Use upstream's Icon component

Rework the codebase to avoid unnecessary differences with upstream

app/javascript/flavours/glitch/components/icon.js

@@ -1,26 +1,21 @@
-//  Package imports.
-import classNames from 'classnames';
-import PropTypes from 'prop-types';
 import React from 'react';
+import PropTypes from 'prop-types';
+import classNames from 'classnames';
+
+export default class Icon extends React.PureComponent {
+
+  static propTypes = {
+    id: PropTypes.string.isRequired,
+    className: PropTypes.string,
+    fixedWidth: PropTypes.bool,
+  };
+
+  render () {
+    const { id, className, fixedWidth, ...other } = this.props;
+
+    return (
+      <i role='img' className={classNames('fa', `fa-${id}`, className, { 'fa-fw': fixedWidth })} {...other} />
+    );
+  }
 
-//  This just renders a FontAwesome icon.
-export default function Icon ({
-  className,
-  fullwidth,
-  icon,
-}) {
-  const computedClass = classNames('icon', 'fa', { 'fa-fw': fullwidth }, `fa-${icon}`, className);
-  return icon ? (
-    <span
-      aria-hidden='true'
-      className={computedClass}
-    />
-  ) : null;
 }
-
-//  Props.
-Icon.propTypes = {
-  className: PropTypes.string,
-  fullwidth: PropTypes.bool,
-  icon: PropTypes.string,
-};

app/javascript/flavours/glitch/components/icon_button.js

@@ -3,6 +3,7 @@ import Motion from 'flavours/glitch/util/optional_motion';
 import spring from 'react-motion/lib/spring';
 import PropTypes from 'prop-types';
 import classNames from 'classnames';
+import Icon from 'flavours/glitch/components/icon';
 
 export default class IconButton extends React.PureComponent {
 
@@ -133,7 +134,7 @@ export default class IconButton extends React.PureComponent {
           tabIndex={tabIndex}
           disabled={disabled}
         >
-          <i className={`fa fa-fw fa-${icon}`} aria-hidden='true' />
+          <Icon id={icon} fixedWidth aria-hidden='true' />
         </button>
       );
     }
@@ -155,7 +156,7 @@ export default class IconButton extends React.PureComponent {
             tabIndex={tabIndex}
             disabled={disabled}
           >
-            <i style={{ transform: `rotate(${rotate}deg)` }} className={`fa fa-fw fa-${icon}`} aria-hidden='true' />
+            <Icon id={icon} style={{ transform: `rotate(${rotate}deg)` }} fixedWidth aria-hidden='true' />
             {this.props.label}
           </button>)
         }

app/javascript/flavours/glitch/components/icon_with_badge.js

@@ -6,7 +6,7 @@ const formatNumber = num => num > 40 ? '40+' : num;
 
 const IconWithBadge = ({ id, count, className }) => (
   <i className='icon-with-badge'>
-    <Icon icon={id} fixedWidth className={className} />
+    <Icon id={id} fixedWidth className={className} />
     {count > 0 && <i className='icon-with-badge__badge'>{formatNumber(count)}</i>}
   </i>
 );