Rename JSX files with proper .jsx extension (#23733)

app/javascript/mastodon/features/compose/components/text_icon_button.jsx

@@ -0,0 +1,38 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+
+const iconStyle = {
+  height: null,
+  lineHeight: '27px',
+  width: `${18 * 1.28571429}px`,
+};
+
+export default class TextIconButton extends React.PureComponent {
+
+  static propTypes = {
+    label: PropTypes.string.isRequired,
+    title: PropTypes.string,
+    active: PropTypes.bool,
+    onClick: PropTypes.func.isRequired,
+    ariaControls: PropTypes.string,
+  };
+
+  render () {
+    const { label, title, active, ariaControls } = this.props;
+
+    return (
+      <button
+        type='button'
+        title={title}
+        aria-label={title}
+        className={`text-icon-button ${active ? 'active' : ''}`}
+        aria-expanded={active}
+        onClick={this.props.onClick}
+        aria-controls={ariaControls} style={iconStyle}
+      >
+        {label}
+      </button>
+    );
+  }
+
+}