diff --git a/package.json b/package.json
index 92a5c257421b..7bc15f8efec3 100644
--- a/package.json
+++ b/package.json
@@ -81,6 +81,7 @@
     "babel-plugin-syntax-jsx": "^6.18.0",
     "babel-plugin-transform-class-properties": "^6.24.1",
     "babel-plugin-transform-taroapi": "file:packages/babel-plugin-transform-taroapi",
+    "babel-preset-power-assert": "^3.0.0",
     "conventional-changelog-cli": "^2.0.1",
     "copy": "^0.3.2",
     "css-loader": "^0.28.10",
@@ -122,6 +123,7 @@
     "node-sass": "^4.7.2",
     "npm-run-all": "^4.1.2",
     "ora": "^2.1.0",
+    "power-assert": "^1.6.1",
     "prettier": "^1.18.2",
     "react": "^16.10.2",
     "react-dom": "^16.10.2",
diff --git a/packages/taro-components/__tests__/audio.spec.js b/packages/taro-components/__tests__/audio.spec.js
index b5a5b56bfe36..c4d72a2cd411 100644
--- a/packages/taro-components/__tests__/audio.spec.js
+++ b/packages/taro-components/__tests__/audio.spec.js
@@ -2,6 +2,7 @@ import './polyfill'
 import * as React from 'nervjs'
 import { Audio } from '../h5'
 import { waitForChange } from './utils'
+import * as assert from 'assert'
 // eslint-disable-next-line @typescript-eslint/no-unused-vars
 const h = React.createElement
 
@@ -51,6 +52,11 @@ describe('Audio', () => {
       }
 
       render () {
+        const {
+          src,
+          controls,
+          loop
+        } = this.state
         return <Audio ref={ref} src={src} controls={controls} loop={loop} />
       }
     }
@@ -68,18 +74,17 @@ describe('Audio', () => {
      * @type {HTMLAudioElement}
      */
     const audio = node.childNodes[0]
-    expect(audio instanceof HTMLAudioElement).toBeTruthy()
-    expect(audio.src).toBe(location.origin + '/' + src)
-    expect(audio.controls).toBe(controls)
-    expect(audio.loop).toBe(loop)
+    assert(audio instanceof HTMLAudioElement)
+    assert(audio.src === location.origin + '/' + src)
+    assert(audio.controls === controls)
+    assert(audio.loop === loop)
 
