perf: optimization BackTop and Anchor components scrollTo func

components/_util/__tests__/scrollTo.test.js

@@ -0,0 +1,43 @@
+import scrollTo from '../scrollTo';
+import { sleep } from '../../../tests/utils';
+
+describe('Test ScrollTo function', () => {
+  it('test scrollTo', async () => {
+    const scrollToSpy = jest.spyOn(window, 'scrollTo').mockImplementation((x, y) => {
+      const w = window;
+      w.scrollY = y;
+      w.pageYOffset = y;
+    });
+    scrollTo(0, 1000);
+    await sleep(1000);
+    expect(window.pageYOffset).toBe(1000);
+    scrollToSpy.mockRestore();
+  });
+
+  it('test unknow easing funciton', () => {
+    const warnSpy = jest.spyOn(console, 'warn').mockImplementation(() => {});
+    scrollTo(0, 0, {
+      ease: 'ffff',
+    });
+    expect(warnSpy).toHaveBeenCalledWith('Unkonw easing funciton in scrollTo');
+    warnSpy.mockRestore();
+  });
+
+  it('test callback - option', async () => {
+    const cbMock = jest.fn();
+    scrollTo(0, 1000, {
+      callback: cbMock,
+    });
+    await sleep(1000);
+    expect(cbMock).toHaveBeenCalledTimes(1);
+  });
+
+  it('test getContainer - option', async () => {
+    const div = document.createElement('div');
+    scrollTo(0, 1000, {
+      getContainer: () => div,
+    });
+    await sleep(1000);
+    expect(div.scrollTop).toBe(1000);
+  });
+});

components/_util/eases.ts

@@ -0,0 +1,17 @@
+const Eases = {
+  easeInOutCubic: (t: number, b: number, c: number, d: number) => {
+    const cc = c - b;
+    t /= d / 2;
+    if (t < 1) {
+      return (cc / 2) * t * t * t + b;
+    }
+    return (cc / 2) * ((t -= 2) * t * t + 2) + b;
+  },
+  easeOutCubic: (t: number, b: number, c: number, d: number) => {
+    const cc = c - b;
+    t /= d - 1;
+    return cc * (t * t * t + 1) + b;
+  },
+};
+
+export default Eases;

components/_util/scrollTo.ts

@@ -0,0 +1,53 @@
+import raf from 'raf';
+import getScroll from './getScroll';
+import Eases from './eases';
+
+type easeType = keyof typeof Eases;
+
+interface ScrollToOptions {
+  /** Scroll container, deault as window */
+  getContainer?: () => HTMLElement | Window;
+  /** Scroll end callback */
+  callback?: () => any;
+  /** Animation duration, default as 450 */
+  duration?: number;
+  /** easing function name, default as easeInOutCubic */
+  ease?: easeType;
+}
+
+// TODO: support x
+export default function scrollTo(x: number, y: number, options: ScrollToOptions = {}) {
+  const {
+    getContainer = () => window,
+    callback,
+    duration = 450,
+    ease = 'easeInOutCubic',
+  } = options;
+
+  const container = getContainer();
+  const scrollTop = getScroll(container, true);
+  const startTime = Date.now();
+  let easeFunc = Eases[ease];
+
+  if (!easeFunc) {
+    console.warn('Unkonw easing funciton in scrollTo');
+    easeFunc = Eases.easeInOutCubic;
+  }
+
+  const frameFunc = () => {
+    const timestamp = Date.now();
+    const time = timestamp - startTime;
+    const nextScrollTop = easeFunc(time > duration ? duration : time, scrollTop, y, duration);
+    if (container === window) {
+      window.scrollTo(x, nextScrollTop);
+    } else {
+      (container as HTMLElement).scrollTop = nextScrollTop;
+    }
+    if (time < duration) {
+      raf(frameFunc);
+    } else {
+      if (typeof callback === 'function') callback();
+    }
+  };
+  raf(frameFunc);
+}

components/anchor/Anchor.tsx

@@ -7,6 +7,7 @@ import raf from 'raf';
 import Affix from '../affix';
 import AnchorLink from './AnchorLink';
 import { ConfigConsumer, ConfigConsumerProps } from '../config-provider';
+import scrollTo from '../_util/scrollTo';
 import getScroll from '../_util/getScroll';
 
 function getDefaultContainer() {
@@ -35,54 +36,7 @@ function getOffsetTop(element: HTMLElement, container: AnchorContainer): number
   return rect.top;
 }
 
-function easeInOutCubic(t: number, b: number, c: number, d: number) {
-  const cc = c - b;
-  t /= d / 2;
-  if (t < 1) {
-    return (cc / 2) * t * t * t + b;
-  }
-  const r = (cc / 2) * ((t -= 2) * t * t + 2) + b;
-  // fix return value more than target value
-  return cc > 0 ? (r > c ? c : r) : r < c ? c : r;
-}
-
 const sharpMatcherRegx = /#([^#]+)$/;
-function scrollTo(
-  href: string,
-  targetOffset = 0,
-  getContainer: () => AnchorContainer,
-  callback = () => {},
-) {
-  const container = getContainer();
-  const scrollTop = getScroll(container, true);
-  const sharpLinkMatch = sharpMatcherRegx.exec(href);
-  if (!sharpLinkMatch) {
-    return;
-  }
-  const targetElement = document.getElementById(sharpLinkMatch[1]);
-  if (!targetElement) {
-    return;
-  }
-  const eleOffsetTop = getOffsetTop(targetElement, container);
-  const targetScrollTop = scrollTop + eleOffsetTop - targetOffset;
-  const startTime = Date.now();
-  const frameFunc = () => {
-    const timestamp = Date.now();
-    const time = timestamp - startTime;
-    const nextScrollTop = easeInOutCubic(time, scrollTop, targetScrollTop, 450);
-    if (container === window) {
-      window.scrollTo(window.pageXOffset, nextScrollTop);
-    } else {
-      (container as HTMLElement).scrollTop = nextScrollTop;
-    }
-    if (time < 450) {
-      raf(frameFunc);
-    } else {
-      callback();
-    }
-  };
-  raf(frameFunc);
-}
 
