Len(t, req1.Items, 1)
+	assert.EqualValues(t, 1, req1.Items[0].Key)
+
+	// With 2 items.
+	var req2 ptrRequest
+	err = mappingByPtr(&req2, formSource{"items": {`{"key": 1}`, `{"key": 2}`}}, "form")
+	assert.NoError(t, err)
+	assert.Len(t, req2.Items, 2)
+	assert.EqualValues(t, 1, req2.Items[0].Key)
+	assert.EqualValues(t, 2, req2.Items[1].Key)
+}
+
 func TestMappingMapField(t *testing.T) {
 	var s struct {
 		M map[string]int

gin.go

@@ -334,7 +334,6 @@ func (engine *Engine) addRoute(method, path string, handlers HandlersChain) {
 	}
 	root.addRoute(path, handlers)
 
-	// Update maxParams
 	if paramsCount := countParams(path); paramsCount > engine.maxParams {
 		engine.maxParams = paramsCount
 	}

go.mod

@@ -5,7 +5,7 @@ go 1.20
 require (
 	github.com/bytedance/sonic v1.9.1
 	github.com/gin-contrib/sse v0.1.0
-	github.com/go-playground/validator/v10 v10.15.1
+	github.com/go-playground/validator/v10 v10.16.0
 	github.com/goccy/go-json v0.10.2
 	github.com/json-iterator/go v1.1.12
 	github.com/mattn/go-isatty v0.0.19

go.sum

@@ -16,8 +16,8 @@ github.com/go-playground/locales v0.14.1 h1:EWaQ/wswjilfKLTECiXz7Rh+3BjFhfDFKv/o
 github.com/go-playground/locales v0.14.1/go.mod h1:hxrqLVvrK65+Rwrd5Fc6F2O76J/NuW9t0sjnWqG1slY=
 github.com/go-playground/universal-translator v0.18.1 h1:Bcnm0ZwsGyWbCzImXv+pAJnYK9S473LQFuzCbDbfSFY=
 github.com/go-playground/universal-translator v0.18.1/go.mod h1:xekY+UJKNuX9WP91TpwSH2VMlDf28Uj24BCp08ZFTUY=
-github.com/go-playground/validator/v10 v10.15.1 h1:BSe8uhN+xQ4r5guV/ywQI4gO59C2raYcGffYWZEjZzM=
-github.com/go-playground/validator/v10 v10.15.1/go.mod h1:9iXMNT7sEkjXb0I+enO7QXmzG6QCsPWY4zveKFVRSyU=
+github.com/go-playground/validator/v10 v10.16.0 h1:x+plE831WK4vaKHO/jpgUGsvLKIqRRkz6M78GuJAfGE=
+github.com/go-playground/validator/v10 v10.16.0/go.mod h1:9iXMNT7sEkjXb0I+enO7QXmzG6QCsPWY4zveKFVRSyU=
 github.com/goccy/go-json v0.10.2 h1:CrxCmQqYDkv1z7lO7Wbh2HN93uovUHgrECaO5ZrCXAU=
 github.com/goccy/go-json v0.10.2/go.mod h1:6MelG93GURQebXPDq3khkgXZkazVtN9CRI+MGFi0w8I=
 github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=