     instance.setState({
       controls: false,
       loop: false
     })
-    instance.forceUpdate()
-
-    expect(audio.controls).toBe(true)
-    expect(audio.loop).toBe(true)
+    await waitForChange(audio)
+    assert(audio.controls === false)
+    assert(audio.loop === false)
   })
 })
diff --git a/packages/taro-components/__tests__/block.spec.js b/packages/taro-components/__tests__/block.spec.js
new file mode 100644
index 000000000000..e0b3a8247630
--- /dev/null
+++ b/packages/taro-components/__tests__/block.spec.js
@@ -0,0 +1,52 @@
+import * as React from 'nervjs'
+import { Block } from '../h5'
+import { waitForChange } from './utils'
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+const h = React.createElement
+
+describe('Block', () => {
+  /**
+   * @type {HTMLElement}
+   */
+  let scratch
+
+  beforeAll(async () => {
+    scratch = document.createElement('div')
+    document.body.appendChild(scratch)
+  })
+
+  beforeEach(async () => {
+    scratch = document.createElement('div')
+    document.body.appendChild(scratch)
+  })
+
+  afterAll(async () => {
+    scratch.parentNode.removeChild(scratch)
+    scratch = null
+  })
+
+  it('有一个空的占位元素，并且 slot 能够使用', async () => {
+    const ref = React.createRef()
+
+    class App extends React.Component {
+      render () {
+        return <Block ref={ref}>
+          <div />
+          <div />
+        </Block>
+      }
+    }
+
+    React.render(<App />, scratch)
+
+    /**
+     * @type {HTMLElement}
+     */
+    const node = ref.current
+
+    await waitForChange(node)
+
+    expect(scratch.childNodes.length).toBe(1)
+    expect(node.childNodes.length).toBe(2)
+  })
+})
diff --git a/packages/taro-components/__tests__/button.spec.js b/packages/taro-components/__tests__/button.spec.js
new file mode 100644
index 000000000000..c61f98563509
--- /dev/null
+++ b/packages/taro-components/__tests__/button.spec.js
@@ -0,0 +1,203 @@
+import * as React from 'nervjs'
+import { Button } from '../h5'
+import { waitForChange, delay } from './utils'
+import * as assert from 'assert'
+import * as sinon from 'sinon'
+
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+const h = React.createElement
+
+function fireTouchEvent (el, type) {
+  const e = document.createEvent('UIEvent')
+  e.initEvent(type, true, true)
+  el.dispatchEvent(e)
+}
+
+describe('Button', () => {
+  /**
+   * @type {HTMLElement}
+   */
+  let scratch
+
+  beforeAll(async () => {
+    scratch = document.createElement('div')
+    document.body.appendChild(scratch)
+  })
+
+  beforeEach(async () => {
+    scratch.parentNode.removeChild(scratch)
+    scratch = document.createElement('div')
+    document.body.appendChild(scratch)
+  })
+
+  afterAll(async () => {
+    scratch.parentNode.removeChild(scratch)
+    scratch = null
+  })
+
+  it('props', async () => {
+    const ref = React.createRef()
+
+    const size = 'mini'
+    const plain = true
+    const loading = true
+    const disabled = false
+    /**
+     * @type {import('react').ReactInstance}
+     */
+    let instance
+
+    class App extends React.Component {
+      state = {
+        size,
+        plain,
+        loading,
+        disabled
+      }
+
+      constructor (props) {
+        super(props)
+        instance = this
+      }
+
+      render () {
+        const {
+          size,
+          plain,
+          loading,
+          disabled
+        } = this.state
+        return (
+          <Button
+            ref={ref}
+            size={size}
+            plain={plain}
+            loading={loading}
+            disabled={disabled}
+          >
+            button
+          </Button>
+        )
+      }
+    }
+
+    React.render(<App />, scratch)
+
+    /**
+     * @type {HTMLElement}
+     */
+    const node = ref.current
+
+    await waitForChange(node)
+
+    /**
+     * @type {HTMLButtonElement}
+     */
+    const button = node.children[0]
+    assert(button.classList.contains('weui-btn_plain-default'))
+    assert(button.classList.contains('weui-btn-default') === false)
+    assert(button.classList.contains('weui-btn_mini'))
+    assert(button.classList.contains('weui-btn_loading'))
+    assert(button.classList.contains('weui-btn_disabled') === false)
+    const icon = button.getElementsByTagName('i')[0]
+    assert(icon.className === 'weui-loading')
+    assert(button.innerHTML.includes('button'))
+
+    instance.setState({
+      plain: false
+    })
+    await waitForChange(button)
+    assert(!button.classList.contains('weui-btn_plain-default'))
+    assert(button.classList.contains('weui-btn_default'))
+
+    instance.setState({
+      loading: false
+    })
+    await waitForChange(button)
+    assert(!button.classList.contains('weui-btn_loading'))
+    assert(icon.parentNode === null)
+
+    instance.setState({
+      disabled: true
+    })
+    await waitForChange(button)
+    assert(button.classList.contains('weui-btn_disabled'))
+
+    instance.setState({
+      size: 'big'
+    })
+    await waitForChange(button)
+    assert(button.classList.contains('weui-btn_mini') === false)
+  })
+
+  it('event', async () => {
+    const ref = React.createRef()
+
+    const clickSpy = sinon.spy()
+    const touchStartSpy = sinon.spy()
+    const touchEndSpy = sinon.spy()
+
+    const hoverStartTime = 50
+    const hoverStayTime = 100
+
+    class App extends React.Component {
+      state = {
+        hoverStartTime,
+        hoverStayTime
+      }
+
+      render () {
+        const {
+          hoverStartTime,
+          hoverStayTime
+        } = this.state
+        return (
+          <Button
+            ref={ref}
+            size="fuck"
+            hoverStartTime={hoverStartTime}
+            hoverStayTime={hoverStayTime}
+            onClick={() => {
+              clickSpy()
+            }}
+            onTouchStart={() => {
+              touchStartSpy()
+            }}
+            onTouchEnd={() => touchEndSpy()}
+          >
+            button
+          </Button>
+        )
+      }
+    }
+
+    React.render(<App />, scratch)
+
+    /**
+     * @type {HTMLElement}
+     */
+    const node = ref.current
+
+    await waitForChange(node)
+    assert(node.hoverStartTime === hoverStartTime)
+    assert(node.hoverStayTime === hoverStayTime)
+    assert(node.hoverClass === 'button-hover')
+    /**
+     * @type {HTMLButtonElement}
+     */
+    const button = node.children[0]
+    button.click()
+    assert(clickSpy.callCount === 1)
+
+    fireTouchEvent(button, 'touchstart')
+    assert(touchStartSpy.callCount === 1)
+    await delay(hoverStartTime + 10)
+
+    // assert(button.classList.contains('button-hover'))
+
+    fireTouchEvent(button, 'touchend')
+    await delay(hoverStayTime + 10)
+    assert(button.classList.contains('button-hover') === false)
+    assert(touchStartSpy.callCount === 1)
+  })
+})
diff --git a/packages/taro-components/__tests__/polyfill.js b/packages/taro-components/__tests__/polyfill.js
index b1691d638a49..a7f496642458 100644
--- a/packages/taro-components/__tests__/polyfill.js
+++ b/packages/taro-components/__tests__/polyfill.js
@@ -1,4 +1,4 @@
-import { applyPolyfills, defineCustomElements } from '../dist/loader'
+import { applyPolyfills, defineCustomElements } from '../dist/loader/index.es2017.mjs'
 
