1 files changed, 28 insertions, 0 deletions
diff --git a/devtools/client/responsive/test/xpcshell/test_add_device_type.js b/devtools/client/responsive/test/xpcshell/test_add_device_type.js
new file mode 100644
index 0000000000..e824574380
--- /dev/null
+++ b/devtools/client/responsive/test/xpcshell/test_add_device_type.js
@@ -0,0 +1,28 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test adding a new device type.
+
+const {
+  addDeviceType,
+} = require("resource://devtools/client/responsive/actions/devices.js");
+
+add_task(async function () {
+  const store = Store();
+  const { getState, dispatch } = store;
+
+  dispatch(addDeviceType("phones"));
+
+  equal(getState().devices.types.length, 1, "Correct number of device types");
+  equal(
+    getState().devices.phones.length,
+    0,
+    "Defaults to an empty array of phones"
+  );
+  ok(
+    getState().devices.types.includes("phones"),
+    "Device types contain phones"
+  );
+});