feat: add useHash hook

Author: whinc

Diff for: docs/useHash.md

@@ -0,0 +1,39 @@
+# `useHash`
+
+React sensor hook that tracks browser's location hash.
+
+## Usage
+
+```jsx
+import {useHash} from 'react-use';
+
+const Demo = () => {
+  const [hash, setHash] = useHash();
+
+  useMount(() => {
+    setHash('#/path/to/page?userId=123');
+  });
+
+  return (
+    <div>
+      <div>window.location.href:</div>
+      <div>
+        <pre>{window.location.href}</pre>
+      </div>
+      <div>Edit hash: </div>
+      <div>
+        <input style={{ width: '100%' }} value={hash} onChange={e => setHash(e.target.value)} />
+      </div>
+    </div>
+  );
+};
+```
+
+## API
+
+`const [hash, setHash] = useHash()`
+
+Get latest url hash with `hash` and set url hash with `setHash`.
+
+- `hash: string`: get current url hash. listen to `hashchange` event.
+- `setHash: (newHash: string) => void`: change url hash. Invoke this method will trigger `hashchange` event.

Diff for: src/index.ts

@@ -110,3 +110,4 @@ export { useRendersCount } from './useRendersCount';
 export { useFirstMountState } from './useFirstMountState';
 export { default as useSet } from './useSet';
 export { createGlobalState } from './createGlobalState';
+export { useHash } from './useHash'

Diff for: src/useHash.ts

@@ -0,0 +1,27 @@
+import { useState, useCallback } from "react"
+import useLifecycles from "./useLifecycles"
+
+/**
+ * read and write url hash, response to url hash change
+ */
+export const useHash = () => {
+  const [hash, setHash] = useState(() => window.location.hash)
+
+  const onHashChange = useCallback(() => {
+    setHash(window.location.hash)
+  }, [])
+
+  useLifecycles(() => {
+    window.addEventListener('hashchange', onHashChange)
+  }, () => {
+    window.removeEventListener('hashchange', onHashChange)
+  })
+
+  const _setHash = useCallback((newHash: string) => {
+    if (newHash !== hash) {
+      window.location.hash = newHash
+    }
+  }, [hash])
+
+  return [hash, _setHash] as const
+}

Diff for: stories/useHash.story.tsx

@@ -0,0 +1,29 @@
+import { storiesOf } from '@storybook/react';
+import * as React from 'react';
+import { useHash, useMount } from '../src';
+import ShowDocs from './util/ShowDocs';
+
+const Demo = () => {
+  const [hash, setHash] = useHash();
+
+  useMount(() => {
+    setHash('#/path/to/page?userId=123');
+  });
+
+  return (
+    <div>
+      <div>window.location.href:</div>
+      <div>
+        <pre>{window.location.href}</pre>
+      </div>
+      <div>Edit hash: </div>
+      <div>
+        <input style={{ width: '100%' }} value={hash} onChange={e => setHash(e.target.value)} />
+      </div>
+    </div>
+  );
+};
+
+storiesOf('Sensors|useHash', module)
+  .add('Docs', () => <ShowDocs md={require('../docs/useHash.md')} />)
+  .add('Demo', () => <Demo />);

Diff for: tests/useHash.test.ts

@@ -0,0 +1,54 @@
+import { renderHook, act } from '@testing-library/react-hooks';
+import { useHash } from '../src/useHash';
+
+(global as any).window = Object.create(window);
+let mockHash = '#';
+const mockLocation = {};
+Object.defineProperty(mockLocation, 'hash', {
+  get() {
+    return mockHash;
+  },
+  set(newHash) {
+    mockHash = newHash;
+    window.dispatchEvent(new HashChangeEvent('hashchange'));
+  },
+});
+Object.defineProperty(window, 'location', {
+  value: mockLocation,
+});
+
+beforeEach(() => {
+  window.location.hash = '#';
+});
+
+test('returns current url hash', () => {
+  window.location.hash = '#abc';
+
+  const { result } = renderHook(() => useHash());
+
+  const hash = result.current[0];
+  expect(hash).toBe('#abc');
+});
+
+test('returns latest url hash when change the hash with setHash', () => {
+  const { result } = renderHook(() => useHash());
+  const hash = result.current[0];
+  const setHash = result.current[1];
+  expect(hash).toBe('#');
+  act(() => {
+    setHash('#abc');
+  });
+  const hash2 = result.current[0];
+  expect(hash2).toBe('#abc');
+});
+
+it('returns latest url hash when change the hash with "hashchange" event', () => {
+  const {result} = renderHook(() => useHash());
+  const hash = result.current[0]
+  expect(hash).toBe('#');
+  act(() => {
+    window.location.hash = '#abc'
+  })
+  const hash2 = result.current[0]
+  expect(hash2).toBe('#abc');
+});