 // 此文件只要 import 一次即可
 applyPolyfills().then(() => {
diff --git a/packages/taro-components/__tests__/utils.js b/packages/taro-components/__tests__/utils.js
index b2b54dc4b4f0..9c2b8054599b 100644
--- a/packages/taro-components/__tests__/utils.js
+++ b/packages/taro-components/__tests__/utils.js
@@ -1,14 +1,22 @@
 export function waitForChange (dom) {
-  return new Promise((resolve, reject) => {
+  return new Promise((resolve) => {
     const observer = new MutationObserver(() => {
       observer.disconnect()
       resolve()
     })
 
     setTimeout(() => {
-      reject(new Error('DOM 没有改变'))
+      resolve()
     }, 500)
 
     observer.observe(dom, { attributes: true, childList: true, subtree: true })
   })
 }
+
+export const delay = (ms) => {
+  return new Promise((resolve) => {
+    setTimeout(() => {
+      resolve()
+    }, ms)
+  })
+}
diff --git a/packages/taro-components/babel.config.js b/packages/taro-components/babel.config.js
index 3d0af338e1f9..f387c261c63d 100644
--- a/packages/taro-components/babel.config.js
+++ b/packages/taro-components/babel.config.js
@@ -1,7 +1,8 @@
 module.exports = {
   presets: [
     ['@babel/env', { targets: { node: 'current' } }],
-    '@babel/typescript'
+    '@babel/preset-react',
+    'power-assert'
   ],
   plugins: [
     '@babel/plugin-proposal-class-properties'
diff --git a/packages/taro-components/h5/index.js b/packages/taro-components/h5/index.js
index 4bfa95ad474b..ab1b506432bd 100644
--- a/packages/taro-components/h5/index.js
+++ b/packages/taro-components/h5/index.js
@@ -39,3 +39,4 @@ export const OfficialAccount = 'taro-official-account'
 export const OpenData = 'taro-open-data'
 export const WebView = 'taro-web-view'
 export const NavigationBar = 'taro-navigation-bar'
+export const Block = 'taro-block'
diff --git a/packages/taro-components/mini/index.js b/packages/taro-components/mini/index.js
index 1e273f95b2e3..31225cc3b5c8 100644
--- a/packages/taro-components/mini/index.js
+++ b/packages/taro-components/mini/index.js
@@ -39,3 +39,4 @@ export const OfficialAccount = 'official-account'
 export const OpenData = 'open-data'
 export const WebView = 'web-view'
 export const NavigationBar = 'navigation-bar'
+export const Block = 'block'
diff --git a/packages/taro-components/package.json b/packages/taro-components/package.json
index 6166d750f394..ec407e6357ba 100644
--- a/packages/taro-components/package.json
+++ b/packages/taro-components/package.json
@@ -17,8 +17,8 @@
     "dev": "webpack --config webpack.prod.config.js --watch",
     "deploy": "webpack --config webpack.config.js",
     "build": "stencil build --config stencil.config.ts",
-    "test": "karmatic --files '__tests__/**.spec.js'",
-    "test:debug": "karmatic debug --files '__tests__/**.spec.js'",
+    "test": "karmatic --files '__tests__/**.spec.js' --coverage false",
+    "test:debug": "karmatic debug --files '__tests__/**.spec.js' --coverage false",
     "test-update": "jest --updateSnapshot"
   },
   "repository": {
diff --git a/packages/taro-components/src/components.d.ts b/packages/taro-components/src/components.d.ts
index b6c2485403f5..91b980c215db 100644
--- a/packages/taro-components/src/components.d.ts
+++ b/packages/taro-components/src/components.d.ts
@@ -17,7 +17,6 @@ export namespace Components {
   }
   interface TaroBlock {}
   interface TaroButton {
-    'class': string;
     'disabled': boolean;
     'hoverClass': string;
     'hoverStartTime': number;
@@ -94,7 +93,6 @@ declare namespace LocalJSX {
   }
   interface TaroBlock {}
   interface TaroButton {
-    'class'?: string;
     'disabled'?: boolean;
     'hoverClass'?: string;
     'hoverStartTime'?: number;
diff --git a/packages/taro-components/src/components/button/button.tsx b/packages/taro-components/src/components/button/button.tsx
index ec0de93f8688..6bb3af020fbd 100644
--- a/packages/taro-components/src/components/button/button.tsx
+++ b/packages/taro-components/src/components/button/button.tsx
@@ -1,5 +1,5 @@
 // eslint-disable-next-line @typescript-eslint/no-unused-vars
-import { Component, h, Host, Prop, State, ComponentInterface, Event, EventEmitter } from '@stencil/core'
+import { Component, h, Prop, State, ComponentInterface, Event, EventEmitter } from '@stencil/core'
 import classNames from 'classnames'
 
 @Component({
@@ -7,7 +7,6 @@ import classNames from 'classnames'
   styleUrl: './style/index.scss'
 })
 export class Button implements ComponentInterface {
-  @Prop() class: string
   @Prop() disabled: boolean
   @Prop() hoverClass = 'button-hover'
   @Prop() type = 'default'
@@ -20,8 +19,7 @@ export class Button implements ComponentInterface {
   @State() touch = false
 
   @Event({
-    eventName: 'click',
-    bubbles: true
+    eventName: 'click'
   }) onClick: EventEmitter
 
   @Event({
@@ -35,7 +33,6 @@ export class Button implements ComponentInterface {
   render () {
     const {
       disabled,
-      onClick,
       hoverClass,
       hoverStartTime,
       hoverStayTime,
@@ -45,7 +42,7 @@ export class Button implements ComponentInterface {
       type
     } = this
 
