Document complicated snapshot request testing logic

Author: Alec Gibson

test/client/snapshot-request.js

@@ -214,6 +214,15 @@ describe('SnapshotRequest', function () {
     it('can drop its connection and reconnect, and the callback is just called once', function (done) {
       var connection = backend.connect();
 
+      // Here we hook into middleware to make sure that we get the following flow:
+      // - Connection established
+      // - Connection attempts to fetch a snapshot
+      // - Snapshot is about to be returned
+      // - Connection is dropped before the snapshot is returned
+      // - Connection is re-established
+      // - Connection re-requests the snapshot
+      // - This time the fetch operation is allowed to complete (because of the connectionInterrupted flag)
+      // - The done callback is called just once (if it's called twice, then mocha will complain)
       var connectionInterrupted = false;
       backend.use(backend.MIDDLEWARE_ACTIONS.readSnapshots, function (request, callback) {
         if (!connectionInterrupted) {
@@ -231,6 +240,13 @@ describe('SnapshotRequest', function () {
     it('cannot send the same request twice over a connection', function (done) {
       var connection = backend.connect();
 
+      // Here we hook into the middleware to make sure that we get the following flow:
+      // - Attempt to fetch a snapshot
+      // - The snapshot request is temporarily stored on the Connection
+      // - Snapshot is about to be returned (ie the request was already successfully sent)
+      // - We attempt to resend the request again
+      // - The done callback is call just once, because the second request does not get sent
+      //   (if the done callback is called twice, then mocha will complain)
       var hasResent = false;
       backend.use(backend.MIDDLEWARE_ACTIONS.readSnapshots, function (request, callback) {
         if (!hasResent) {