diff -r 000000000000 -r 6474c204b198 browser/devtools/scratchpad/test/browser_scratchpad_contexts.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/scratchpad/test/browser_scratchpad_contexts.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,155 @@
+/* vim: set ts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function test()
+{
+  waitForExplicitFinish();
+
+  gBrowser.selectedTab = gBrowser.addTab();
+  gBrowser.selectedBrowser.addEventListener("load", function onLoad() {
+    gBrowser.selectedBrowser.removeEventListener("load", onLoad, true);
+    openScratchpad(runTests);
+  }, true);
+
+  content.location = "data:text/html,test context switch in Scratchpad";
+}
+
+
+function runTests()
+{
+  let sp = gScratchpadWindow.Scratchpad;
+  let contentMenu = gScratchpadWindow.document.getElementById("sp-menu-content");
+  let chromeMenu = gScratchpadWindow.document.getElementById("sp-menu-browser");
+  let notificationBox = sp.notificationBox;
+
+  ok(contentMenu, "found #sp-menu-content");
+  ok(chromeMenu, "found #sp-menu-browser");
+  ok(notificationBox, "found Scratchpad.notificationBox");
+
+  let tests = [{
+    method: "run",
+    prepare: function() {
+      sp.setContentContext();
+
+      is(sp.executionContext, gScratchpadWindow.SCRATCHPAD_CONTEXT_CONTENT,
+         "executionContext is content");
+
+      is(contentMenu.getAttribute("checked"), "true",
+         "content menuitem is checked");
+
+      isnot(chromeMenu.getAttribute("checked"), "true",
+         "chrome menuitem is not checked");
+
+      ok(!notificationBox.currentNotification,
+         "there is no notification in content context");
+
+      sp.editor.setText("window.foobarBug636725 = 'aloha';");
+
+      ok(!content.wrappedJSObject.foobarBug636725,
+         "no content.foobarBug636725");
+    },
+    then: function() {
+      is(content.wrappedJSObject.foobarBug636725, "aloha",
+         "content.foobarBug636725 has been set");
+    }
+  },
+  {
+    method: "run",
+    prepare: function() {
+      sp.setBrowserContext();
+
+      is(sp.executionContext, gScratchpadWindow.SCRATCHPAD_CONTEXT_BROWSER,
+         "executionContext is chrome");
+
+      is(chromeMenu.getAttribute("checked"), "true",
+         "chrome menuitem is checked");
+
+      isnot(contentMenu.getAttribute("checked"), "true",
+         "content menuitem is not checked");
+
+      ok(notificationBox.currentNotification,
+         "there is a notification in browser context");
+
+      let [ from, to ] = sp.editor.getPosition(31, 32);
+      sp.editor.replaceText("2'", from, to);
+
+      is(sp.getText(), "window.foobarBug636725 = 'aloha2';",
+         "setText() worked");
+    },
+    then: function() {
+      is(window.foobarBug636725, "aloha2",
+         "window.foobarBug636725 has been set");
+
+      delete window.foobarBug636725;
+      ok(!window.foobarBug636725, "no window.foobarBug636725");
+    }
+  },
+  {
+    method: "run",
+    prepare: function() {
+      sp.editor.replaceText("gBrowser", sp.editor.getPosition(7));
+
+      is(sp.getText(), "window.gBrowser",
+         "setText() worked with no end for the replace range");
+    },
+    then: function([, , result]) {
+      is(result.class, "XULElement",
+         "chrome context has access to chrome objects");
+    }
+  },
+  {
+    method: "run",
+    prepare: function() {
+      // Check that the sandbox is cached.
+      sp.editor.setText("typeof foobarBug636725cache;");
+    },
+    then: function([, , result]) {
+      is(result, "undefined", "global variable does not exist");
+    }
+  },
+  {
+    method: "run",
+    prepare: function() {
+      sp.editor.setText("var foobarBug636725cache = 'foo';" +
+                 "typeof foobarBug636725cache;");
+    },
+    then: function([, , result]) {
+      is(result, "string",
+         "global variable exists across two different executions");
+    }
+  },
+  {
+    method: "run",
+    prepare: function() {
+      sp.editor.setText("var foobarBug636725cache2 = 'foo';" +
+                 "typeof foobarBug636725cache2;");
+    },
+    then: function([, , result]) {
+      is(result, "string",
+         "global variable exists across two different executions");
+    }
+  },
+  {
+    method: "run",
+    prepare: function() {
+      sp.setContentContext();
+
+      is(sp.executionContext, gScratchpadWindow.SCRATCHPAD_CONTEXT_CONTENT,
+         "executionContext is content");
+
+      sp.editor.setText("typeof foobarBug636725cache2;");
+    },
+    then: function([, , result]) {
+      is(result, "undefined",
+         "global variable no longer exists after changing the context");
+    }
+  }];
+
+  runAsyncCallbackTests(sp, tests).then(() => {
+    sp.setBrowserContext();
+    sp.editor.setText("delete foobarBug636725cache;" +
+               "delete foobarBug636725cache2;");
+    sp.run().then(finish);
+  });
+}
\ No newline at end of file