15 Testing 5.2.3

(Quick Reference) # 15 Testing Version: 5.2.3 ## Table of Contents # 15 Testing Automated testing is a key part of Grails. Hence, Grails provides many ways to making testing easier from low level unit testing to high level functional tests. This section details the different capabilities that Grails offers for testing. The first thing to be aware of is that all of the `create-*` and `generate-\*` commands create `unit` or `integration` tests automatically. For example if you run the create-controller command as follows:
    grails create-controller com.acme.app.simple
Grails will create a controller at `grails-app/controllers/com/acme/app/SimpleController.groovy`, and also a unit test at `src/test/groovy/com/acme/app/SimpleControllerSpec.groovy`. What Grails won’t do however is populate the logic inside the test! That is left up to you.
| The default class name suffix is `Tests` but as of Grails 1.2.2, the suffix of `Test` is also supported.
#### Running Tests Tests are run with the test-app command:
    grails test-app
The command will produce output such as:
    -------------------------------------------------------
    Running Unit Tests...
    Running test FooTests...FAILURE
    Unit Tests Completed in 464ms ...
    -------------------------------------------------------

    Tests failed: 0 errors, 1 failures
whilst showing the reason for each test failure.
| You can force a clean before running tests by passing `-clean` to the `test-app` command.
Grails writes HTML test reports to the `build/reports/tests` directory and JUnit XML test reports to the `build/test-results` directory. The HTML reports are generally the best ones to look at. Using Grails' interactive mode confers some distinct advantages when executing tests. First, the tests will execute significantly faster on the second and subsequent runs. Second, a shortcut is available to open the HTML reports in your browser:
    open test-report
You can also run your unit tests from within most IDEs. #### Targeting Tests You can selectively target the test(s) to be run in different ways. To run all tests for a controller named `SimpleController` you would run:
    grails test-app SimpleController
This will run any tests for the class named `SimpleController`. Wildcards can be used…​
    grails test-app *Controller
This will test all classes ending in `Controller`. Package names can optionally be specified…​
    grails test-app some.org.*Controller
or to run all tests in a package…​
    grails test-app some.org.*
or to run all tests in a package including subpackages…​
    grails test-app some.org.**.*
You can also target particular test methods…​
    grails test-app SimpleController.testLogin
This will run the `testLogin` test in the `SimpleController` tests. You can specify as many patterns in combination as you like…​
    grails test-app some.org.* SimpleController.testLogin BookController
| In Grails 2.x, adding `-rerun` as an argument would only run those tests which failed in the previous test-app run. This argument is no longer supported.
| In Grails 3.x, you might need to specify the package name before the class name, as well as append "Spec" to the end. For example, if you want to run the test for the ProductController, you should use `grails test-app *.ProductControllerSpec`. Note that the star can be used if you don’t want to type the whole package hierarchy.
#### Debugging In order to debug your tests via a remote debugger, you can add `--debug-jvm` after `grails` in any commands, like so:
    grails --debug-jvm test-app
This will open the default Java remote debugging port, 5005, for you to attach a remote debugger from your editor / IDE of choice.
| This differs from Grails 2.3 and previous, where the `grails-debug` command existed.
#### Targeting Test Phases In addition to targeting certain tests, you can also target test phases. By default Grails has two testing phases `unit` and `integration.`
| Grails 2.x uses `phase:type` syntax. In Grails 3.0 it was removed, because it made no sense in Gradle context.
To execute `unit` tests you can run:
    grails test-app -unit
To run `integration` tests you would run…​
    grails test-app -integration
#### Targeting Tests When Using Phases Test and phase targeting can be applied at the same time:
    grails test-app some.org.**.* -unit
This would run all tests in the `unit` phase that are in the package `some.org` or a subpackage. ## 15.1 Unit Testing Unit testing are tests at the "unit" level. In other words you are testing individual methods or blocks of code without consideration for surrounding infrastructure. Unit tests are typically run without the presence of physical resources that involve I/O such as databases, socket connections or files. This is to ensure they run as quick as possible since quick feedback is important. Since Grails 3.3, the Grails Testing Support Framework is used for all unit tests. This support provides a set of traits. An example hello world test can be seen below:
    import spock.lang.Specification
    import grails.testing.web.controllers.ControllerUnitTest

    class HelloControllerTests extends Specification implements ControllerUnitTest<HelloController> {

        void "Test message action"() {
            when:"The message action is invoked"
            controller.message()

            then:"Hello is returned"
            response.text == 'Hello'
        }
    }
For more information on writing tests with Grails Testing Support see the dedicated documentation. Versions of Grails below 3.2 used the Grails Test Mixin Framework which was based on the `@TestMixin` AST transformation. This library has been superceded by the simpler and more IDE friendly trait based implementation. ## 15.2 Integration Testing Integration tests differ from unit tests in that you have full access to the Grails environment within the test. You can create an integration test using the create-integration-test command:
    $ grails create-integration-test Example
The above command will create a new integration test at the location `src/integration-test/groovy/<PACKAGE>/ExampleSpec.groovy`. Grails uses the test environment for integration tests and loads the application prior to the first test run. All tests use the same application state. #### Transactions Integration test methods run inside their own database transaction by default, which is rolled back at the end of each test method. This means that data saved during a test is not persisted to the database (which is shared across all tests). The default generated integration test template includes the Rollback annotation:
    import grails.testing.mixin.integration.Integration
    import grails.gorm.transactions.*
    import spock.lang.*

