Partial merge of develop to experimental

Does not include #2336 as the file has been moved out from underneath it:
will do this separately

test/test-utils.js

@@ -310,19 +310,26 @@ export function wrapInMatrixClientContext(WrappedComponent) {
 /**
  * Call fn before calling componentDidUpdate on a react component instance, inst.
  * @param {React.Component} inst an instance of a React component.
+ * @param {integer} updates Number of updates to wait for. (Defaults to 1.)
  * @returns {Promise} promise that resolves when componentDidUpdate is called on
  *                    given component instance.
  */
-export function waitForUpdate(inst) {
+export function waitForUpdate(inst, updates = 1) {
     return new Promise((resolve, reject) => {
         const cdu = inst.componentDidUpdate;
 
+        console.log(`Waiting for ${updates} update(s)`);
+
         inst.componentDidUpdate = (prevProps, prevState, snapshot) => {
-            resolve();
+            updates--;
+            console.log(`Got update, ${updates} remaining`);
+
+            if (updates == 0) {
+                inst.componentDidUpdate = cdu;
+                resolve();
+            }
 
             if (cdu) cdu(prevProps, prevState, snapshot);
-
-            inst.componentDidUpdate = cdu;
         };
     });
 }