# Continuous Testing

Learn how to use continuous testing in your Quarkus Application.

## 1. Prerequisites

To complete this guide, you need:

- Roughly 15 minutes

- An IDE

- JDK 11+ installed with `JAVA_HOME` configured appropriately

- Apache Maven 3.9.3

- Optionally the Quarkus CLI if you want to use it

- Optionally Mandrel or GraalVM installed and configured appropriately if you want to build a native executable (or Docker if you use a native container build)

- The completed greeter application from the Getting Started Guide

## 2. Introduction

Quarkus supports continuous testing, where tests run immediately after code changes have been saved. This allows you to get instant feedback on your code changes. Quarkus detects which tests cover which code, and uses this information to only run the relevant tests when code is changed.

## 3. Solution

Start the Getting Started application (or any other application) using:

CLI

    quarkus dev

Maven

    ./mvnw quarkus:dev

Gradle

    ./gradlew --console=plain quarkusDev

Quarkus will start in development mode as normal, but down the bottom of the screen you should see the following:

    --
    Tests paused, press [r] to resume, [h] for more options>

Press `r` and the tests will start running. You should see the status change down the bottom of the screen as they are running, and it should finish with:

    --
    Tests all passed, 2 tests were run, 0 were skipped. Tests took 1470ms.
    Press [r] to re-run, [v] to view full results, [p] to pause, [h] for more options>

| If you want continuous testing to start automatically you can set `quarkus.test.continuous-testing=enabled` in `application.properties`. If you don’t want it at all you can change this to `disabled`.

Now you can start making changes to your application. Go into the `GreetingResource` and change the hello endpoint to return `"hello world"`, and save the file. Quarkus should immediately re-run the test, and you should get output similar to the following:

    2021-05-11 14:21:34,338 ERROR [io.qua.test] (Test runner thread) Test GreetingResourceTest#testHelloEndpoint() failed
    : java.lang.AssertionError: 1 expectation failed.
    Response body doesn't match expectation.
    Expected: is "hello"
      Actual: hello world

            at io.restassured.internal.ValidatableResponseImpl.body(ValidatableResponseImpl.groovy)
            at org.acme.getting.started.GreetingResourceTest.testHelloEndpoint(GreetingResourceTest.java:21)

    --
    Test run failed, 2 tests were run, 1 failed, 0 were skipped. Tests took 295ms
    Press [r] to re-run, [v] to view full results, [p] to pause, [h] for more options>

Change it back and the tests will run again.

## 4. Controlling Continuous Testing

There are various hotkeys you can use to control continuous testing. Pressing `h` will display the following list of commands:

    The following commands are available:
    [r] - Re-run all tests
    [f] - Re-run failed tests
    [b] - Toggle 'broken only' mode, where only failing tests are run (disabled)
    [v] - Print failures from the last test run
    [p] - Pause tests
    [o] - Toggle test output (disabled)
    [i] - Toggle instrumentation based reload (disabled)
    [l] - Toggle live reload (enabled)
    [s] - Force restart
    [h] - Display this help
    [q] - Quit

These are explained below:

[r] - Re-run all tests

  This will re-run every test

[f] - Re-run failed tests

  This will re-run every failing test

[b] - Toggle 'broken only' mode, where only failing tests are run

  Broken only mode will only run tests that have previously failed, even if other tests would normally be affected by a code change. This can be useful if you are modifying code that is used by lots of tests, but you only want to focus on debugging the failing one.

[v] - Print failures from the last test run

  Prints the failures to the console again, this can be useful if there has been lots of console output since the last run.

[p] - Pause tests

  Temporarily stops running tests. This can be useful if you are making lots of changes, and don’t want feedback until they are all done.

[o] - Toggle test output

  By default test output is filtered and not displayed on the console, so that test output and dev mode output is not interleaved. Enabling test output will print output to the console when tests are run. Even when output is disabled the filtered output is saved and can be viewed in the Dev UI.

[i] - Toggle instrumentation based reload

  This is not directly related to testing, but allows you to toggle instrumentation based reload. This will allow live reload to avoid a restart if a change does not affect the structure of a class, which gives a faster reload and allows you to keep state.

[l] - Toggle live reload

  This is not directly related to testing, but allows you to turn live reload on and off.