 type Section = {
   link: string;
@@ -208,7 +162,35 @@ export default class Anchor extends React.Component<AnchorProps, AnchorState> {
     if (this.scrollEvent) {
       this.scrollEvent.remove();
     }
-  }
+  };
+
+  handleScrollTo = (link: string) => {
+    const { offsetTop, getContainer, targetOffset } = this.props as AnchorDefaultProps;
+
+    this.setState({ activeLink: link });
+    const container = getContainer();
+    const scrollTop = getScroll(container, true);
+    const sharpLinkMatch = sharpMatcherRegx.exec(link);
+    if (!sharpLinkMatch) {
+      return;
+    }
+    const targetElement = document.getElementById(sharpLinkMatch[1]);
+    if (!targetElement) {
+      return;
+    }
+
+    const eleOffsetTop = getOffsetTop(targetElement, container);
+    let y = scrollTop + eleOffsetTop;
+    y -= targetOffset !== undefined ? targetOffset : offsetTop || 0;
+    this.animating = true;
+
+    scrollTo(window.pageXOffset, y, {
+      callback: () => {
+        this.animating = false;
+      },
+      getContainer,
+    });
+  };
 
   getCurrentAnchor(offsetTop = 0, bounds = 5): string {
     const { getCurrentAnchor } = this.props;
@@ -267,15 +249,6 @@ export default class Anchor extends React.Component<AnchorProps, AnchorState> {
     }
   };
 
-  handleScrollTo = (link: string) => {
-    const { offsetTop, getContainer, targetOffset } = this.props as AnchorDefaultProps;
-    this.animating = true;
-    this.setState({ activeLink: link });
-    scrollTo(link, targetOffset !== undefined ? targetOffset : offsetTop, getContainer, () => {
-      this.animating = false;
-    });
-  };
-
   updateInk = () => {
     if (typeof document === 'undefined') {
       return;

components/back-top/__tests__/index.test.js

@@ -1,16 +1,23 @@
 import React from 'react';
 import { mount } from 'enzyme';
+import { sleep } from '../../../tests/utils';
 import BackTop from '..';
 
 describe('BackTop', () => {
   it('should scroll to top after click it', async () => {
     const wrapper = mount(<BackTop visibilityHeight={-1} />);
-    document.documentElement.scrollTop = 400;
+    const scrollToSpy = jest.spyOn(window, 'scrollTo').mockImplementation((x, y) => {
+      const w = window;
+      w.scrollY = y;
+      w.pageYOffset = y;
+    });
+    window.scrollTo(0, 400);
     // trigger scroll manually
     wrapper.instance().handleScroll();
-    await new Promise(resolve => setTimeout(resolve, 0));
+    await sleep();
     wrapper.find('.ant-back-top').simulate('click');
-    await new Promise(resolve => setTimeout(resolve, 1000));
-    expect(Math.abs(Math.round(document.documentElement.scrollTop))).toBe(0);
+    await sleep(1000);
+    expect(window.pageYOffset).toBe(0);
+    scrollToSpy.mockRestore();
   });
 });

components/back-top/index.tsx

@@ -3,20 +3,9 @@ import Animate from 'rc-animate';
 import addEventListener from 'rc-util/lib/Dom/addEventListener';
 import classNames from 'classnames';
 import omit from 'omit.js';
-import raf from 'raf';
 import { ConfigConsumer, ConfigConsumerProps } from '../config-provider';
 import getScroll from '../_util/getScroll';
-
-const easeInOutCubic = (t: number, b: number, c: number, d: number) => {
-  const cc = c - b;
-  t /= d / 2;
-  if (t < 1) {
-    return (cc / 2) * t * t * t + b;
-  }
-  return (cc / 2) * ((t -= 2) * t * t + 2) + b;
-};
-
-function noop() {}
+import scrollTo from '../_util/scrollTo';
 
 function getDefaultTarget() {
   return window;
@@ -79,20 +68,13 @@ export default class BackTop extends React.Component<BackTopProps, any> {
   };
 
   scrollToTop = (e: React.MouseEvent<HTMLDivElement>) => {
-    const scrollTop = this.getCurrentScrollTop();
-    const startTime = Date.now();
-    const frameFunc = () => {
-      const timestamp = Date.now();
-      const time = timestamp - startTime;
-      this.setScrollTop(easeInOutCubic(time, scrollTop, 0, 450));
-      if (time < 450) {
-        raf(frameFunc);
-      } else {
-        this.setScrollTop(0);
-      }
-    };
-    raf(frameFunc);
-    (this.props.onClick || noop)(e);
+    const { target = getDefaultTarget } = this.props;
+    scrollTo(window.pageXOffset, 0, {
+      getContainer: target,
+    });
+    if (typeof this.props.onClick === 'function') {
+      this.props.onClick(e);
+    }
   };
 
   handleScroll = () => {

tests/utils.js

@@ -8,3 +8,5 @@ export function setMockDate(dateString = '2017-09-18T03:30:07.795') {
 export function resetMockDate() {
   MockDate.reset();
 }
+
+export const sleep = (timeout = 0) => new Promise(resolve => setTimeout(resolve, timeout));