chore(TransitionGroup): remove deprecated lifecycle methods

src/lib/index.js

@@ -2,7 +2,6 @@ import makeDebugger from './makeDebugger'
 
 export AutoControlledComponent from './AutoControlledComponent'
 export ModernAutoControlledComponent from './ModernAutoControlledComponent'
-export { getChildMapping, mergeChildMappings } from './childMapping'
 export * as childrenUtils from './childrenUtils'
 
 export {

src/modules/Transition/TransitionGroup.js

@@ -1,16 +1,10 @@
 import _ from 'lodash'
 import PropTypes from 'prop-types'
-import React, { cloneElement, Fragment } from 'react'
-
-import {
-  getChildMapping,
-  getElementType,
-  getUnhandledProps,
-  makeDebugger,
-  mergeChildMappings,
-  SUI,
-} from '../../lib'
-import Transition from './Transition'
+import React from 'react'
+
+import { getElementType, getUnhandledProps, makeDebugger, SUI } from '../../lib'
+import { getChildMapping, mergeChildMappings } from './utils/childMapping'
+import wrapChild from './utils/wrapChild'
 
 const debug = makeDebugger('transition_group')
 
@@ -43,46 +37,72 @@ export default class TransitionGroup extends React.Component {
   }
 
   static defaultProps = {
-    as: Fragment,
+    as: React.Fragment,
     animation: 'fade',
     duration: 500,
   }
 
-  constructor(...args) {
-    super(...args)
+  state = {
+    // Keeping a callback under the state is a hack to make it accessible under getDerivedStateFromProps()
+    handleOnHide: (nothing, childProps) => {
+      debug('handleOnHide', childProps)
+      const { reactKey } = childProps
 
-    const { children } = this.props
-    this.state = {
-      children: _.mapValues(getChildMapping(children), (child) => this.wrapChild(child)),
-    }
+      this.setState((state) => {
+        const children = { ...state.children }
+        delete children[reactKey]
+
+        return { children }
+      })
+    },
   }
 
-  // eslint-disable-next-line camelcase
-  UNSAFE_componentWillReceiveProps(nextProps) {
-    debug('componentWillReceiveProps()')
+  static getDerivedStateFromProps(props, state) {
+    debug('getDerivedStateFromProps()')
+
+    const { animation, duration, directional } = props
+    const { children: prevMapping } = state
+
+    // A short circuit for an initial render as there will be no `prevMapping`
+    if (typeof prevMapping === 'undefined') {
+      return {
+        children: _.mapValues(getChildMapping(props.children), (child) =>
+          wrapChild(child, state.handleOnHide, {
+            animation,
+            duration,
+            directional,
+          }),
+        ),
+      }
+    }
 
-    const { children: prevMapping } = this.state
-    const nextMapping = getChildMapping(nextProps.children)
+    const nextMapping = getChildMapping(props.children)
     const children = mergeChildMappings(prevMapping, nextMapping)
 
     _.forEach(children, (child, key) => {
       const hasPrev = _.has(prevMapping, key)
       const hasNext = _.has(nextMapping, key)
+
       const { [key]: prevChild } = prevMapping
       const isLeaving = !_.get(prevChild, 'props.visible')
 
       // Heads up!
       // An item is new (entering), it will be picked from `nextChildren`, so it should be wrapped
       if (hasNext && (!hasPrev || isLeaving)) {
-        children[key] = this.wrapChild(child, { transitionOnMount: true })
+        children[key] = wrapChild(child, state.handleOnHide, {
+          animation,
+          duration,
+          directional,
+          transitionOnMount: true,
+        })
         return
       }
 
       // Heads up!
       // An item is old (exiting), it will be picked from `prevChildren`, so it has been already
       // wrapped, so should be only updated
       if (!hasNext && hasPrev && !isLeaving) {
-        children[key] = cloneElement(prevChild, { visible: false })
+        children[key] = React.cloneElement(prevChild, { visible: false })
         return
       }
 
@@ -93,43 +113,16 @@ export default class TransitionGroup extends React.Component {
         props: { visible, transitionOnMount },
       } = prevChild
 
-      children[key] = this.wrapChild(child, { transitionOnMount, visible })
+      children[key] = wrapChild(child, state.handleOnHide, {
+        animation,
+        duration,
+        directional,
+        transitionOnMount,
+        visible,
+      })
     })
 
-    this.setState({ children })
-  }
-
-  handleOnHide = (nothing, childProps) => {
-    debug('handleOnHide', childProps)
-    const { reactKey } = childProps
-
-    this.setState((state) => {
-      const children = { ...state.children }
-      delete children[reactKey]
-
-      return { children }
-    })
-  }
-
-  wrapChild = (child, options = {}) => {
-    const { animation, directional, duration } = this.props
-    const { key } = child
-    const { visible = true, transitionOnMount = false } = options
-
-    return (
-      <Transition
-        animation={animation}
-        directional={directional}
-        duration={duration}
-        key={key}
-        onHide={this.handleOnHide}
-        reactKey={key}
-        transitionOnMount={transitionOnMount}
-        visible={visible}
-      >
-        {child}
-      </Transition>
-    )
+    return { children }
   }
 
   render() {

src/modules/Transition/utils/wrapChild.js

@@ -0,0 +1,34 @@
+import React from 'react'
+import Transition from '../Transition'
+
+/**
+ * Wraps a React element with a Transition component.
+ *
+ * @param {React.ReactElement} child
+ * @param {Function} onHide
+ * @param {Object} [options={}]
+ * @param {String} [options.animation]
+ * @param {Number} [options.duration]
+ * @param {Boolean} [options.directional]
+ * @param {Boolean} [options.transitionOnMount=false]
+ * @param {Boolean} [options.visible=true]
+ */
+export default function wrapChild(child, onHide, options = {}) {
+  const { key } = child
+  const { animation, directional, duration, transitionOnMount = false, visible = true } = options
+
+  return (
+    <Transition
+      animation={animation}
+      directional={directional}
+      duration={duration}
+      key={key}
+      onHide={onHide}
+      reactKey={key}
+      transitionOnMount={transitionOnMount}
+      visible={visible}
+    >
+      {child}
+    </Transition>
+  )
+}

test/specs/lib/childMapping-test.js → test/specs/modules/Transition/utils/childMapping-test.js

@@ -1,5 +1,5 @@
 import React from 'react'
-import { getChildMapping, mergeChildMappings } from 'src/lib'
+import { getChildMapping, mergeChildMappings } from 'src/modules/Transition/utils/childMapping'
 
 describe('childMapping', () => {
   describe('childMapping', () => {