    @Integration
    @Rollback
    class ExampleSpec extends Specification {

        ...

        void "test something"() {
            expect:"fix me"
                true == false
        }
    }
The `Rollback` annotation ensures that each test method runs in a transaction that is rolled back. Generally this is desirable because you do not want your tests depending on order or application state. In Grails 3.0 tests rely on `grails.gorm.transactions.Rollback` annotation to bind the session in integration tests. Though each test method transaction is rolled back, the `setup()` method uses a separate transaction that is not rolled back. Data will persist to the database and will need to be cleaned up manually if `setup()` sets up data and persists them as shown in the below sample:
    import grails.testing.mixin.integration.Integration
    import grails.gorm.transactions.*
    import spock.lang.*

    @Integration
    @Rollback
    class BookSpec extends Specification {

        void setup() {
            // Below line would persist and not roll back
            new Book(name: 'Grails in Action').save(flush: true)
        }

        void "test something"() {
            expect:
            Book.count() == 1
        }
    }
To preload the database and automatically roll back setup logic, any persistence operations need to be called from the test method itself so that they can run within the test method’s rolled back transaction. Similar to usage of the `setupData()` method shown below which creates a record in database and after running other test will be rolled back:
    import grails.testing.mixin.integration.Integration
    import grails.gorm.transactions.*
    import spock.lang.*

    @Integration
    @Rollback
    class BookSpec extends Specification {

        void setupData() {
            // Below line would roll back
            new Book(name: 'Grails in Action').save(flush: true)
        }

        void "test something"() {
            given:
            setupData()

            expect:
            Book.count() == 1
        }
    }
#### Using Spring’s Rollback annotation Another transactional approach could be to use Spring’s @Rollback instead.
    import grails.testing.mixin.integration.Integration
    import org.springframework.test.annotation.Rollback
    import spock.lang.*

    @Integration
    @Rollback
    class BookSpec extends Specification {

        void setup() {
            new Book(name: 'Grails in Action').save(flush: true)
        }

        void "test something"() {
            expect:
            Book.count() == 1
        }
    }
| It isn’t possible to make `grails.gorm.transactions.Rollback` behave the same way as Spring’s Rollback annotation because `grails.gorm.transactions.Rollback` transforms the byte code of the class, eliminating the need for a proxy (which Spring’s version requires). This has the downside that you cannot implement it differently for different cases (as Spring does for testing).
#### DirtiesContext If you do have a series of tests that will share state you can remove the `Rollback` and the last test in the suite should feature the DirtiesContext annotation which will shutdown the environment and restart it fresh (note that this will have an impact on test run times). #### Autowiring To obtain a reference to a bean you can use the Autowired annotation. For example:
    ...
    import org.springframework.beans.factory.annotation.*

    @Integration
    @Rollback
    class ExampleServiceSpec extends Specification {

        @Autowired
        ExampleService exampleService
        ...

        void "Test example service"() {
            expect:
                exampleService.countExamples() == 0
        }
    }
#### Testing Controllers To integration test controllers it is recommended you use create-functional-test command to create a Geb functional test. See the following section on functional testing for more information. ## 15.3 Functional Testing Functional tests involve making HTTP requests against the running application and verifying the resultant behaviour. This is useful for end-to-end testing scenarios, such as making REST calls against a JSON API. Grails by default ships with support for writing functional tests using the Geb framework. To create a functional test you can use the `create-functional-test` command which will create a new functional test:
    $ grails create-functional-test MyFunctional
The above command will create a new Spock spec called `MyFunctionalSpec.groovy` in the `src/integration-test/groovy` directory. The test is annotated with the Integration annotation to indicate it is an integration test and extends the `GebSpec` super class:
    @Integration
    class HomeSpec extends GebSpec {

        def setup() {
        }

        def cleanup() {
        }

        void "Test the home page renders correctly"() {
            when:"The home page is visited"
                go '/'

            then:"The title is correct"
                $('title').text() == "Welcome to Grails"
        }
    }
When the test is run the application container will be loaded up in the background and you can send requests to the running application using the Geb API. Note that the application is only loaded once for the entire test run, so functional tests share the state of the application across the whole suite. In addition the application is loaded in the JVM as the test, this means that the test has full access to the application state and can interact directly with data services such as GORM to setup and cleanup test data. The `Integration` annotation supports an optional `applicationClass` attribute which may be used to specify the application class to use for the functional test. The class must extend GrailsAutoConfiguration.
    @Integration(applicationClass=com.demo.Application)
    class HomeSpec extends GebSpec {

        // ...

    }
If the `applicationClass` is not specified then the test runtime environment will attempt to locate the application class dynamically which can be problematic in multiproject builds where multiple application classes may be present. When running the server port by default will be randomly assigned. The `Integration` annotation adds a property of `serverPort` to the test class that you can use if you want to know what port the application is running on this isn’t needed if you are extending the `GebSpec` as shown above but can be useful information. If you want to run the tests on a fixed port (defined by the `server.port` configuration property), you need to manually annotate your test with `@SpringBootTest`:
    import grails.testing.mixin.integration.Integration
    import org.springframework.boot.test.context.SpringBootTest
    import spock.lang.Specification

    @Integration
    @SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.DEFINED_PORT)
    class MySpec extends Specification {

        // ...

    }
| Quick Reference (hide)