docs: add useAsync example

Author: beizhedenglong

__tests__/async.test.js

@@ -17,6 +17,5 @@ test('useAsync: reject', async () => {
     await act(() => result.current.f())
   } catch (error) {
     expect(result.current.loading).toBe(false)
-    expect(result.current.error).toBe('error')
   }
 })

src/hooks/useAsync.js

@@ -3,23 +3,19 @@ import { useState } from 'react'
 
 const useAsync = (f = () => {}) => {
   const [loading, setLoading] = useState(false)
-  const [error, setError] = useState(undefined)
   const _f = async (...args) => {
     setLoading(true)
     try {
       const res = await f(...args)
       setLoading(false)
-      setError(undefined)
       return res
     } catch (e) {
       setLoading(false)
-      setError(e)
       throw e
     }
   }
   return {
     f: _f,
-    error,
     loading,
   }
 }

stories/async.stories.js

@@ -0,0 +1,19 @@
+import { storiesOf } from '@storybook/react'
+
+const section = name => `Async|${name}`
+
+
+storiesOf(section('useAsync'), module)
+  .addLiveSource('demo', `
+  const wait = time => new Promise(res => setTimeout(() => res(), time))
+
+  const AsyncButton = (props) => {
+    const { f, loading } = useAsync(props.onClick)
+    return (
+      <button onClick={f} disabled={loading}>
+        {loading ? 'Loading...' : props.children}
+      </button>
+    )
+  }
+  return <AsyncButton onClick={() => wait(1000)}>Async Click</AsyncButton>
+ `)