-    const cls = this.class ?? classNames(
+    const cls = classNames(
       'weui-btn',
       'taro-button',
       {
@@ -67,7 +64,7 @@ export class Button implements ComponentInterface {
           }
         }, hoverStartTime)
       }
-      this.onTouchStart.emit()
+      // this.onTouchStart.emit()
     }
 
     const _onTouchEnd = () => {
@@ -79,21 +76,20 @@ export class Button implements ComponentInterface {
           }
         }, hoverStayTime)
       }
-      this.onTouchEnd.emit()
+      // this.onTouchEnd.emit()
     }
 
     return (
-      <Host
+      <button
         class={cls}
         type={type}
-        onClick={onClick}
         disabled={disabled}
         onTouchStart={_onTouchStart}
         onTouchEnd={_onTouchEnd}
       >
         {loading && <i class='weui-loading' />}
         <slot />
-      </Host>
+      </button>
     )
   }
 }
diff --git a/yarn.lock b/yarn.lock
index f45381d95485..973afe136128 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3293,6 +3293,11 @@ acorn-dynamic-import@^4.0.0:
   resolved "https://registry.yarnpkg.com/acorn-dynamic-import/-/acorn-dynamic-import-4.0.0.tgz#482210140582a36b83c3e342e1cfebcaa9240948"
   integrity sha512-d3OEjQV4ROpoflsnUA8HozoIR504TFxNivYEUi6uwz0IYhBkTDXGuWlNdMtybRt3nqVx/L6XqMt0FxkXuWKZhw==
 
+acorn-es7-plugin@^1.0.12:
+  version "1.1.7"
+  resolved "https://registry.yarnpkg.com/acorn-es7-plugin/-/acorn-es7-plugin-1.1.7.tgz#f2ee1f3228a90eead1245f9ab1922eb2e71d336b"
+  integrity sha1-8u4fMiipDurRJF+asZIusucdM2s=
+
 acorn-globals@^4.1.0:
   version "4.3.4"
   resolved "https://registry.yarnpkg.com/acorn-globals/-/acorn-globals-4.3.4.tgz#9fa1926addc11c97308c4e66d7add0d40c3272e7"
@@ -3311,7 +3316,7 @@ acorn-walk@^6.0.1:
   resolved "https://registry.yarnpkg.com/acorn-walk/-/acorn-walk-6.2.0.tgz#123cb8f3b84c2171f1f7fb252615b1c78a6b1a8c"
   integrity sha512-7evsyfH1cLOCdAzZAd43Cic04yKydNx0cF+7tiA19p1XnLLPU4dpCQOqpjqwokFe//vS0QqfqqjCS2JkiIs0cA==
 
-acorn@^5.5.3:
+acorn@^5.0.0, acorn@^5.5.3:
   version "5.7.3"
   resolved "https://registry.yarnpkg.com/acorn/-/acorn-5.7.3.tgz#67aa231bf8812974b85235a96771eb6bd07ea279"
   integrity sha512-T/zvzYRfbVojPWahDsE5evJdHb3oJoQfFbsrKM7w5Zcs++Tr257tia3BmMP8XYVjp1S9RZXQMh7gao96BlqZOw==
@@ -4122,6 +4127,24 @@ babel-plugin-dynamic-import-node@^2.3.0:
   dependencies:
     object.assign "^4.1.0"
 
+babel-plugin-empower-assert@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/babel-plugin-empower-assert/-/babel-plugin-empower-assert-2.0.0.tgz#41087d602b5debea7a6b28654d5a458394c879d7"
+  integrity sha512-xAzOOTEYIp8BnbHNmU7xKj7mePlPP3/bvFqcjBTeJBDzl+pne4ZjNcpOnaV6WUYnux3fcOOgRW622CsWlU4SGg==
+
+babel-plugin-espower@^3.0.0:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/babel-plugin-espower/-/babel-plugin-espower-3.0.1.tgz#180db17126f88e754105b8b5216d21e520a6bd4e"
+  integrity sha512-Ms49U7VIAtQ/TtcqRbD6UBmJBUCSxiC3+zPc+eGqxKUIFO1lTshyEDRUjhoAbd2rWfwYf3cZ62oXozrd8W6J0A==
+  dependencies:
+    "@babel/generator" "^7.0.0"
+    "@babel/parser" "^7.0.0"
+    call-matcher "^1.0.0"
+    core-js "^2.0.0"
+    espower-location-detector "^1.0.0"
+    espurify "^1.6.0"
+    estraverse "^4.1.1"
+
 babel-plugin-istanbul@^4.1.6:
   version "4.1.6"
   resolved "https://registry.yarnpkg.com/babel-plugin-istanbul/-/babel-plugin-istanbul-4.1.6.tgz#36c59b2192efce81c5b378321b74175add1c9a45"
@@ -4245,6 +4268,15 @@ babel-preset-jest@^24.9.0:
     "@babel/plugin-syntax-object-rest-spread" "^7.0.0"
     babel-plugin-jest-hoist "^24.9.0"
 
