Example

This page contains a small example so you can have a glimpse of how to use and what is possible to do with the library.

Given the following feature written in Gherkin:

Feature: Login screen to authenticate users

	Scenario: Invalid username and password
	    Given I see an empty login form
	     When I introduce an invalid username
	      And I introduce an invalid password
	      And I press the login button
	     Then I see an error message saying 'Invalid credentials'

First, create a class that extends from GreenCoffeeTest and declare the Activity, the feature and the step definitions that will be used:

@RunWith(Parameterized.class)
public class LoginFeatureTest extends GreenCoffeeTest
{
    @Rule
    public ActivityTestRule<LoginActivity> activity = new ActivityTestRule<>(LoginActivity.class);

    public LoginFeatureTest(ScenarioConfig scenarioConfig)
    {
        super(scenarioConfig);
    }

    @Parameters(name = "{0}")
    public static Iterable<ScenarioConfig> scenarios() throws IOException
    {
        return new GreenCoffeeConfig(true) // automatically take a screenshot if a test fails
                        .withFeatureFromAssets("assets/login.feature")
                        .scenarios(
                            new Locale("en", "GB"),
                            new Locale("es", "ES")
                        ); // the locales used to run the scenarios (optional)
    }

    @Test
    public void test()
    {
        start(new LoginSteps());
    }
}

If no locales are defined, the default one will be used.

Next, create a class containing the steps definitions:

public class LoginSteps extends GreenCoffeeSteps
{
    @Given("^I see an empty login form$")
    public void iSeeAnEmptyLoginForm()
    {
        onViewWithId(R.id.login_input_username).isEmpty();
        onViewWithId(R.id.login_input_password).isEmpty();
    }

    @When("^I introduce an invalid username$")
    public void iIntroduceAnInvalidUsername()
    {
        onViewWithId(R.id.login_input_username).type("guest");
    }

    @When("^I introduce an invalid password$")
    public void iIntroduceAnInvalidPassword()
    {
        onViewWithId(R.id.login_input_password).type("1234");
    }

    @When("^I press the login button$")
    public void iPressTheLoginButton()
    {
        onViewWithId(R.id.login_button_doLogin).click();
    }

    @Then("^I see an error message saying 'Invalid credentials'$")
    public void iSeeAnErrorMessageSayingInvalidCredentials()
    {
        onViewWithText(R.string.login_credentials_error).isDisplayed();
    }
}

And that's it, now you can create your own tests using Green Coffee. This is how it looks when you run a more complex test:

You can see an example applied to a full app here.

Next chapter: Installation