Continued porting to react, approaching beta

src/app/utils/UtilityFunctions.js

@@ -0,0 +1,49 @@
+
+/**
+ * Wraps the callback/context menu handler such that the default
+ * operation can proceed if the SHIFT key is held while right-clicked
+ * @param  {Function} cb Callback for contextMenu
+ * @return {Function}    Wrapped contextmenu handler
+ */
+export function wrapCtxMenu(cb) {
+  return (event) => {
+    if (!event.getModifierState('Shift')) {
+      event.preventDefault();
+      cb.call(null, event);
+    }
+  };
+}
+
+/**
+ * Compares A and B and return true using strict comparison (===)
+ * @param  {any} objA   A
+ * @param  {any} objB   B
+ * @return {boolean}    true if A === B OR A properties === B properties
+ */
+export function shallowEqual(objA, objB) {
+  if (objA === objB) {
+    return true;
+  }
+
+  if (typeof objA !== 'object' || objA === null ||
+      typeof objB !== 'object' || objB === null) {
+    return false;
+  }
+
+  let keysA = Object.keys(objA);
+  let keysB = Object.keys(objB);
+
+  if (keysA.length !== keysB.length) {
+    return false;
+  }
+
+  // Test for A's keys different from B.
+  let bHasOwnProperty = Object.prototype.hasOwnProperty.bind(objB);
+  for (let i = 0; i < keysA.length; i++) {
+    if (!bHasOwnProperty(keysA[i]) || objA[keysA[i]] !== objB[keysA[i]]) {
+      return false;
+    }
+  }
+
+  return true;
+}