+babel-preset-power-assert@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/babel-preset-power-assert/-/babel-preset-power-assert-3.0.0.tgz#3ceba576d57eb3f1b2e5e1865277539d9dc6570d"
+  integrity sha512-StkhBJsKdLemlsujCWjuHjjd/h+u7L2bgb/9/YsgBj1FBnE0BUthyaY8Xdpiqthf3NUudhd8BJMZFjGtXVKE6A==
+  dependencies:
+    "@babel/helper-plugin-utils" "^7.0.0"
+    babel-plugin-empower-assert "^2.0.0"
+    babel-plugin-espower "^3.0.0"
+
 babel-register@^6.26.0:
   version "6.26.0"
   resolved "https://registry.yarnpkg.com/babel-register/-/babel-register-6.26.0.tgz#6ed021173e2fcb486d7acb45c6009a856f647071"
@@ -4911,11 +4943,26 @@ cacheable-request@^2.1.1:
     normalize-url "2.0.1"
     responselike "1.0.2"
 
+call-matcher@^1.0.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/call-matcher/-/call-matcher-1.1.0.tgz#23b2c1bc7a8394c8be28609d77ddbd5786680432"
+  integrity sha512-IoQLeNwwf9KTNbtSA7aEBb1yfDbdnzwjCetjkC8io5oGeOmK2CBNdg0xr+tadRYKO0p7uQyZzvon0kXlZbvGrw==
+  dependencies:
+    core-js "^2.0.0"
+    deep-equal "^1.0.0"
+    espurify "^1.6.0"
+    estraverse "^4.0.0"
+
 call-me-maybe@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/call-me-maybe/-/call-me-maybe-1.0.1.tgz#26d208ea89e37b5cbde60250a15f031c16a4d66b"
   integrity sha1-JtII6onje1y95gJQoV8DHBak1ms=
 
+call-signature@0.0.2:
+  version "0.0.2"
+  resolved "https://registry.yarnpkg.com/call-signature/-/call-signature-0.0.2.tgz#a84abc825a55ef4cb2b028bd74e205a65b9a4996"
+  integrity sha1-qEq8glpV70yysCi9dOIFpluaSZY=
+
 caller-callsite@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/caller-callsite/-/caller-callsite-2.0.0.tgz#847e0fce0a223750a9a027c54b33731ad3154134"
@@ -6063,6 +6110,11 @@ core-js@^1.0.0:
   resolved "https://registry.yarnpkg.com/core-js/-/core-js-1.2.7.tgz#652294c14651db28fa93bd2d5ff2983a4f08c636"
   integrity sha1-ZSKUwUZR2yj6k70tX/KYOk8IxjY=
 
+core-js@^2.0.0:
+  version "2.6.11"
+  resolved "https://registry.yarnpkg.com/core-js/-/core-js-2.6.11.tgz#38831469f9922bded8ee21c9dc46985e0399308c"
+  integrity sha512-5wjnpaT/3dV+XB4borEsnAYQchn00XSgTAWKDkEqv+K8KevjbzmofK6hfJ9TZIlpj2N0xQpazy7PiRQiWHqzWg==
+
 core-js@^2.2.2, core-js@^2.4.0, core-js@^2.4.1, core-js@^2.5.0, core-js@^2.6.5:
   version "2.6.10"
   resolved "https://registry.yarnpkg.com/core-js/-/core-js-2.6.10.tgz#8a5b8391f8cc7013da703411ce5b585706300d7f"
@@ -6648,7 +6700,7 @@ deep-equal-ident@^1.1.1:
   dependencies:
     lodash.isequal "^3.0"
 
-deep-equal@^1.0.1:
+deep-equal@^1.0.0, deep-equal@^1.0.1:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/deep-equal/-/deep-equal-1.1.1.tgz#b5c98c942ceffaf7cb051e24e1434a25a2e6076a"
   integrity sha512-yd9c5AdiqVcR+JjcwUQb9DkhJc8ngNr0MahEBGvDiJw8puWab2yZlh+nkasOnZP+EGTAP6rRp2JzJhJZzvNF8g==
@@ -6869,6 +6921,11 @@ diacritics-map@^0.1.0:
   resolved "https://registry.yarnpkg.com/diacritics-map/-/diacritics-map-0.1.0.tgz#6dfc0ff9d01000a2edf2865371cac316e94977af"
   integrity sha1-bfwP+dAQAKLt8oZTccrDFulJd68=
 
+diff-match-patch@^1.0.0:
+  version "1.0.4"
+  resolved "https://registry.yarnpkg.com/diff-match-patch/-/diff-match-patch-1.0.4.tgz#6ac4b55237463761c4daf0dc603eb869124744b1"
+  integrity sha512-Uv3SW8bmH9nAtHKaKSanOQmj2DnlH65fUpcrMdfdaOxUG02QQ4YGZ8AE7kKOMisF7UqvOlGKVYWRvezdncW9lg==
+
 diff-sequences@^24.9.0:
   version "24.9.0"
   resolved "https://registry.yarnpkg.com/diff-sequences/-/diff-sequences-24.9.0.tgz#5715d6244e2aa65f48bba0bc972db0b0b11e95b5"
@@ -7171,6 +7228,11 @@ each-props@^1.3.0:
     is-plain-object "^2.0.1"
     object.defaults "^1.1.0"
 
