[GO] Add assert constraints checks for complex types in the model tem…

…plate

modules/openapi-generator/src/main/resources/go-server/helpers.mustache

@@ -32,16 +32,16 @@ func IsZeroValue(val interface{}) bool {
 	return val == nil || reflect.DeepEqual(val, reflect.Zero(reflect.TypeOf(val)).Interface())
 }
 
-// AssertRecurseInterfaceRequired recursively checks each struct in a slice against the callback.
+// AssertRecurseInterface recursively checks each struct in a slice against the callback.
 // This method traverse nested slices in a preorder fashion.
-func AssertRecurseInterfaceRequired[T any](obj interface{}, callback func(T) error) error {
-	return AssertRecurseValueRequired(reflect.ValueOf(obj), callback)
+func AssertRecurseInterface[T any](obj interface{}, callback func(T) error) error {
+	return AssertRecurseValue(reflect.ValueOf(obj), callback)
 }
 
-// AssertRecurseValueRequired checks each struct in the nested slice against the callback.
+// AssertRecurseValue checks each struct in the nested slice against the callback.
 // This method traverse nested slices in a preorder fashion. ErrTypeAssertionError is thrown if
 // the underlying struct does not match type T.
-func AssertRecurseValueRequired[T any](value reflect.Value, callback func(T) error) error {
+func AssertRecurseValue[T any](value reflect.Value, callback func(T) error) error {
 	switch value.Kind() {
 	// If it is a struct we check using callback
 	case reflect.Struct:
@@ -57,7 +57,7 @@ func AssertRecurseValueRequired[T any](value reflect.Value, callback func(T) err
 	// If it is a slice we continue recursion
 	case reflect.Slice:
 		for i := 0; i < value.Len(); i++ {
-			if err := AssertRecurseValueRequired(value.Index(i), callback); err != nil {
+			if err := AssertRecurseValue(value.Index(i), callback); err != nil {
 				return err
 			}
 		}

modules/openapi-generator/src/main/resources/go-server/model.mustache

@@ -133,7 +133,7 @@ func Assert{{classname}}Required(obj {{classname}}) error {
 		{{^items.isModel}}
 			{{#mostInnerItems.isModel}}
 				{{^mostInnerItems.isPrimitiveType}}
-{{#isNullable}}	{{/isNullable}}	if err := AssertRecurseInterfaceRequired({{#isNullable}}*{{/isNullable}}obj.{{name}}, Assert{{mostInnerItems.dataType}}Required); err != nil {
+{{#isNullable}}	{{/isNullable}}	if err := AssertRecurseInterface({{#isNullable}}*{{/isNullable}}obj.{{name}}, Assert{{mostInnerItems.dataType}}Required); err != nil {
 {{#isNullable}}	{{/isNullable}}		return err
 {{#isNullable}}	{{/isNullable}}	}
 				{{/mostInnerItems.isPrimitiveType}}
@@ -174,6 +174,61 @@ func Assert{{classname}}Constraints(obj {{classname}}) error {
 		return &ParsingError{Param: "{{name}}", Err: errors.New(errMsgMaxValueConstraint)}
 	}
 {{/maximum}}
+{{#isNullable}}
+{{#isModel}}
+    if obj.{{name}} != nil {
+{{/isModel}}
+{{#isArray}}
+{{#items.isModel}}
+    if obj.{{name}} != nil {
+{{/items.isModel}}
+{{/isArray}}
+{{/isNullable}}
+{{#isModel}}
+{{#isNullable}}     {{/isNullable}}	if err := Assert{{baseType}}Constraints({{#isNullable}}*{{/isNullable}}obj.{{name}}); err != nil {
+{{#isNullable}}     {{/isNullable}}		return err
+{{#isNullable}}     {{/isNullable}}	}
+{{/isModel}}
+{{#isArray}}
+{{#items.isModel}}
+{{#isNullable}}     {{/isNullable}}	for _, el := range {{#isNullable}}*{{/isNullable}}obj.{{name}} {
+{{#isNullable}}     {{/isNullable}}		if err := Assert{{items.baseType}}Constraints(el); err != nil {
+{{#isNullable}}     {{/isNullable}}			return err
+{{#isNullable}}     {{/isNullable}}		}
+{{#isNullable}}     {{/isNullable}}	}
+{{/items.isModel}}
+{{^items.isModel}}
+{{#mostInnerItems.isModel}}
+{{^mostInnerItems.isPrimitiveType}}
+{{#isNullable}}
+    if obj.{{name}} != nil {
+{{/isNullable}}
+{{#isNullable}}     {{/isNullable}}	if err := AssertRecurseInterface({{#isNullable}}*{{/isNullable}}obj.{{name}}, Assert{{mostInnerItems.dataType}}Constraints); err != nil {
+{{#isNullable}}     {{/isNullable}}		return err
+{{#isNullable}}     {{/isNullable}}	}
+{{/mostInnerItems.isPrimitiveType}}
+{{/mostInnerItems.isModel}}
+{{/items.isModel}}
+{{/isArray}}
+{{#isNullable}}
+{{#isModel}}
+    }
+{{/isModel}}
+{{#isArray}}
+{{#items.isModel}}
+    }
+{{/items.isModel}}
+{{^items.isModel}}
+{{#mostInnerItems.isModel}}
+{{^mostInnerItems.isPrimitiveType}}
+{{#isNullable}}
+    }
+{{/isNullable}}
+{{/mostInnerItems.isPrimitiveType}}
+{{/mostInnerItems.isModel}}
+{{/items.isModel}}
+{{/isArray}}
+{{/isNullable}}
 {{/Vars}}
 	return nil
 }{{/model}}{{/models}}