feat(Anchor): add targetOffset prop

components/_util/__tests__/easings.test.js

@@ -0,0 +1,13 @@
+import { easeInOutCubic } from '../easings';
+
+describe('Test easings', () => {
+  it('easeInOutCubic return value', () => {
+    const nums = [];
+    // eslint-disable-next-line no-plusplus
+    for (let index = 0; index < 5; index++) {
+      nums.push(easeInOutCubic(index, 1, 5, 4));
+    }
+
+    expect(nums).toEqual([1, 1.25, 3, 4.75, 5]);
+  });
+});

components/_util/__tests__/scrollTo.test.js

@@ -0,0 +1,56 @@
+import scrollTo from '../scrollTo';
+
+describe('Test ScrollTo function', () => {
+  let dateNowMock;
+
+  beforeAll(() => {
+    jest.useFakeTimers();
+  });
+
+  afterAll(() => {
+    jest.useRealTimers();
+  });
+
+  beforeEach(() => {
+    dateNowMock = jest
+      .spyOn(Date, 'now')
+      .mockImplementationOnce(() => 0)
+      .mockImplementationOnce(() => 1000);
+  });
+
+  afterEach(() => {
+    dateNowMock.mockRestore();
+  });
+
+  it('test scrollTo', async () => {
+    const scrollToSpy = jest.spyOn(window, 'scrollTo').mockImplementation((x, y) => {
+      window.scrollY = y;
+      window.pageYOffset = y;
+    });
+
+    scrollTo(1000);
+
+    jest.runAllTimers();
+    expect(window.pageYOffset).toBe(1000);
+
+    scrollToSpy.mockRestore();
+  });
+
+  it('test callback - option', async () => {
+    const cbMock = jest.fn();
+    scrollTo(1000, {
+      callback: cbMock,
+    });
+    jest.runAllTimers();
+    expect(cbMock).toHaveBeenCalledTimes(1);
+  });
+
+  it('test getContainer - option', async () => {
+    const div = document.createElement('div');
+    scrollTo(1000, {
+      getContainer: () => div,
+    });
+    jest.runAllTimers();
+    expect(div.scrollTop).toBe(1000);
+  });
+});

components/_util/easings.ts

@@ -0,0 +1,9 @@
+// eslint-disable-next-line import/prefer-default-export
+export 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;
+  }
+  return (cc / 2) * ((t -= 2) * t * t + 2) + b;
+}

components/_util/scrollTo.ts

@@ -0,0 +1,37 @@
+import raf from 'raf';
+import getScroll from './getScroll';
+import { easeInOutCubic } from './easings';
+
+interface ScrollToOptions {
+  /** Scroll container, default as window */
+  getContainer?: () => HTMLElement | Window;
+  /** Scroll end callback */
+  callback?: () => any;
+  /** Animation duration, default as 450 */
+  duration?: number;
+}
+
+export default function scrollTo(y: number, options: ScrollToOptions = {}) {
+  const { getContainer = () => window, callback, duration = 450 } = options;
+
+  const container = getContainer();
+  const scrollTop = getScroll(container, true);
+  const startTime = Date.now();
+
+  const frameFunc = () => {
+    const timestamp = Date.now();
+    const time = timestamp - startTime;
+    const nextScrollTop = easeInOutCubic(time > duration ? duration : time, scrollTop, y, duration);
+    if (container === window) {
+      window.scrollTo(window.pageXOffset, nextScrollTop);
+    } else {
+      (container as HTMLElement).scrollTop = nextScrollTop;
+    }
+    if (time < duration) {
+      raf(frameFunc);
+    } else if (typeof callback === 'function') {
+      callback();
+    }
+  };
+  raf(frameFunc);
+}

components/anchor/Anchor.tsx

@@ -3,10 +3,10 @@ import * as ReactDOM from 'react-dom';
 import * as PropTypes from 'prop-types';
 import classNames from 'classnames';
 import addEventListener from 'rc-util/lib/Dom/addEventListener';
-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() {
@@ -35,52 +35,7 @@ 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;
-  }
-  return (cc / 2) * ((t -= 2) * t * t + 2) + b;
-}
-
 const sharpMatcherRegx = /#([^#]+)$/;
-function scrollTo(
-  href: string,
-  offsetTop = 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 - offsetTop;
-  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;
@@ -105,6 +60,8 @@ export interface AnchorProps {
     e: React.MouseEvent<HTMLElement>,
     link: { title: React.ReactNode; href: string },
   ) => void;
+  /** Scroll to target offset value, if none, it's offsetTop prop value or 0. */
+  targetOffset?: number;
 }
 
 export interface AnchorState {
@@ -245,6 +202,34 @@ export default class Anchor extends React.Component<AnchorProps, AnchorState> {
     return '';
   }
 
+  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(y, {
+      callback: () => {
+        this.animating = false;
+      },
+      getContainer,
+    });
+  };
+
   saveInkNode = (node: HTMLSpanElement) => {
     this.inkNode = node;
   };
@@ -254,24 +239,18 @@ export default class Anchor extends React.Component<AnchorProps, AnchorState> {
       return;
     }
     const { activeLink } = this.state;
-    const { offsetTop, bounds } = this.props;
-    const currentActiveLink = this.getCurrentAnchor(offsetTop, bounds);
+    const { offsetTop, bounds, targetOffset } = this.props;
+    const currentActiveLink = this.getCurrentAnchor(
+      targetOffset !== undefined ? targetOffset : offsetTop || 0,
+      bounds,
+    );
     if (activeLink !== currentActiveLink) {
       this.setState({
         activeLink: currentActiveLink,
       });
     }
   };
 
