Burst is a library for parameterizing 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

Annotate your test class with @Burst.

Declare a parameter in your test's constructor that calls burstValues() as its default.

@Burst
class DrinkSodaTest(
  val soda: String = burstValues("Pepsi", "Coke"),
) {
  ...
}

Burst will specialize the test class for each argument to burstValues(). The first value is used when you run the test in the IDE.

Parameterize Functions

Burst can specialize individual test functions:

@Test
fun drinkSoda(
  soda: String = burstValues("Pepsi", "Coke"),
) {
  ...
}

Booleans and Enums

If your parameter is a boolean or an enum, you don't need to call burstValues(). Burst will test all values. Specify a default value to use that when you launch the test from the IDE.

@Burst
class DrinkSodaTest(
  val ice: Boolean = true,
) {
  ...
}

enum class Distribution {
  Fountain, Can, Bottle
}

@Burst
class DrinkSodaTest(
  val distribution: Distribution = Distribution.Can,
) {
  ...
}

If the parameter is nullable, Burst will also test with null.

Multiple Parameters

Use multiple parameters to test all variations.

@Test
fun drinkSoda(
  soda: String = burstValues("Pepsi", "Coke"),
  ice: Boolean,
  distribution: Distribution,
) {
  ...
}

The test will be specialized for each combination of arguments.

• drinkSoda("Pepsi", true, Distribution.Fountain)
• drinkSoda("Pepsi", true, Distribution.Can)
• drinkSoda("Pepsi", true, Distribution.Bottle)
• drinkSoda("Pepsi", false, Distribution.Fountain)
• drinkSoda("Pepsi", false, Distribution.Can)
• drinkSoda("Pepsi", false, Distribution.Bottle)
• drinkSoda("Coke", true, Distribution.Fountain)
• drinkSoda("Coke", true, Distribution.Can)
• drinkSoda("Coke", true, Distribution.Bottle)
• drinkSoda("Coke", false, Distribution.Fountain)
• drinkSoda("Coke", false, Distribution.Can)
• drinkSoda("Coke", false, Distribution.Bottle)

Gradle Setup

Add Burst to your root project's buildscript dependencies:

buildscript {
  repositories {
    mavenCentral()
  }
  dependencies {
    classpath("app.cash.burst:burst-gradle-plugin:2.0.0")
  }
}

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.