refactor: move svelte loader of addon-storyshots framework part to TS

addons/storyshots/storyshots-core/src/frameworks/Loader.ts

@@ -1,6 +1,6 @@
 import { StoryshotsOptions } from '../api/StoryshotsOptions';
 
-type SupportedFramework = 'angular' | 'html' | 'preact' | 'react' | 'riot' | 'react-native';
+type SupportedFramework = 'angular' | 'html' | 'preact' | 'react' | 'riot' | 'react-native' | 'svelte';
 
 export type RenderTree = (story: any) => any;
 

addons/storyshots/storyshots-core/src/frameworks/svelte/loader.ts

@@ -1,14 +1,16 @@
 import global from 'global';
 import hasDependency from '../hasDependency';
 import configure from '../configure';
+import { Loader } from '../Loader';
+import { StoryshotsOptions } from '../../api/StoryshotsOptions';
 
-function test(options) {
+function test(options: StoryshotsOptions): boolean {
   return (
     options.framework === 'svelte' || (!options.framework && hasDependency('@storybook/svelte'))
   );
 }
 
-function load(options) {
+function load(options: StoryshotsOptions) {
   global.STORYBOOK_ENV = 'svelte';
 
   const { configPath, config } = options;
@@ -17,7 +19,7 @@ function load(options) {
   configure({ configPath, config, storybook });
 
   return {
-    framework: 'svelte',
+    framework: 'svelte' as const,
     renderTree: require.requireActual('./renderTree').default,
     renderShallowTree: () => {
       throw new Error('Shallow renderer is not supported for svelte');
@@ -26,7 +28,9 @@ function load(options) {
   };
 }
 
-export default {
+const svelteLoader: Loader = {
   load,
   test,
 };
+
+export default svelteLoader;

addons/storyshots/storyshots-core/src/frameworks/svelte/renderTree.ts

@@ -11,7 +11,7 @@ import { document } from 'global';
  * If we don't render to HTML, we will get a snapshot of the raw story
  * i.e. ({ Component, data }).
  */
-function getRenderedTree(story) {
+function getRenderedTree(story: any) {
   const { Component, props } = story.render();
 
   const DefaultCompatComponent = Component.default || Component;