fix(v2): preserve nested struct JSON structure for embedded types with json tags

When a Go struct has anonymous embedded struct fields with explicit json
tags (e.g., `TimeLimitDef `json:"timeLimitDef"``), Go's encoding/json
marshals them as nested objects. However, the TS binding generator
unconditionally flattened these fields, producing incorrect TypeScript
that couldn't deserialize the JSON.

Fix deepFields() in typescriptify to check for json tags on anonymous
fields before flattening. Fix AddStructToGenerateTS() in binding.go to
register embedded struct types with json tags for separate TS class
generation.

Fixes #4117

Author: Wails Documentation Agent

v2/internal/binding/binding.go

@@ -271,9 +271,19 @@ func (b *Bindings) AddStructToGenerateTS(packageName string, structName string,
 
 	for i := 0; i < structType.NumField(); i++ {
 		field := structType.Field(i)
-		if field.Anonymous || !field.IsExported() {
+		if !field.IsExported() {
 			continue
 		}
+		if field.Anonymous {
+			jsonTag, hasTag := field.Tag.Lookup("json")
+			if !hasTag {
+				continue
+			}
+			jsonTagParts := strings.Split(jsonTag, ",")
+			if jsonTagParts[0] == "" || jsonTagParts[0] == "-" {
+				continue
+			}
+		}
 		kind := field.Type.Kind()
 		if kind == reflect.Struct {
 			fqname := field.Type.String()

v2/internal/binding/binding_test/binding_embedded_named_struct_jsontag_test.go

@@ -0,0 +1,104 @@
+package binding_test
+
+type EmbeddedWithJSONTagTimeLimitDef struct {
+	IsInfinite bool  `json:"isInfinite"`
+	StartTime  int64 `json:"startTime"`
+	EndTime    int64 `json:"endTime"`
+}
+
+type EmbeddedWithJSONTagApplication struct {
+	AppName    string `json:"appName"`
+	AppVersion string `json:"appVersion"`
+	AuthUser   string `json:"authUser"`
+	AuthModule string `json:"authModule"`
+}
+
+type StructWithEmbeddedNamedStructJSONTag struct {
+	Name                            string `json:"name"`
+	Typ                             string `json:"typ"`
+	Desc                            string `json:"desc"`
+	EmbeddedWithJSONTagTimeLimitDef `json:"timeLimitDef"`
+	EmbeddedWithJSONTagApplication  `json:"application"`
+}
+
+func (s StructWithEmbeddedNamedStructJSONTag) Get() StructWithEmbeddedNamedStructJSONTag {
+	return s
+}
+
+var EmbeddedNamedStructJSONTagTest = BindingTest{
+	name: "EmbeddedNamedStructJSONTag",
+	structs: []interface{}{
+		&StructWithEmbeddedNamedStructJSONTag{},
+	},
+	exemptions:  nil,
+	shouldError: false,
+	want: `
+export namespace binding_test {
+	export class EmbeddedWithJSONTagApplication {
+		appName: string;
+		appVersion: string;
+		authUser: string;
+		authModule: string;
+		static createFrom(source: any = {}) {
+			return new EmbeddedWithJSONTagApplication(source);
+		}
+		constructor(source: any = {}) {
+			if ('string' === typeof source) source = JSON.parse(source);
+			this.appName = source["appName"];
+			this.appVersion = source["appVersion"];
+			this.authUser = source["authUser"];
+			this.authModule = source["authModule"];
+		}
+	}
+	export class EmbeddedWithJSONTagTimeLimitDef {
+		isInfinite: boolean;
+		startTime: number;
+		endTime: number;
+		static createFrom(source: any = {}) {
+			return new EmbeddedWithJSONTagTimeLimitDef(source);
+		}
+		constructor(source: any = {}) {
+			if ('string' === typeof source) source = JSON.parse(source);
+			this.isInfinite = source["isInfinite"];
+			this.startTime = source["startTime"];
+			this.endTime = source["endTime"];
+		}
+	}
+	export class StructWithEmbeddedNamedStructJSONTag {
+		name: string;
+		typ: string;
+		desc: string;
+		timeLimitDef: EmbeddedWithJSONTagTimeLimitDef;
+		application: EmbeddedWithJSONTagApplication;
+		static createFrom(source: any = {}) {
+			return new StructWithEmbeddedNamedStructJSONTag(source);
+		}
+		constructor(source: any = {}) {
+			if ('string' === typeof source) source = JSON.parse(source);
+			this.name = source["name"];
+			this.typ = source["typ"];
+			this.desc = source["desc"];
+			this.timeLimitDef = this.convertValues(source["timeLimitDef"], EmbeddedWithJSONTagTimeLimitDef);
+			this.application = this.convertValues(source["application"], EmbeddedWithJSONTagApplication);
+		}
+		convertValues(a: any, classs: any, asMap: boolean = false): any {
+			if (!a) {
+				return a;
+			}
+			if (a.slice && a.map) {
+				return (a as any[]).map(elem => this.convertValues(elem, classs));
+			} else if ("object" === typeof a) {
+				if (asMap) {
+					for (const key of Object.keys(a)) {
+						a[key] = new classs(a[key]);
+					}
+					return a;
+				}
+				return new classs(a);
+			}
+			return a;
+		}
+	}
+}
+`,
+}

v2/internal/binding/binding_test/binding_test.go

@@ -46,6 +46,7 @@ func TestBindings_GenerateModels(t *testing.T) {
 		GeneratedJsEntityWithNestedStructInterfacesTest,
 		AnonymousSubStructTest,
 		AnonymousSubStructMultiLevelTest,
+		EmbeddedNamedStructJSONTagTest,
 		GeneratedJsEntityWithNestedStructTest,
 		EntityWithDiffNamespacesTest,
 		SpecialCharacterFieldTest,

v2/internal/typescriptify/typescriptify.go

@@ -171,13 +171,24 @@ func (t *TypeScriptify) deepFields(typeOf reflect.Type) []reflect.StructField {
 		kind := f.Type.Kind()
 		isPointer := kind == reflect.Ptr && f.Type.Elem().Kind() == reflect.Struct
 		if f.Anonymous && kind == reflect.Struct {
-			// fmt.Println(v.Interface())
-			fields = append(fields, t.deepFields(f.Type)...)
+			if jsonTag, hasTag := f.Tag.Lookup("json"); hasTag {
+				jsonTagParts := strings.Split(jsonTag, ",")
+				if jsonTagParts[0] != "" && jsonTagParts[0] != "-" {
+					fields = append(fields, f)
+				}
+			} else {
+				fields = append(fields, t.deepFields(f.Type)...)
+			}
 		} else if f.Anonymous && isPointer {
-			// fmt.Println(v.Interface())
-			fields = append(fields, t.deepFields(f.Type.Elem())...)
+			if jsonTag, hasTag := f.Tag.Lookup("json"); hasTag {
+				jsonTagParts := strings.Split(jsonTag, ",")
+				if jsonTagParts[0] != "" && jsonTagParts[0] != "-" {
+					fields = append(fields, f)
+				}
+			} else {
+				fields = append(fields, t.deepFields(f.Type.Elem())...)
+			}
 		} else {
-			// Check we have a json tag
 			jsonTag := t.getJSONFieldName(f, isPointer)
 			if jsonTag != "" {
 				fields = append(fields, f)