Fix generic components generation (#641)

* Generate generic params defaults for a component's class

* Forward generic params to the instance property

Author: IlyaKhD

packages/devextreme-react-generator/src/component-generator.test.ts

@@ -89,9 +89,9 @@ interface ICLASS_NAMEOptions<T1 = any, T2 = any> extends Properties<T1, T2>, IHt
   dataSource?: Properties<T1, T2>["dataSource"];
 }
 
-class CLASS_NAME<T1, T2> extends BaseComponent<ICLASS_NAMEOptions<T1, T2>> {
+class CLASS_NAME<T1 = any, T2 = any> extends BaseComponent<ICLASS_NAMEOptions<T1, T2>> {
 
-  public get instance(): dxCLASS_NAME {
+  public get instance(): dxCLASS_NAME<T1, T2> {
     return this._instance;
   }
 

packages/devextreme-react-generator/src/component-generator.ts

@@ -351,9 +351,9 @@ const renderComponent: (model: {
   useRequestAnimationFrameFlag?: boolean;
   typeParams: string[] | undefined;
 }) => string = createTempate(
-  `class <#= it.className #>${TYPE_PARAMS} extends BaseComponent<<#= it.optionsName #>${TYPE_PARAMS}> {
+  `class <#= it.className #>${TYPE_PARAMS_WITH_DEFAULTS} extends BaseComponent<<#= it.optionsName #>${TYPE_PARAMS}> {
 
-  public get instance(): <#= it.widgetName #> {
+  public get instance(): <#= it.widgetName #>${TYPE_PARAMS} {
     return this._instance;
   }