1 files changed, 16 insertions, 11 deletions

diff --git a/vnext/src/components/Header.js b/vnext/src/components/Header.js
index fd1c1705..43935f4c 100644
--- a/vnext/src/components/Header.js
+++ b/vnext/src/components/Header.js
@@ -1,6 +1,7 @@
 import React from 'react';
+import PropTypes from 'prop-types';
 
-const elClassHidden = 'header--hidden'
+const elClassHidden = 'header--hidden';
 const elClassBackground = 'header--background';
 
 export default class Header extends React.Component {
@@ -11,7 +12,7 @@ export default class Header extends React.Component {
         this.wScrollCurrent = 0;
         this.wScrollBefore = 0;
         this.wScrollDiff = 0;
-        this.header = React.createRef()
+        this.header = React.createRef();
     }
     componentDidMount() {
         const header = this.header.current;
@@ -23,21 +24,21 @@ export default class Header extends React.Component {
 
             if (this.wScrollCurrent <= 0) {
                 // scrolled to the very top; element sticks to the top
-                header.classList.remove(elClassHidden)
-                header.classList.remove(elClassBackground)
+                header.classList.remove(elClassHidden);
+                header.classList.remove(elClassBackground);
             } else if (this.wScrollDiff > 0 && header.classList.contains(elClassHidden)) {
                 // scrolled up; element slides in
-                header.classList.remove(elClassHidden)
-                header.classList.add(elClassBackground)
+                header.classList.remove(elClassHidden);
+                header.classList.add(elClassBackground);
             } else if (this.wScrollDiff < 0) {
                 // scrolled down
                 if (this.wScrollCurrent + this.wHeight >= this.dHeight && header.classList.contains(elClassHidden)) {
                     // scrolled to the very bottom; element slides in
-                    header.classList.remove(elClassHidden)
-                    header.classList.add(elClassBackground)
+                    header.classList.remove(elClassHidden);
+                    header.classList.add(elClassBackground);
                 } else {
                     // scrolled down; element slides out
-                    header.classList.add(elClassHidden)
+                    header.classList.add(elClassHidden);
                 }
             }
             this.wScrollBefore = this.wScrollCurrent;
@@ -60,8 +61,12 @@ export default class Header extends React.Component {
                 fn.apply(context, args);
             }
         };
-    };
+    }
     render() {
         return (<header ref={this.header}>{this.props.children}</header>);
     }
-}
\ No newline at end of file
+}
+
+Header.propTypes = {
+    children: PropTypes.node
+};