AndroidUnitTests

An android calculator application that showcases the following:

• MVP, Dagger2, Retrofit2/OkHttp3
• Developer debug drawer to enable/disable LeakCanary
• Unit testing with Robolectric and Mockito
• Functional UI tests using Espresso and MockWebServer
• Code coverage with JaCoCo

Requirements

This project uses retrolambda for those sweet Java 8 lambda functions and method references. Thus, you will need to have Java 8 installed on your machine. Set the JAVA8_HOME environment variable, and you should be good to go!

Testing

Unit Tests

The application unit tests are located in src/tests, with **debug ** specific tests being located in src/testDebug. The unit tests check classes in isolation, and mock dependencies.

The unit tests are also all java, so no android emulator or device is needed in order to run the tests. Android dependencies are mocked with Mockito or Robolectric as needed.

The tests use a custom test runner to mock some dagger injected dependencies and configure Robolectric. (Ex. For activity tests, presenters are mocked. We're testing the view in these tests after all, not the underlying backend.)

The tests can be run using ./gradlew testDebugUnitTest or ./gradlew testReleaseUnitTest. Results are in app/build/reports/tests

Functional UI Tests

The application functional tests are located in src/androidTest. These tests simulate user input and verify that the behaviour of the application was as expected. Espresso is used in order to simulate the user input. MockWebServer allows for the tests to simulate network calls without calling real services, and control the returned result.

All functional tests need an emulator or device to run.

The tests use a custom test runner to configure the MockWebServer, mock AndroidDevMetrics, and gain access to methods to control the tests.

The tests also use a rule in order to disable animations for instrumented tests. The espresso gradle file gives only connected test debug application permission to alter animation settings.

The tests can be run using ./gradlew connectedDebugAndroidTest. Results are in app/build/reports/androidTests

Code Coverage

Jacoco is used in order to view the code coverage of unit tests and is configured at codeQuality/jacoco.gradle. Jacoco coverage reports can be view in app/build/reports/jacoco

The application has ./gradlew testDebugUnitTestCoverage for viewing the test coverage of only the unit tests, and ./gradlew fullTestDebugUnitTestCoverage for viewing the test coverage of both unit and functional tests.

Details of Implementation

Dev Drawer

The DevModule and DevSetingsComponent are used to provide the dev drawer and tools used by the dev drawer. The main source code knows little about the developer libraries, and only knows of abstractions whose implementations are provided by the debug and release source sets.

Calculator

The CalculatorActivity follows a MVP design pattern, and a CalculatorPresenter is injected into the activity. This allows the activity and presenter to be tested separately, and allows the application to follow SOLID principles.

CalculatorPresenter: Handles input passed from the UI, and notifies the activity to update with corresponding information. The presenter uses a Calculator and ExpressionConverter

Calculator: Responsible for taking a list of calculator inputs, and evaluating the list.

ExpressionConverter: Responsible for normalizing an expression string, and converting an expression string to a list of calculator inputs.

Sources

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Quality Matters: http://artemzin.com/blog/android-development-culture-the-document-qualitymatters/

Disabling animations in espresso tests: https://product.reverb.com/2015/06/06/disabling-animations-in-espresso-for-android-testing/