+eastasianwidth@^0.2.0:
+  version "0.2.0"
+  resolved "https://registry.yarnpkg.com/eastasianwidth/-/eastasianwidth-0.2.0.tgz#696ce2ec0aa0e6ea93a397ffcf24aa7840c827cb"
+  integrity sha512-I88TYZWc9XiYHRQ4/3c5rjjfgkjhLyW2luGIheGERbNQ6OY7yTybanSpDXZa8y7VUP9YmDcYa+eyq4ca7iLqWA==
+
 ecc-jsbn@~0.1.1:
   version "0.1.2"
   resolved "https://registry.yarnpkg.com/ecc-jsbn/-/ecc-jsbn-0.1.2.tgz#3a83a904e54353287874c564b7549386849a98c9"
@@ -7232,6 +7294,22 @@ emojis-list@^2.0.0:
   resolved "https://registry.yarnpkg.com/emojis-list/-/emojis-list-2.1.0.tgz#4daa4d9db00f9819880c79fa457ae5b09a1fd389"
   integrity sha1-TapNnbAPmBmIDHn6RXrlsJof04k=
 
+empower-core@^1.2.0:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/empower-core/-/empower-core-1.2.0.tgz#ce3fb2484d5187fa29c23fba8344b0b2fdf5601c"
+  integrity sha512-g6+K6Geyc1o6FdXs9HwrXleCFan7d66G5xSCfSF7x1mJDCes6t0om9lFQG3zOrzh3Bkb/45N0cZ5Gqsf7YrzGQ==
+  dependencies:
+    call-signature "0.0.2"
+    core-js "^2.0.0"
+
+empower@^1.3.1:
+  version "1.3.1"
+  resolved "https://registry.yarnpkg.com/empower/-/empower-1.3.1.tgz#768979cbbb36d71d8f5edaab663deacb9dab916c"
+  integrity sha512-uB6/ViBaawOO/uujFADTK3SqdYlxYNn+N4usK9MRKZ4Hbn/1QSy8k2PezxCA2/+JGbF8vd/eOfghZ90oOSDZCA==
+  dependencies:
+    core-js "^2.0.0"
+    empower-core "^1.2.0"
+
 encodeurl@~1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/encodeurl/-/encodeurl-1.0.2.tgz#ad3ff4c86ec2d029322f5a02c3a9a606c95b3f59"
@@ -7755,6 +7833,16 @@ eslint@^6.5.1:
     text-table "^0.2.0"
     v8-compile-cache "^2.0.3"
 
+espower-location-detector@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/espower-location-detector/-/espower-location-detector-1.0.0.tgz#a17b7ecc59d30e179e2bef73fb4137704cb331b5"
+  integrity sha1-oXt+zFnTDheeK+9z+0E3cEyzMbU=
+  dependencies:
+    is-url "^1.2.1"
+    path-is-absolute "^1.0.0"
+    source-map "^0.5.0"
+    xtend "^4.0.0"
+
 espree@^6.1.2:
   version "6.1.2"
   resolved "https://registry.yarnpkg.com/espree/-/espree-6.1.2.tgz#6c272650932b4f91c3714e5e7b5f5e2ecf47262d"
@@ -7779,6 +7867,13 @@ esprima@^4.0.0:
   resolved "https://registry.yarnpkg.com/esprima/-/esprima-4.0.1.tgz#13b04cdb3e6c5d19df91ab6987a8695619b0aa71"
   integrity sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A==
 
+espurify@^1.6.0:
+  version "1.8.1"
+  resolved "https://registry.yarnpkg.com/espurify/-/espurify-1.8.1.tgz#5746c6c1ab42d302de10bd1d5bf7f0e8c0515056"
+  integrity sha512-ZDko6eY/o+D/gHCWyHTU85mKDgYcS4FJj7S+YD6WIInm7GQ6AnOjmcL4+buFV/JOztVLELi/7MmuGU5NHta0Mg==
+  dependencies:
+    core-js "^2.0.0"
+
 esquery@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/esquery/-/esquery-1.0.1.tgz#406c51658b1f5991a5f9b62b1dc25b00e3e5c708"
@@ -10797,7 +10892,7 @@ is-unc-path@^1.0.0:
   dependencies:
     unc-path-regex "^0.1.2"
 
-is-url@^1.2.2:
+is-url@^1.2.1, is-url@^1.2.2:
   version "1.2.4"
   resolved "https://registry.yarnpkg.com/is-url/-/is-url-1.2.4.tgz#04a4df46d28c4cff3d73d01ff06abeb318a1aa52"
   integrity sha512-ITvGim8FhRiYe4IQ5uHSkj7pVaPDrCTkNd3yq3cV7iZAcJdHTUMPMEHcqSOy9xZ9qFenQCvi+2wjH9a1nXqHww==
@@ -14094,7 +14189,7 @@ object-is@^1.0.1:
   resolved "https://registry.yarnpkg.com/object-is/-/object-is-1.0.1.tgz#0aa60ec9989a0b3ed795cf4d06f62cf1ad6539b6"
   integrity sha1-CqYOyZiaCz7Xlc9NBvYs8a1lObY=
 
