3 files changed, 56 insertions, 24 deletions
diff --git a/devtools/client/storage/test/browser_storage_overflow.js b/devtools/client/storage/test/browser_storage_overflow.js
index 88181ca055..21b931c8e0 100644
--- a/devtools/client/storage/test/browser_storage_overflow.js
+++ b/devtools/client/storage/test/browser_storage_overflow.js
@@ -2,40 +2,58 @@
 // inspector table.
 "use strict";
 
+const ITEMS_PER_PAGE = 50;
+
 add_task(function* () {
   yield openTabAndSetupStorage(MAIN_DOMAIN + "storage-overflow.html");
 
-  let $ = id => gPanelWindow.document.querySelector(id);
-  let $$ = sel => gPanelWindow.document.querySelectorAll(sel);
-
   gUI.tree.expandAll();
   yield selectTreeItem(["localStorage", "http://test1.example.org"]);
+  checkCellLength(ITEMS_PER_PAGE);
+ 
+  yield scroll();
+  checkCellLength(ITEMS_PER_PAGE * 2);
 
-  let table = $("#storage-table .table-widget-body");
-  let cellHeight = $(".table-widget-cell").getBoundingClientRect().height;
+  yield scroll();
+  checkCellLength(ITEMS_PER_PAGE * 3);
 
-  is($$("#value .table-widget-cell").length, 50,
-     "Table should initially display 50 items");
+  // Check that the columns are sorted in a human readable way (ascending).
+  checkCellValues("ASC");
 
-  let onStoresUpdate = gUI.once("store-objects-updated");
-  table.scrollTop += cellHeight * 50;
-  yield onStoresUpdate;
+  // Sort descending.
+  clickColumnHeader("name");
 
-  is($$("#value .table-widget-cell").length, 100,
-     "Table should display 100 items after scrolling");
+  // Check that the columns are sorted in a human readable way (descending).
+  checkCellValues("DEC");
 
-  onStoresUpdate = gUI.once("store-objects-updated");
-  table.scrollTop += cellHeight * 50;
-  yield onStoresUpdate;
+  yield finishTests();
+});
 
-  is($$("#value .table-widget-cell").length, 150,
-     "Table should display 150 items after scrolling");
+function checkCellLength(len) {
+  let cells = gPanelWindow.document
+                          .querySelectorAll("#name .table-widget-cell");
+  let msg = `Table should initially display ${len} items`;
 
-  onStoresUpdate = gUI.once("store-objects-updated");
+  is(cells.length, len, msg);
+}
+
+function checkCellValues(order) {
+  let cells = [...gPanelWindow.document
+                              .querySelectorAll("#name .table-widget-cell")];
+  cells.forEach(function (cell, index, arr) {
+    let i = order === "ASC" ? index + 1 : arr.length - index;
+    is(cell.value, `item-${i}`, `Cell value is correct (${order}).`);
+  });
+}
+
+function* scroll() {
+  let $ = id => gPanelWindow.document.querySelector(id);
+
+  let table = $("#storage-table .table-widget-body");
+  let cell = $("#name .table-widget-cell");
+  let cellHeight = cell.getBoundingClientRect().height;
+
+  let onStoresUpdate = gUI.once("store-objects-updated");
   table.scrollTop += cellHeight * 50;
   yield onStoresUpdate;
-
-  is($$("#value .table-widget-cell").length, 160,
-     "Table should display all 160 items after scrolling");
-  yield finishTests();
-});
+}
diff --git a/devtools/client/storage/test/head.js b/devtools/client/storage/test/head.js
index ec6459b8dc..181132a450 100644
--- a/devtools/client/storage/test/head.js
+++ b/devtools/client/storage/test/head.js
@@ -734,6 +734,20 @@ function showColumn(id, state) {
 }
 
 /**
+ * Toggle sort direction on a column by clicking on the column header.
+ *
+ * @param  {String} id
+ *         The uniqueId of the given column.
+ */
+function clickColumnHeader(id) {
+  let columns = gUI.table.columns;
+  let column = columns.get(id);
+  let header = column.header;
+
+  header.click();
+}
+
+/**
  * Show or hide all columns.
  *
  * @param  {Boolean} state
diff --git a/devtools/client/storage/test/storage-overflow.html b/devtools/client/storage/test/storage-overflow.html
index ee8db36e63..6309046b38 100644
--- a/devtools/client/storage/test/storage-overflow.html
+++ b/devtools/client/storage/test/storage-overflow.html
@@ -11,7 +11,7 @@ Bug 1171903 - Storage Inspector endless scrolling
 <script type="text/javascript;version=1.8">
 "use strict";
 
-for (let i = 0; i < 160; i++) {
+for (let i = 1; i < 151; i++) {
   localStorage.setItem(`item-${i}`, `value-${i}`);
 }
 </script>