Merge pull request #89 from ComponentDriven/next

Release 0.1.6

Author: kasperpeulen

src/story.test.ts

@@ -34,6 +34,15 @@ type ButtonArgs = {
 
 const Button = (props: ButtonArgs) => 'Button';
 
+let a = 1;
+async function doSomething() {
+  a = 2;
+}
+
+async function cleanup() {
+  a = 1;
+}
+
 // NOTE Various kind usages
 const simple: XMeta = {
   title: 'simple',
@@ -42,6 +51,10 @@ const simple: XMeta = {
   decorators: [(storyFn, context) => `withDecorator(${storyFn(context)})`],
   parameters: { a: () => null, b: NaN, c: Symbol('symbol') },
   loaders: [() => Promise.resolve({ d: '3' })],
+  async beforeEach() {
+    await doSomething();
+    return cleanup;
+  },
   args: { x: '1' },
   argTypes: { x: { type: { name: 'string' } } },
 };
@@ -54,6 +67,10 @@ const strict: XMeta<ButtonArgs> = {
   parameters: { a: () => null, b: NaN, c: Symbol('symbol') },
   loaders: [() => Promise.resolve({ d: '3' })],
   args: { x: '1' },
+  async beforeEach() {
+    await doSomething();
+    return cleanup;
+  },
   argTypes: { x: { type: { name: 'string' } } },
 };
 
@@ -86,6 +103,10 @@ CSF1Story.story = {
   decorators: [(storyFn) => `Wrapped(${storyFn()}`],
   parameters: { a: [1, '2', {}], b: undefined, c: Button },
   loaders: [() => Promise.resolve({ d: '3' })],
+  async beforeEach() {
+    await doSomething();
+    return cleanup;
+  },
   args: { a: 1 },
 };
 

src/story.ts

@@ -259,6 +259,13 @@ export type LoaderFunction<TRenderer extends Renderer = Renderer, TArgs = Args>
   context: StoryContextForLoaders<TRenderer, TArgs>
 ) => Promise<Record<string, any> | void> | Record<string, any> | void;
 
+type Awaitable<T> = T | PromiseLike<T>;
+export type CleanupCallback = () => Awaitable<unknown>;
+
+export type BeforeEach<TRenderer extends Renderer = Renderer, TArgs = Args> = (
+  context: StoryContext<TRenderer, TArgs>
+) => Awaitable<CleanupCallback | void>;
+
 export interface StoryContext<TRenderer extends Renderer = Renderer, TArgs = Args>
   extends StoryContextForLoaders<TRenderer, TArgs> {
   loaded: Record<string, any>;
@@ -356,6 +363,16 @@ export type BaseAnnotations<TRenderer extends Renderer = Renderer, TArgs = Args>
    */
   loaders?: LoaderFunction<TRenderer, TArgs>[] | LoaderFunction<TRenderer, TArgs>;
 
+  /**
+   * Function to be called before each story. When the function is async, it will be awaited.
+   *
+   * `beforeEach` can be added to preview, the default export and to a specific story.
+   * They are run (and awaited) in the order: preview, default export, story
+   *
+   * A cleanup function can be returned.
+   */
+  beforeEach?: BeforeEach<TRenderer, TArgs>[] | BeforeEach<TRenderer, TArgs>;
+
   /**
    * Define a custom render function for the story(ies). If not passed, a default render function by the renderer will be used.
    */