1 files changed, 42 insertions, 0 deletions
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_background_canvas.html b/toolkit/components/extensions/test/mochitest/test_ext_background_canvas.html
new file mode 100644
index 0000000000..e7745f08c5
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_background_canvas.html
@@ -0,0 +1,42 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for background page canvas rendering</title>
+  <script src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(async function test_background_canvas() {
+  function background() {
+    try {
+      let canvas = document.createElement("canvas");
+
+      let context = canvas.getContext("2d");
+
+      // This ensures that we have a working PresShell, and can successfully
+      // calculate font metrics.
+      context.font = "8pt fixed";
+
+      browser.test.notifyPass("background-canvas");
+    } catch (e) {
+      browser.test.fail(`Error: ${e} :: ${e.stack}`);
+      browser.test.notifyFail("background-canvas");
+    }
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({ background });
+
+  await extension.startup();
+  await extension.awaitFinish("background-canvas");
+  await extension.unload();
+});
+</script>
+
+</body>
+</html>