add web-component story types

app/web-components/src/client/preview/types.ts

@@ -1,5 +1,6 @@
 // eslint-disable-next-line import/no-extraneous-dependencies
 import { TemplateResult, SVGTemplateResult } from 'lit-element';
+import { Args as DefaultArgs, Annotations, BaseMeta, BaseStory } from '@storybook/addons';
 
 export { RenderContext } from '@storybook/core';
 
@@ -19,3 +20,18 @@ export interface ShowErrorArgs {
   title: string;
   description: string;
 }
+
+/**
+ * Metadata to configure the stories for a component.
+ *
+ * @see [Default export](https://storybook.js.org/docs/formats/component-story-format/#default-export)
+ */
+export type Meta<Args = DefaultArgs> = BaseMeta<string> & Annotations<Args, StoryFnHtmlReturnType>;
+
+/**
+ * Story function that represents a component example.
+ *
+ * @see [Named Story exports](https://storybook.js.org/docs/formats/component-story-format/#named-story-exports)
+ */
+export type Story<Args = DefaultArgs> = BaseStory<Args, StoryFnHtmlReturnType> &
+  Annotations<Args, StoryFnHtmlReturnType>;

package.json

@@ -299,4 +299,4 @@
       ]
     ]
   }
-}
+}