Conditional tests with Gradle
Kotest supports two ways to filter tests from the command line using Gradle. The first is the standard --tests flag that gradle supports, and the second is a kotest specific system property.
Gradle Test Filtering
When running Kotest via the JUnit Platform runner through gradle, Kotest supports the standard gradle syntax for test filtering. You can enable filtering either in the build script or via the --tests command-line option.
For example, in the build script:
//include all tests from package
Or via the command line:
gradle test --tests 'com.sksamuel.somepackage*'
gradle test --tests '*IntegrationTest'
See full Gradle documentation here.
Because gradle's test support is class.method based, we cannot filter tests down to the individual test level, only the class level.
Kotest Specific Test Filtering
To avoid the limitations with Gradle's
--tests support, Kotest offers its own flags which are provided via system properties or environment variables.
These flags support wildcards via
* and match either tests or specs:
|System property (JVM)||Environment variable (JVM or Native)||Scope|
|Spec (class) names|
System properties are only supported when targeting Kotlin/JVM. Environment variables are only supported when targeting Kotlin/JVM and Kotlin/Native.
This example would execute all tests in the com.somepackage (and nested) packages by setting the
kotest.filter.specs system property:
gradle test -Dkotest.filter.specs='com.somepackage.*'
This example would do the same, but uses the environment variable and so works for both Kotlin/JVM and Kotlin/Native:
kotest_filter_specs='com.somepackage.*' gradle test
Regardless of whether you use a system property or an environment variable, it's best to enclose the value in single quotes
rather than double quotes to avoid your shell performing globbing on any
This example would execute only tests that contain
Foo in the com.somepackage (and nested) packages:
gradle test -Dkotest.filter.specs='com.somepackage.*' -Dkotest.filter.tests='*Foo*'
This example would execute only tests that start with
Foo in any package:
gradle test -Dkotest.filter.tests='Foo*'