1 files changed, 55 insertions, 0 deletions
diff --git a/testing/web-platform/tests/webusb/usbInterface.https.any.js b/testing/web-platform/tests/webusb/usbInterface.https.any.js
new file mode 100644
index 0000000000..22692a7d94
--- /dev/null
+++ b/testing/web-platform/tests/webusb/usbInterface.https.any.js
@@ -0,0 +1,55 @@
+// META: script=/resources/test-only-api.js
+// META: script=/webusb/resources/fake-devices.js
+// META: script=/webusb/resources/usb-helpers.js
+'use strict';
+
+usb_test(async () => {
+  let { device } =  await getFakeDevice();
+  let configuration = new USBConfiguration(
+      device, device.configurations[1].configurationValue);
+  let usbInterface = new USBInterface(
+      configuration, configuration.interfaces[0].interfaceNumber);
+  assertDeviceInfoEquals(
+      usbInterface, fakeDeviceInit.configurations[1].interfaces[0]);
+}, 'Can construct a USBInterface.');
+
+usb_test(async () => {
+  let { device } =  await getFakeDevice();
+  let configuration = new USBConfiguration(
+      device, device.configurations[1].configurationValue);
+  try {
+    let usbInterface = new USBInterface(
+        configuration, configuration.interfaces.length);
+    assert_unreached('USBInterface should reject an invalid interface number');
+  } catch (error) {
+    assert_equals(error.name, 'RangeError');
+  }
+}, 'Constructing a USBInterface with an invalid interface number ' +
+    'throws a range error.');
+
+usb_test(async () => {
+  let { device } =  await getFakeDevice();
+  await device.open();
+  await device.selectConfiguration(2);
+  let configuration = new USBConfiguration(
+      device, device.configurations[1].configurationValue);
+  let usbInterface = new USBInterface(
+      configuration, configuration.interfaces[0].interfaceNumber);
+  assert_equals(usbInterface.alternate.alternateSetting, 0);
+}, 'The alternate attribute of USBInterface returns the one with ' +
+   'bAlternateSetting 0 if the interface has not been claimed.');
+
+usb_test(async () => {
+  let { device } =  await getFakeDevice();
+  await device.open();
+  await device.selectConfiguration(2);
+  await device.claimInterface(0);
+  let configuration = new USBConfiguration(
+    device, device.configurations[1].configurationValue);
+  let usbInterface = new USBInterface(
+    configuration, configuration.interfaces[0].interfaceNumber);
+  assert_equals(usbInterface.alternate.alternateSetting, 0);
+  await device.selectAlternateInterface(0, 1);
+  assert_equals(usbInterface.alternate.alternateSetting, 1);
+}, 'The alternate attribute of USBInterface returns the active alternate ' +
+   'interface.');