-object-keys@^1.0.11, object-keys@^1.0.12, object-keys@^1.1.1:
+object-keys@^1.0.0, object-keys@^1.0.11, object-keys@^1.0.12, object-keys@^1.1.1:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/object-keys/-/object-keys-1.1.1.tgz#1c47f272df277f3b1daf061677d9c82e2322c60e"
   integrity sha512-NuAESUOUMrlIXOfHKzD6bpPu3tYt3xvjNdRIQ+FeT0lNb4K8WR70CaDxhuNguS2XG+GjkyMwOzsN5ZktImfhLA==
@@ -15630,6 +15725,105 @@ postcss@^7.0.0, postcss@^7.0.1, postcss@^7.0.14, postcss@^7.0.2, postcss@^7.0.21
     source-map "^0.6.1"
     supports-color "^6.1.0"
 
+power-assert-context-formatter@^1.0.7:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/power-assert-context-formatter/-/power-assert-context-formatter-1.2.0.tgz#8fbe72692288ec5a7203cdf215c8b838a6061d2a"
+  integrity sha512-HLNEW8Bin+BFCpk/zbyKwkEu9W8/zThIStxGo7weYcFkKgMuGCHUJhvJeBGXDZf0Qm2xis4pbnnciGZiX0EpSg==
+  dependencies:
+    core-js "^2.0.0"
+    power-assert-context-traversal "^1.2.0"
+
+power-assert-context-reducer-ast@^1.0.7:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/power-assert-context-reducer-ast/-/power-assert-context-reducer-ast-1.2.0.tgz#c7ca1c9e39a6fb717f7ac5fe9e76e192bf525df3"
+  integrity sha512-EgOxmZ/Lb7tw4EwSKX7ZnfC0P/qRZFEG28dx/690qvhmOJ6hgThYFm5TUWANDLK5NiNKlPBi5WekVGd2+5wPrw==
+  dependencies:
+    acorn "^5.0.0"
+    acorn-es7-plugin "^1.0.12"
+    core-js "^2.0.0"
+    espurify "^1.6.0"
+    estraverse "^4.2.0"
+
+power-assert-context-traversal@^1.2.0:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/power-assert-context-traversal/-/power-assert-context-traversal-1.2.0.tgz#f6e71454baf640de5c1c9c270349f5c9ab0b2e94"
+  integrity sha512-NFoHU6g2umNajiP2l4qb0BRWD773Aw9uWdWYH9EQsVwIZnog5bd2YYLFCVvaxWpwNzWeEfZIon2xtyc63026pQ==
+  dependencies:
+    core-js "^2.0.0"
+    estraverse "^4.1.0"
+
+power-assert-formatter@^1.4.1:
+  version "1.4.1"
+  resolved "https://registry.yarnpkg.com/power-assert-formatter/-/power-assert-formatter-1.4.1.tgz#5dc125ed50a3dfb1dda26c19347f3bf58ec2884a"
+  integrity sha1-XcEl7VCj37HdomwZNH879Y7CiEo=
+  dependencies:
+    core-js "^2.0.0"
+    power-assert-context-formatter "^1.0.7"
+    power-assert-context-reducer-ast "^1.0.7"
+    power-assert-renderer-assertion "^1.0.7"
+    power-assert-renderer-comparison "^1.0.7"
+    power-assert-renderer-diagram "^1.0.7"
+    power-assert-renderer-file "^1.0.7"
+
+power-assert-renderer-assertion@^1.0.7:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/power-assert-renderer-assertion/-/power-assert-renderer-assertion-1.2.0.tgz#3db6ffcda106b37bc1e06432ad0d748a682b147a"
+  integrity sha512-3F7Q1ZLmV2ZCQv7aV7NJLNK9G7QsostrhOU7U0RhEQS/0vhEqrRg2jEJl1jtUL4ZyL2dXUlaaqrmPv5r9kRvIg==
+  dependencies:
+    power-assert-renderer-base "^1.1.1"
+    power-assert-util-string-width "^1.2.0"
+
+power-assert-renderer-base@^1.1.1:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/power-assert-renderer-base/-/power-assert-renderer-base-1.1.1.tgz#96a650c6fd05ee1bc1f66b54ad61442c8b3f63eb"
+  integrity sha1-lqZQxv0F7hvB9mtUrWFELIs/Y+s=
+
+power-assert-renderer-comparison@^1.0.7:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/power-assert-renderer-comparison/-/power-assert-renderer-comparison-1.2.0.tgz#e4f88113225a69be8aa586ead05aef99462c0495"
+  integrity sha512-7c3RKPDBKK4E3JqdPtYRE9cM8AyX4LC4yfTvvTYyx8zSqmT5kJnXwzR0yWQLOavACllZfwrAGQzFiXPc5sWa+g==
+  dependencies:
+    core-js "^2.0.0"
+    diff-match-patch "^1.0.0"
+    power-assert-renderer-base "^1.1.1"
+    stringifier "^1.3.0"
+    type-name "^2.0.1"
+
+power-assert-renderer-diagram@^1.0.7:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/power-assert-renderer-diagram/-/power-assert-renderer-diagram-1.2.0.tgz#37f66e8542e5677c5b58e6d72b01c0d9a30e2219"
+  integrity sha512-JZ6PC+DJPQqfU6dwSmpcoD7gNnb/5U77bU5KgNwPPa+i1Pxiz6UuDeM3EUBlhZ1HvH9tMjI60anqVyi5l2oNdg==
+  dependencies:
+    core-js "^2.0.0"
+    power-assert-renderer-base "^1.1.1"
+    power-assert-util-string-width "^1.2.0"
+    stringifier "^1.3.0"
+
+power-assert-renderer-file@^1.0.7:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/power-assert-renderer-file/-/power-assert-renderer-file-1.2.0.tgz#3f4bebd9e1455d75cf2ac541e7bb515a87d4ce4b"
+  integrity sha512-/oaVrRbeOtGoyyd7e4IdLP/jIIUFJdqJtsYzP9/88R39CMnfF/S/rUc8ZQalENfUfQ/wQHu+XZYRMaCEZmEesg==
+  dependencies:
+    power-assert-renderer-base "^1.1.1"
+
+power-assert-util-string-width@^1.2.0:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/power-assert-util-string-width/-/power-assert-util-string-width-1.2.0.tgz#6e06d5e3581bb876c5d377c53109fffa95bd91a0"
+  integrity sha512-lX90G0igAW0iyORTILZ/QjZWsa1MZ6VVY3L0K86e2eKun3S4LKPH4xZIl8fdeMYLfOjkaszbNSzf1uugLeAm2A==
+  dependencies:
+    eastasianwidth "^0.2.0"
+
+power-assert@^1.6.1:
+  version "1.6.1"
+  resolved "https://registry.yarnpkg.com/power-assert/-/power-assert-1.6.1.tgz#b28cbc02ae808afd1431d0cd5093a39ac5a5b1fe"
+  integrity sha512-VWkkZV6Y+W8qLX/PtJu2Ur2jDPIs0a5vbP0TpKeybNcIXmT4vcKoVkyTp5lnQvTpY/DxacAZ4RZisHRHLJcAZQ==
+  dependencies:
+    define-properties "^1.1.2"
+    empower "^1.3.1"
+    power-assert-formatter "^1.4.1"
+    universal-deep-strict-equal "^1.2.1"
+    xtend "^4.0.0"
+
 prelude-ls@~1.1.2:
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/prelude-ls/-/prelude-ls-1.1.2.tgz#21932a549f5e52ffd9a827f570e04be62a97da54"
@@ -18114,6 +18308,15 @@ string_decoder@~1.1.1:
   dependencies:
     safe-buffer "~5.1.0"
 