[s] - Force restart

  This will force a scan for changed files, and will perform a live reload with and changes. Note that even if there are no changes the application will still restart. This will still work even if live reload is disabled.

## 5. Continuous Testing Without Dev Mode

It is possible to run continuous testing without starting dev mode. This can be useful if dev mode will interfere with your tests (e.g. running wiremock on the same port), or if you only want to develop using tests. To start continuous testing mode run `mvn quarkus:test`.

| The Dev UI is not available when running in continuous testing mode, as this is provided by dev mode.

## 6. Multi-module Projects

Note that continuous testing supports multi-module projects, so tests in modules other than the application can still be run when files are changed. The modules that are run can be controlled using config as listed below.

This is enabled by default, and can be disabled via `quarkus.test.only-test-application-module=true`.

## 7. Configuring Continuous Testing

Continuous testing supports multiple configuration options that can be used to limit the tests that are run, and to control the output. The configuration properties are shown below:

Configuration property fixed at build time - All other configuration properties are overridable at runtime

Configuration property | Type | Default
--- | --- | ---
`quarkus.test.continuous-testing` If continuous testing is enabled. The default value is 'paused', which will allow you to start testing from the console or the Dev UI, but will not run tests on startup. If this is set to 'enabled' then testing will start as soon as the application has started. If this is 'disabled' then continuous testing is not enabled, and can’t be enabled without restarting the application. Environment variable: `QUARKUS_TEST_CONTINUOUS_TESTING` | `paused`, `enabled`, `disabled` | `paused`
`quarkus.test.display-test-output` If output from the running tests should be displayed in the console. Environment variable: `QUARKUS_TEST_DISPLAY_TEST_OUTPUT` | boolean | `false`
`quarkus.test.include-tags` Tags that should be included for continuous testing. This supports JUnit Tag Expressions. Environment variable: `QUARKUS_TEST_INCLUDE_TAGS` | list of string |
`quarkus.test.exclude-tags` Tags that should be excluded by default with continuous testing. This is ignored if include-tags has been set. Defaults to 'slow'. This supports JUnit Tag Expressions. Environment variable: `QUARKUS_TEST_EXCLUDE_TAGS` | list of string | `slow`
`quarkus.test.include-pattern` Tests that should be included for continuous testing. This is a regular expression and is matched against the test class name (not the file name). Environment variable: `QUARKUS_TEST_INCLUDE_PATTERN` | string |
`quarkus.test.exclude-pattern` Tests that should be excluded with continuous testing. This is a regular expression and is matched against the test class name (not the file name). This is ignored if include-pattern has been set. Environment variable: `QUARKUS_TEST_EXCLUDE_PATTERN` | string | `.*\.IT[^.]+|.*IT|.*ITCase`
`quarkus.test.include-engines` Test engine ids that should be included for continuous testing. Environment variable: `QUARKUS_TEST_INCLUDE_ENGINES` | list of string |
`quarkus.test.exclude-engines` Test engine ids that should be excluded by default with continuous testing. This is ignored if include-engines has been set. Environment variable: `QUARKUS_TEST_EXCLUDE_ENGINES` | list of string |
`quarkus.test.flat-class-path` Changes tests to use the 'flat' ClassPath used in Quarkus 1.x versions. This means all Quarkus and test classes are loaded in the same ClassLoader, however it means you cannot use continuous testing. Note that if you find this necessary for your application then you may also have problems running in development mode, which cannot use a flat class path. Environment variable: `QUARKUS_TEST_FLAT_CLASS_PATH` | boolean | `false`
`quarkus.test.native-image-profile` The profile to use when testing the native image Environment variable: `QUARKUS_TEST_NATIVE_IMAGE_PROFILE` | string | `prod`
`quarkus.test.integration-test-profile` The profile to use when testing using `@QuarkusIntegrationTest` Environment variable: `QUARKUS_TEST_INTEGRATION_TEST_PROFILE` | string | `prod`
`quarkus.test.profile` The profile (dev, test or prod) to use when testing using @QuarkusTest Environment variable: `QUARKUS_TEST_PROFILE` | string | `test`
