Burst

Burst is a unit testing library that uses enums to parameterize unit tests.

It is similar to TestParameterInjector in usage, but Burst is implemented as a Kotlin compiler plug-in. Burst supports all Kotlin platforms and works great in multiplatform projects.

Usage

Define an enum for the property you wish to vary.

enum class Soda {
  Pepsi, Coke
}

The enum can be simple as above, or contain data and methods specific to what you are testing.

enum class Collections {
  MutableSetOf {
    override fun <T> create(): MutableCollection<T> {
      return mutableSetOf()
    }
  },
  MutableListOf {
    override fun <T> create(): MutableCollection<T> {
      return mutableListOf()
    }
  },
  NewArrayDeque {
    override fun <T> create(): MutableCollection<T> {
      return ArrayDeque()
    }
  };

  abstract fun <T> create(): MutableCollection<T>?
}

Annotate your test class with @Burst, and accept an enum as a constructor parameter:

@Burst
class DrinkSodaTest(
  val soda: Soda = Soda.Pepsi,
) {
  ...
}

Burst will specialize the test class for each value in the enum. If you specified a default value for the parameter, it'll be used when you run the test in the IDE.

Burst can also specialize individual test functions:

@Test
fun drinkFavoriteSodas(soda: Soda = Soda.Pepsi) {
  ...
}

Use multiple enums for the combination of their variations.

@Test
fun collectSodas(
  soda: Soda = Soda.Pepsi,
  collectionsFactory: CollectionFactory = CollectionFactory.MutableSetOf,
) {
  ...
}

The test will be specialized for each combination of arguments.

• collectSodas(Soda.Pepsi, CollectionFactory.MutableSetOf)
• collectSodas(Soda.Pepsi, CollectionFactory.MutableListOf)
• collectSodas(Soda.Pepsi, CollectionFactory.NewArrayDeque)
• collectSodas(Soda.Coke, CollectionFactory.MutableSetOf)
• collectSodas(Soda.Coke, CollectionFactory.MutableListOf)
• collectSodas(Soda.Coke, CollectionFactory.NewArrayDeque)

Gradle Setup

Add Burst to your root project's buildscript dependencies:

buildscript {
  repositories {
    mavenCentral()
  }
  dependencies {
    classpath("app.cash.burst:burst-gradle-plugin:0.6.0")
  }
}

Then add the plugin to a module's build.gradle:

plugins {
  id("app.cash.burst")
  ...
}

License

Copyright (C) 2024 Cash App

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.