Test: check existence of the start button (related to #34)

test/common.js

@@ -0,0 +1,17 @@
+/* See license.txt for terms of usage */
+
+"use strict";
+
+const { main } = require("../index.js");
+const { resolve } = require("sdk/core/promise");
+
+/**
+ * Load Pixel Perfect add-on.
+ */
+function loadPixelPerfect() {
+  main({loadReason: "install"});
+  return resolve();
+};
+
+// Exports from this module
+exports.loadPixelPerfect = loadPixelPerfect;

test/test-start-button.js

@@ -0,0 +1,21 @@
+/* See license.txt for terms of usage */
+
+"use strict";
+
+const { StartButton } = require("../lib/start-button.js");
+const { getMostRecentBrowserWindow } = require("sdk/window/utils");
+const { loadPixelPerfect } = require("./common.js");
+
+/**
+ * Check that the start button is available in Firefox toolbar.
+ */
+exports["test Start Button"] = function(assert, done) {
+  loadPixelPerfect().then(() => {
+    let browser = getMostRecentBrowserWindow();
+    let element = StartButton.getButton(browser.document);
+    assert.ok(element, "The start button must be available");
+    done();
+  });
+};
+
+require("sdk/test").run(exports);