diff --git a/app/javascript/mastodon/components/animated_number.jsx b/app/javascript/mastodon/components/animated_number.jsx
deleted file mode 100644
index ce688f04f..000000000
--- a/app/javascript/mastodon/components/animated_number.jsx
+++ /dev/null
@@ -1,76 +0,0 @@
-import React from 'react';
-import PropTypes from 'prop-types';
-import ShortNumber from 'mastodon/components/short_number';
-import TransitionMotion from 'react-motion/lib/TransitionMotion';
-import spring from 'react-motion/lib/spring';
-import { reduceMotion } from 'mastodon/initial_state';
-
-const obfuscatedCount = count => {
- if (count < 0) {
- return 0;
- } else if (count <= 1) {
- return count;
- } else {
- return '1+';
- }
-};
-
-export default class AnimatedNumber extends React.PureComponent {
-
- static propTypes = {
- value: PropTypes.number.isRequired,
- obfuscate: PropTypes.bool,
- };
-
- state = {
- direction: 1,
- };
-
- componentWillReceiveProps (nextProps) {
- if (nextProps.value > this.props.value) {
- this.setState({ direction: 1 });
- } else if (nextProps.value < this.props.value) {
- this.setState({ direction: -1 });
- }
- }
-
- willEnter = () => {
- const { direction } = this.state;
-
- return { y: -1 * direction };
- };
-
- willLeave = () => {
- const { direction } = this.state;
-
- return { y: spring(1 * direction, { damping: 35, stiffness: 400 }) };
- };
-
- render () {
- const { value, obfuscate } = this.props;
- const { direction } = this.state;
-
- if (reduceMotion) {
- return obfuscate ? obfuscatedCount(value) : ;
- }
-
- const styles = [{
- key: `${value}`,
- data: value,
- style: { y: spring(0, { damping: 35, stiffness: 400 }) },
- }];
-
- return (
-
- {items => (
-
- {items.map(({ key, data, style }) => (
- 0 ? 'absolute' : 'static', transform: `translateY(${style.y * 100}%)` }}>{obfuscate ? obfuscatedCount(data) : }
- ))}
-
- )}
-
- );
- }
-
-}
diff --git a/app/javascript/mastodon/components/animated_number.tsx b/app/javascript/mastodon/components/animated_number.tsx
new file mode 100644
index 000000000..1673ff41b
--- /dev/null
+++ b/app/javascript/mastodon/components/animated_number.tsx
@@ -0,0 +1,58 @@
+import React, { useCallback, useState } from 'react';
+import ShortNumber from './short_number';
+import { TransitionMotion, spring } from 'react-motion';
+import { reduceMotion } from '../initial_state';
+
+const obfuscatedCount = (count: number) => {
+ if (count < 0) {
+ return 0;
+ } else if (count <= 1) {
+ return count;
+ } else {
+ return '1+';
+ }
+};
+
+type Props = {
+ value: number;
+ obfuscate?: boolean;
+}
+export const AnimatedNumber: React.FC = ({
+ value,
+ obfuscate,
+})=> {
+ const [previousValue, setPreviousValue] = useState(value);
+ const [direction, setDirection] = useState<1|-1>(1);
+
+ if (previousValue !== value) {
+ setPreviousValue(value);
+ setDirection(value > previousValue ? 1 : -1);
+ }
+
+ const willEnter = useCallback(() => ({ y: -1 * direction }), [direction]);
+ const willLeave = useCallback(() => ({ y: spring(1 * direction, { damping: 35, stiffness: 400 }) }), [direction]);
+
+ if (reduceMotion) {
+ return obfuscate ? <>{obfuscatedCount(value)}> : ;
+ }
+
+ const styles = [{
+ key: `${value}`,
+ data: value,
+ style: { y: spring(0, { damping: 35, stiffness: 400 }) },
+ }];
+
+ return (
+
+ {items => (
+
+ {items.map(({ key, data, style }) => (
+ 0 ? 'absolute' : 'static', transform: `translateY(${style.y * 100}%)` }}>{obfuscate ? obfuscatedCount(data) : }
+ ))}
+
+ )}
+
+ );
+};
+
+export default AnimatedNumber;