Espresso

• Used to write android UI Tests.
• Example of an Espresso test:

  @Test
  public void greeterSaysHello() {
    onView(withId(R.id.name_field)).perform(typeText("Steve"));
    onView(withId(R.id.greet_button)).perform(click());
    onView(withText("Hello Steve!")).check(matches(isDisplayed()));
  }
  

• Espresso tests state expectations, interactions, and assertions clearly without the distraction of boilerplate content.

Target audience

• it’s targeting developers who relay on automated testing.
• it can be used for black box testing.
• Espresso’s full power is unlocked by those who are familiar with the codebase under test, meaning those who implement this type of testing they know how to benefit from Espresso.

Synchronization capabilities

• onView() is always used to invoke testing.
• expresso won’t implement testing when 3 conditions occurs:
  • message queue is empty.
  • no instances of AsyncTask currently executing a task.
  • All developer-defined idling resources are idle.
• performing these checks, Espresso substantially increases the likelihood that only one UI action or assertion can occur at any given time. resource.

Packages

• espresso-core - Contains core and basic View matchers, actions, and assertions. See Basics and Recipes.
• espresso-web - Contains resources for WebView support.
• espresso-idling-resource - Espresso’s mechanism for synchronization with background jobs.
• espresso-contrib - External contributions that contain DatePicker, RecyclerView and Drawer actions, accessibility checks, and CountingIdlingResource.
• espresso-intents - Extension to validate and stub intents for hermetic testing.

• espresso-remote - Location of Espresso’s multi-process functionality.

• Note to rememeber: the reason i copied paseted here is because it’s new topic and i might want to diec more into details resource

Create UI tests with Espresso Test Recorder

• allow me to write tests for my app without writing any test case.
• this is done by recording interactions and add assertions to that snapshot.
• Test Recorder takes the saved recording and generate UI test.
• Test Recorder writes tests based on the Espresso Testing framework.
• Encourages developer to create UI tests based on user actions.

  Turn off animations on your test device

• prevent unexpected results.

Record an Espresso test

• Espresso tests consist of two primary components
  • UI interactions (include):
    • tap and type actions that a person may use to interact with app.
  • assertions on View elements.
    • Assertions verify contents of visual elements on the screen.

Record UI interactions

• Recording a test with Espresso Test Recorder process:
  • Run > Record Espresso Test.
  • In the Select Deployment Target window.
    • choose the device on which you want to record the test.
    • click ok.
  • Espresso Test Recorder triggers a build of project.
    • App shoudl be installed and launched before Espresso Test Recorder allow me to interact with it.
    • Record Your Test window appears after the app launches.
    • now i can start interact with the app.
    • recorded interactions appear in main panel.

Add assertions to verify UI elements

• Assertions verify the existence or contents of a View element through three main types:
  • text, check if the content of selected element exist.
  • exists, check if element picked is on screen.
  • does not exist, check if element does not exist in current screen.
• add an assertion
  • Click Add Assertion, Screen Capture dialog appears.
  • layout of current screen a panel on the right of the Record Your Test, view element create asserion, use the first drop-down menu in the Edit assertion, (selected View object is highlighted in a red box).
  • Select the assertion, from drop-down.
  • click Save Assertion or Save Assertion to do another asserion.

Save a recording

1. Complete Recording(Pick a test class name for your test).
2. Espresso Test Recorder gives test a unique name within its package based on the name of the launched activity.
   1. not added the Espresso dependencies to app, a Missing Espresso dependencies.
3. file automatically opens after Espresso Test Recorder generates it.

   Run an Espresso test locally

4. Open app module folder and navigate to the test you want to run.
5. Right-click on the test and click Run ‘testName.’
6. n the Select Deployment Target window, choose the device on which you want to run the test.