1 files changed, 55 insertions, 0 deletions
diff --git a/devtools/client/inspector/fonts/test/browser_fontinspector_theme-change.js b/devtools/client/inspector/fonts/test/browser_fontinspector_theme-change.js
new file mode 100644
index 000000000..7fcfc9cc2
--- /dev/null
+++ b/devtools/client/inspector/fonts/test/browser_fontinspector_theme-change.js
@@ -0,0 +1,55 @@
+/* vim: set ts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+requestLongerTimeout(2);
+
+// Test that the preview images are updated when the theme changes.
+
+const { getTheme, setTheme } = require("devtools/client/shared/theme");
+
+const TEST_URI = URL_ROOT + "browser_fontinspector.html";
+const originalTheme = getTheme();
+
+registerCleanupFunction(() => {
+  info(`Restoring theme to '${originalTheme}.`);
+  setTheme(originalTheme);
+});
+
+add_task(function* () {
+  let { inspector, view } = yield openFontInspectorForURL(TEST_URI);
+  let { chromeDoc: doc } = view;
+
+  yield selectNode(".normal-text", inspector);
+
+  // Store the original preview URI for later comparison.
+  let originalURI = doc.querySelector("#all-fonts .font-preview").src;
+  let newTheme = originalTheme === "light" ? "dark" : "light";
+
+  info(`Original theme was '${originalTheme}'.`);
+
+  yield setThemeAndWaitForUpdate(newTheme, inspector);
+  isnot(doc.querySelector("#all-fonts .font-preview").src, originalURI,
+    "The preview image changed with the theme.");
+
+  yield setThemeAndWaitForUpdate(originalTheme, inspector);
+  is(doc.querySelector("#all-fonts .font-preview").src, originalURI,
+    "The preview image is correct after the original theme was restored.");
+});
+
+/**
+ * Sets the current theme and waits for fontinspector-updated event.
+ *
+ * @param {String} theme - the new theme
+ * @param {Object} inspector - the inspector panel
+ */
+function* setThemeAndWaitForUpdate(theme, inspector) {
+  let onUpdated = inspector.once("fontinspector-updated");
+
+  info(`Setting theme to '${theme}'.`);
+  setTheme(theme);
+
+  info("Waiting for font-inspector to update.");
+  yield onUpdated;
+}