https://github.com/GoogleCloudPlatform/nodejs-docs-samples/pull/16#di…

…scussion_r42409314

datastore/query.js

@@ -345,33 +345,52 @@ Query.prototype.testLimit = function(callback) {
 
 Query.prototype.testCursorPaging = function(callback) {
   var pageSize = 1;
+  var pageCursor = '';
 
   datastore.createQuery = this.datastore.createQuery;
 
   // [START cursor_paging]
+  // By default, gcloud-node will paginate through all of the results that match
+  // a query, push them into an array, then return them to your callback after
+  // they have all been retrieved. You must execute `.autoPaginate(false)` on
+  // your query to disable this behavior.
   var query = datastore.createQuery('Task')
-    // Pagination is enabled by default in gcloud-node. To switch it off:
     .autoPaginate(false)
-    .limit(pageSize);
+    .limit(pageSize)
+    .start(pageCursor);
 
-  function onQueryResults(err, results, nextQuery) {
+  datastore.runQuery(query, function(err, results, nextQuery) {
     if (err) {
       // An error occurred while running the query.
       return;
     }
 
-    // If there are more results to retrieve, the cursor will have automatically
-    // been set on `nextQuery`.
+    var nextPageCursor;
+
     if (nextQuery) {
-      datastore.runQuery(nextQuery, onQueryResults);
+      // If there are more results to retrieve, the start cursor is
+      // automatically set on `nextQuery`. To get this value directly, access
+      // the `startVal` property.
+      nextPageCursor = nextQuery.startVal;
+    } else {
+      // No more results exist.
     }
-  }
-
-  datastore.runQuery(query, onQueryResults);
+  });
   // [END cursor_paging]
 
   delete datastore.createQuery;
-  this.datastore.runQuery(query, callback);
+  this.datastore.runQuery(query, function(err, results, nextQuery) {
+    if (err) {
+      callback(err);
+      return;
+    }
+
+    if (!nextQuery || !nextQuery.startVal) {
+      callback(new Error('A nextQuery with a startVal is not present.'));
+    } else {
+      callback();
+    }
+  });
 };
 
 Query.prototype.testEventualConsistentQuery = function(callback) {

test/datastore/testQuery.js

@@ -144,11 +144,7 @@ describe('limit query', function() {
 
 describe('cursor paging', function() {
   it('allows manual pagination through results', function(done) {
-    query.testCursorPaging(function(err, results, nextQuery) {
-      assert.ifError(err);
-      assert.notStrictEqual(nextQuery, null);
-      done();
-    });
+    query.testCursorPaging(done);
   });
 });