[Fabric] Create a custom component spec file

js/NativeAnswerViewer.js

@@ -0,0 +1,34 @@
+/**
+ * @format
+ * @flow strict-local
+ */
+
+import codegenNativeComponent from 'react-native/Libraries/Utilities/codegenNativeComponent';
+import codegenNativeCommands from 'react-native/Libraries/Utilities/codegenNativeCommands';
+import type {HostComponent} from 'react-native/Libraries/Renderer/shims/ReactNativeTypes';
+import type {ViewProps} from 'react-native/Libraries/Components/View/ViewPropTypes';
+import type {Int32} from 'react-native/Libraries/Types/CodegenTypes';
+import * as React from 'react';
+
+type NativeProps = $ReadOnly<{|
+  ...ViewProps,
+  color?: string,
+  step?: Int32,
+|}>;
+
+export type AnswerViewerViewType = HostComponent<NativeProps>;
+
+interface NativeCommands {
+  +changeBackgroundColor: (
+    viewRef: React.ElementRef<AnswerViewerViewType>,
+    color: string,
+  ) => void;
+}
+
+export const Commands: NativeCommands = codegenNativeCommands<NativeCommands>({
+  supportedCommands: ['changeBackgroundColor'],
+});
+
+export default (codegenNativeComponent<NativeProps>(
+  'AnswerViewer',
+): AnswerViewerViewType);