1# SDK Sandbox UI Tests
2
3## Overview
4
5The SDK Sandbox UI test suite facilitates the testing of the UI components of the SDK sandbox, such
6as the rendering of remote views into a `SurfaceView`. This test suite enables the testing of UI
7functionality on multiple device specifications, which may be configured on a per-class basis.
8
9These tests make use of the `SdkSandboxUiTestRule` rule, which includes a screenshot
10asserter. This asserter may be used to compare portions of the emulated display with "golden"
11images from the `assets` directory. The screenshot asserter uses an `AlmostPerfectMatcher` to
12ensure that the rendered views are indistinguishable from the expected golden images (allowing a
13very small tolerance to allow for rendering differences on different devices).
14
15As part of the `SdkSandboxUiTestRule`, an SDK is loaded in the test app. The loaded SDK
16may be configured on a per-class basis, by passing the name of the `SandboxedSdkProvider` to the
17`SdkSandboxUiTestRule`. If the test needs to interact with the SDK's `SandboxedSdk` object, this
18can be done by calling the `getSandboxedSdk()` method of the test rule.
19
20## Rendering Remote Views
21Remote views may be loaded by using `SdkSandboxUiTestRule.renderInView()`. This will render a view
22of size `width` and `height` in pixels. The view will contain the drawable defined by the passed
23resource ID.
24
25## Interacting with Activities
26
27To test UI interactions such as clicking and scrolling, or to locate a view on screen, it will
28sometimes be necessary for the test to interact with the test activity. This can be done
29by calling `getActivityScenario()` on the test rule. The test app will be launched with the default
30activity class, which may be specified in the constructor of the test rule.
31The activity may be switched by calling `switchActivity(Activity activity)`.
32
33
34```java
35public class ExampleTest {
36    SdkSandboxUiRule mRule;
37
38    @Test
39    public void testActivities() {
40        // Default activity is current running
41        mRule.getActivityScenario().onActivity(activity -> {
42            // interact with activity
43        });
44        mRule.switchActivity(NewActivity.class);
45        // NewActivity is now running
46        mRule.getActivityScenario().onActivity(activity -> {
47            // interact with new activity
48        });
49    }
50}
51```
52
53## Input Injection
54Due to `SurfaceView` restrictions, `MotionEvents` cannot be programmatically injected into remotely
55rendered views. Instead, the input event can be simulated using the test instrumentation.
56For example, to simulate a click we can find the x and y co-ordinates of the view on screen, and
57send `MOTION_DOWN` and `MOTION_UP` events to the test instrumentation at these co-ordinates.
58