`quarkus.test.profile.tags` The tags this profile is associated with. When the `quarkus.test.profile.tags` System property is set (its value is a comma separated list of strings) then Quarkus will only execute tests that are annotated with a `@TestProfile` that has at least one of the supplied (via the aforementioned system property) tags. Environment variable: `QUARKUS_TEST_PROFILE_TAGS` | list of string |
`quarkus.test.container.network` Controls the container network to be used when @QuarkusIntegration needs to launch the application in a container. This setting only applies if Quarkus does not need to use a shared network - which is the case if DevServices are used when running the test. Environment variable: `QUARKUS_TEST_CONTAINER_NETWORK` | string |
`quarkus.test.arg-line` Additional launch parameters to be used when Quarkus launches the produced artifact for `@QuarkusIntegrationTest` When the artifact is a `jar`, this string is passed right after the `java` command. When the artifact is a `container`, this string is passed right after the `docker run` command. When the artifact is a `native binary`, this string is passed right after the native binary name. Environment variable: `QUARKUS_TEST_ARG_LINE` | list of string |
`quarkus.test.wait-time` Used in `@QuarkusIntegrationTest` to determine how long the test will wait for the application to launch Environment variable: `QUARKUS_TEST_WAIT_TIME` | Duration | `PT1M`
`quarkus.test.hang-detection-timeout` Configures the hang detection in @QuarkusTest. If no activity happens (i.e. no test callbacks are called) over this period then QuarkusTest will dump all threads stack traces, to help diagnose a potential hang. Note that the initial timeout (before Quarkus has started) will only apply if provided by a system property, as it is not possible to read all config sources until Quarkus has booted. Environment variable: `QUARKUS_TEST_HANG_DETECTION_TIMEOUT` | Duration | `10M`
`quarkus.test.type` The type of test to run, this can be either: quarkus-test: Only runs `@QuarkusTest` annotated test classes unit: Only runs classes that are not annotated with `@QuarkusTest` all: Runs both, running the unit tests first Environment variable: `QUARKUS_TEST_TYPE` | `unit`, `quarkus-test`, `all` | `all`
`quarkus.test.class-clone-pattern` If a class matches this pattern then it will be cloned into the Quarkus ClassLoader even if it is in a parent first artifact. This is important for collections which can contain objects from the Quarkus ClassLoader, but for most parent first classes it will just cause problems. Environment variable: `QUARKUS_TEST_CLASS_CLONE_PATTERN` | string | `java\..*`
`quarkus.test.only-test-application-module` If this is true then only the tests from the main application module will be run (i.e. the module that is currently running mvn quarkus:dev). If this is false then tests from all dependency modules will be run as well. Environment variable: `QUARKUS_TEST_ONLY_TEST_APPLICATION_MODULE` | boolean | `false`
`quarkus.test.include-module-pattern` Modules that should be included for continuous testing. This is a regular expression and is matched against the module groupId:artifactId. Environment variable: `QUARKUS_TEST_INCLUDE_MODULE_PATTERN` | string |
`quarkus.test.exclude-module-pattern` Modules that should be excluded for continuous testing. This is a regular expression and is matched against the module groupId:artifactId. This is ignored if include-module-pattern has been set. Environment variable: `QUARKUS_TEST_EXCLUDE_MODULE_PATTERN` | string |
`quarkus.test.enable-callbacks-for-integration-tests` If the test callbacks should be invoked for the integration tests (tests annotated with `@QuarkusIntegrationTest`). Environment variable: `QUARKUS_TEST_ENABLE_CALLBACKS_FOR_INTEGRATION_TESTS` | boolean | `false`
`quarkus.test.container.additional-exposed-ports` Set additional ports to be exposed when @QuarkusIntegration needs to launch the application in a container. Environment variable: `QUARKUS_TEST_CONTAINER_ADDITIONAL_EXPOSED_PORTS` | `Map<String,String>` |
`quarkus.test.container.labels` A set of labels to add to the launched container Environment variable: `QUARKUS_TEST_CONTAINER_LABELS` | `Map<String,String>` |
`quarkus.test.env` Additional environment variables to be set in the process that `@QuarkusIntegrationTest` launches. Environment variable: `QUARKUS_TEST_ENV` | `Map<String,String>` |

| About the Duration format The format for durations uses the standard `java.time.Duration` format. You can learn more about it in the Duration#parse() javadoc. You can also provide duration values starting with a number. In this case, if the value consists only of a number, the converter treats the value as seconds. Otherwise, `PT` is implicitly prepended to the value to obtain a standard `java.time.Duration` format.