-  handleScrollTo = (link: string) => {
-    const { offsetTop, getContainer } = this.props as AnchorDefaultProps;
-    this.animating = true;
-    this.setState({ activeLink: link });
-    scrollTo(link, offsetTop, getContainer, () => {
-      this.animating = false;
-    });
-  };
-
   updateInk = () => {
     if (typeof document === 'undefined') {
       return;

components/anchor/__tests__/Anchor.test.js

@@ -1,12 +1,29 @@
 import React from 'react';
 import { mount } from 'enzyme';
 import Anchor from '..';
+import { spyElementPrototypes } from '../../__tests__/util/domHook';
+import { sleep } from '../../../tests/utils';
 
 const { Link } = Anchor;
 
-const delay = timeout => new Promise(resolve => setTimeout(resolve, timeout));
-
 describe('Anchor Render', () => {
+  const getBoundingClientRectMock = jest.fn(() => ({
+    width: 100,
+    height: 100,
+    top: 1000,
+  }));
+  const getClientRectsMock = jest.fn(() => ({
+    length: 1,
+  }));
+  const headingSpy = spyElementPrototypes(HTMLHeadingElement, {
+    getBoundingClientRect: getBoundingClientRectMock,
+    getClientRects: getClientRectsMock,
+  });
+
+  afterAll(() => {
+    headingSpy.mockRestore();
+  });
+
   it('Anchor render perfectly', () => {
     const wrapper = mount(
       <Anchor>
@@ -64,7 +81,7 @@ describe('Anchor Render', () => {
     wrapper.instance().handleScrollTo('##API');
     expect(wrapper.instance().state.activeLink).toBe('##API');
     expect(scrollToSpy).not.toHaveBeenCalled();
-    await delay(1000);
+    await sleep(1000);
     expect(scrollToSpy).toHaveBeenCalled();
   });
 
@@ -154,7 +171,7 @@ describe('Anchor Render', () => {
       </Anchor>,
     );
     const removeListenerSpy = jest.spyOn(wrapper.instance().scrollEvent, 'remove');
-    await delay(1000);
+    await sleep(1000);
     wrapper.setProps({ getContainer: getContainerB });
     expect(removeListenerSpy).not.toHaveBeenCalled();
   });
@@ -187,7 +204,7 @@ describe('Anchor Render', () => {
     );
     const removeListenerSpy = jest.spyOn(wrapper.instance().scrollEvent, 'remove');
     expect(removeListenerSpy).not.toHaveBeenCalled();
-    await delay(1000);
+    await sleep(1000);
     wrapper.setProps({ getContainer: getContainerB });
     expect(removeListenerSpy).toHaveBeenCalled();
   });
@@ -239,7 +256,7 @@ describe('Anchor Render', () => {
     );
     const removeListenerSpy = jest.spyOn(wrapper.instance().scrollEvent, 'remove');
     expect(removeListenerSpy).not.toHaveBeenCalled();
-    await delay(1000);
+    await sleep(1000);
     holdContainer.container = document.getElementById('API2');
     wrapper.setProps({ 'data-only-trigger-re-render': true });
     expect(removeListenerSpy).toHaveBeenCalled();
@@ -255,4 +272,51 @@ describe('Anchor Render', () => {
     );
     expect(wrapper.instance().state.activeLink).toBe('#API2');
   });
+
+  it('Anchor targetOffset prop', async () => {
+    jest.useFakeTimers();
+
+    let dateNowMock;
+
+    function dataNowMockFn() {
+      return jest
+        .spyOn(Date, 'now')
+        .mockImplementationOnce(() => 0)
+        .mockImplementationOnce(() => 1000);
+    }
+
+    dateNowMock = dataNowMockFn();
+
+    const scrollToSpy = jest.spyOn(window, 'scrollTo');
+    let root = document.getElementById('root');
+    if (!root) {
+      root = document.createElement('div', { id: 'root' });
+      root.id = 'root';
+      document.body.appendChild(root);
+    }
+    mount(<h1 id="API">Hello</h1>, { attachTo: root });
+    const wrapper = mount(
+      <Anchor>
+        <Link href="#API" title="API" />
+      </Anchor>,
+    );
+    wrapper.instance().handleScrollTo('#API');
+    jest.runAllTimers();
+    expect(scrollToSpy).toHaveBeenLastCalledWith(0, 1000);
+    dateNowMock = dataNowMockFn();
+
+    wrapper.setProps({ offsetTop: 100 });
+    wrapper.instance().handleScrollTo('#API');
+    jest.runAllTimers();
+    expect(scrollToSpy).toHaveBeenLastCalledWith(0, 900);
+    dateNowMock = dataNowMockFn();
+
+    wrapper.setProps({ targetOffset: 200 });
+    wrapper.instance().handleScrollTo('#API');
+    jest.runAllTimers();
+    expect(scrollToSpy).toHaveBeenLastCalledWith(0, 800);
+
+    dateNowMock.mockRestore();
+    jest.useRealTimers();
+  });
 });