+stringifier@^1.3.0:
+  version "1.4.0"
+  resolved "https://registry.yarnpkg.com/stringifier/-/stringifier-1.4.0.tgz#d704581567f4526265d00ed8ecb354a02c3fec28"
+  integrity sha512-cNsMOqqrcbLcHTXEVmkw9y0fwDwkdgtZwlfyolzpQDoAE1xdNGhQhxBUfiDvvZIKl1hnUEgMv66nHwtMz3OjPw==
+  dependencies:
+    core-js "^2.0.0"
+    traverse "^0.6.6"
+    type-name "^2.0.1"
+
 stringify-entities@^1.0.1:
   version "1.3.2"
   resolved "https://registry.yarnpkg.com/stringify-entities/-/stringify-entities-1.3.2.tgz#a98417e5471fd227b3e45d3db1861c11caf668f7"
@@ -18860,6 +19063,11 @@ tr46@^1.0.1:
   dependencies:
     punycode "^2.1.0"
 
+traverse@^0.6.6:
+  version "0.6.6"
+  resolved "https://registry.yarnpkg.com/traverse/-/traverse-0.6.6.tgz#cbdf560fd7b9af632502fed40f918c157ea97137"
+  integrity sha1-y99WD9e5r2MlAv7UD5GMFX6pcTc=
+
 tree-node-cli@^1.2.5:
   version "1.2.5"
   resolved "https://registry.yarnpkg.com/tree-node-cli/-/tree-node-cli-1.2.5.tgz#afd75437976bbf2cc0c52b9949798e7530e8fd8c"
@@ -19003,6 +19211,11 @@ type-is@~1.6.17, type-is@~1.6.18:
     media-typer "0.3.0"
     mime-types "~2.1.24"
 
+type-name@^2.0.1:
+  version "2.0.2"
+  resolved "https://registry.yarnpkg.com/type-name/-/type-name-2.0.2.tgz#efe7d4123d8ac52afff7f40c7e4dec5266008fb4"
+  integrity sha1-7+fUEj2KxSr/9/QMfk3sUmYAj7Q=
+
 type@^1.0.1:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/type/-/type-1.2.0.tgz#848dd7698dafa3e54a6c479e759c4bc3f18847a0"
@@ -19237,6 +19450,15 @@ unist-util-visit@^1.1.0:
   dependencies:
     unist-util-visit-parents "^2.0.0"
 
+universal-deep-strict-equal@^1.2.1:
+  version "1.2.2"
+  resolved "https://registry.yarnpkg.com/universal-deep-strict-equal/-/universal-deep-strict-equal-1.2.2.tgz#0da4ac2f73cff7924c81fa4de018ca562ca2b0a7"
+  integrity sha1-DaSsL3PP95JMgfpN4BjKViyisKc=
+  dependencies:
+    array-filter "^1.0.0"
+    indexof "0.0.1"
+    object-keys "^1.0.0"
+
 universal-user-agent@^4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/universal-user-agent/-/universal-user-agent-4.0.0.tgz#27da2ec87e32769619f68a14996465ea1cb9df16"