Support default arguments

CHANGELOG.md

@@ -3,6 +3,10 @@
 ## [Unreleased]
 [Unreleased]: https://github.com/cashapp/burst/compare/0.5.0...HEAD
 
+**Added**
+
+ * New: Use default parameter values to configure which specialization runs in the IDE.
+
 
 ## [0.5.0] *(2024-10-17)*
 [0.5.0]: https://github.com/cashapp/burst/releases/tag/0.4.0

README.md

@@ -47,19 +47,20 @@ Annotate your test class with `@Burst`, and accept an enum as a constructor para
 ```kotlin
 @Burst
 class DrinkSodaTest(
-  val soda: Soda,
+  val soda: Soda = Soda.Pepsi,
 ) {
   ...
 }
 ```
 
-Burst will specialize the test class for each value in the enum.
+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:
 
 ```kotlin
 @Test
-fun drinkFavoriteSodas(soda: Soda) {
+fun drinkFavoriteSodas(soda: Soda = Soda.Pepsi) {
   ...
 }
 ```
@@ -68,7 +69,10 @@ Use multiple enums for the combination of their variations.
 
 ```kotlin
 @Test
-fun collectSodas(soda: Soda, collectionsFactory: CollectionFactory) {
+fun collectSodas(
+  soda: Soda = Soda.Pepsi,
+  collectionsFactory: CollectionFactory = CollectionFactory.MutableSetOf,
+) {
   ...
 }
 ```

burst-gradle-plugin/src/test/kotlin/app/cash/burst/gradle/BurstGradlePluginTest.kt

@@ -17,13 +17,10 @@
 package app.cash.burst.gradle
 
 import assertk.assertThat
-import assertk.assertions.contains
 import assertk.assertions.containsExactlyInAnyOrder
-import assertk.assertions.isEmpty
 import assertk.assertions.isEqualTo
 import assertk.assertions.isFalse
 import assertk.assertions.isIn
-import assertk.assertions.isTrue
 import java.io.File
 import org.gradle.testkit.runner.GradleRunner
 import org.gradle.testkit.runner.TaskOutcome
@@ -70,59 +67,17 @@ class BurstGradlePluginTest {
 
     val testResults = projectDir.resolve("lib/build/test-results")
 
-    // The original test class runs the default specialization.
-    with(readTestSuite(testResults.resolve("$testTaskName/TEST-CoffeeTest.xml"))) {
-      assertThat(testCases.map { it.name }).containsExactlyInAnyOrder(
-        "test[$platformName]",
-        "test_Milk[$platformName]",
-        "test_None[$platformName]",
-        "test_Oat[$platformName]",
-      )
-
-      val defaultFunction = testCases.single { it.name == "test[$platformName]" }
-      assertThat(defaultFunction.skipped).isFalse()
-
-      val defaultSpecialization = testCases.single { it.name == "test_None[$platformName]" }
-      assertThat(defaultSpecialization.skipped).isTrue()
-
-      val sampleSpecialization = testCases.single { it.name == "test_Milk[$platformName]" }
-      assertThat(sampleSpecialization.skipped).isFalse()
-    }
-
-    // The default test class is completely skipped.
-    with(readTestSuite(testResults.resolve("$testTaskName/TEST-CoffeeTest_Decaf.xml"))) {
-      assertThat(testCases.map { it.name }).containsExactlyInAnyOrder(
-        "test[$platformName]",
-        "test_Milk[$platformName]",
-        "test_None[$platformName]",
-        "test_Oat[$platformName]",
-      )
+    // There's no default specialization.
+    assertThat(testResults.resolve("$testTaskName/TEST-CoffeeTest.xml").exists()).isFalse()
 
-      val defaultFunction = testCases.single { it.name == "test[$platformName]" }
-      assertThat(defaultFunction.skipped).isTrue()
-
-      val defaultSpecialization = testCases.single { it.name == "test_None[$platformName]" }
-      assertThat(defaultSpecialization.skipped).isTrue()
-
-      val sampleSpecialization = testCases.single { it.name == "test_Milk[$platformName]" }
-      assertThat(sampleSpecialization.skipped).isTrue()
-    }
-
-    // Another test class is executed normally with nothing skipped.
+    // Each test class is executed normally with nothing skipped.
     with(readTestSuite(testResults.resolve("$testTaskName/TEST-CoffeeTest_Regular.xml"))) {
       assertThat(testCases.map { it.name }).containsExactlyInAnyOrder(
-        "test[$platformName]",
         "test_Milk[$platformName]",
         "test_None[$platformName]",
         "test_Oat[$platformName]",
       )
 
-      val defaultFunction = testCases.single { it.name == "test[$platformName]" }
-      assertThat(defaultFunction.skipped).isFalse()
-
-      val defaultSpecialization = testCases.single { it.name == "test_None[$platformName]" }
-      assertThat(defaultSpecialization.skipped).isTrue()
-
       val sampleSpecialization = testCases.single { it.name == "test_Milk[$platformName]" }
       assertThat(sampleSpecialization.skipped).isFalse()
     }
@@ -142,7 +97,6 @@ class BurstGradlePluginTest {
     val testSuite = readTestSuite(testXmlFile)
 
     assertThat(testSuite.testCases.map { it.name }).containsExactlyInAnyOrder(
-      "test",
       "test_Decaf_Milk",
       "test_Decaf_None",
       "test_Decaf_Oat",
@@ -154,12 +108,6 @@ class BurstGradlePluginTest {
       "test_Regular_Oat",
     )
 
-    val originalTest = testSuite.testCases.single { it.name == "test" }
-    assertThat(originalTest.skipped).isFalse()
-
-    val defaultSpecialization = testSuite.testCases.single { it.name == "test_Decaf_None" }
-    assertThat(defaultSpecialization.skipped).isTrue()
-
     val sampleSpecialization = testSuite.testCases.single { it.name == "test_Regular_Milk" }
     assertThat(sampleSpecialization.skipped).isFalse()
   }
@@ -174,22 +122,8 @@ class BurstGradlePluginTest {
 
     val testResults = projectDir.resolve("lib/build/test-results")
 
-    val coffeeTest = readTestSuite(testResults.resolve("test/TEST-CoffeeTest.xml"))
-    val coffeeTestTest = coffeeTest.testCases.single()
-    assertThat(coffeeTestTest.name).isEqualTo("test")
-    assertThat(coffeeTest.systemOut).isEqualTo(
-      """
-      |set up Decaf None
-      |running Decaf None
-      |
-      """.trimMargin(),
-    )
-
-    val defaultTest = readTestSuite(testResults.resolve("test/TEST-CoffeeTest_Decaf_None.xml"))
-    val defaultTestTest = defaultTest.testCases.single()
-    assertThat(defaultTestTest.name).isEqualTo("test")
-    assertThat(defaultTestTest.skipped).isTrue()
-    assertThat(defaultTest.systemOut).isEmpty()
+    // There's no default specialization.
+    assertThat(testResults.resolve("test/TEST-CoffeeTest.xml").exists()).isFalse()
 
     val sampleTest = readTestSuite(testResults.resolve("test/TEST-CoffeeTest_Regular_Milk.xml"))
     val sampleTestTest = sampleTest.testCases.single()
@@ -215,6 +149,49 @@ class BurstGradlePluginTest {
     assertThat(result.task(androidTestTaskName)!!.outcome).isIn(*SUCCESS_OUTCOMES)
   }
 
+  @Test
+  fun defaultArguments() {
+    val projectDir = File("src/test/projects/defaultArguments")
+
+    val result = createRunner(projectDir, "clean", ":lib:test").build()
+    assertThat(result.task(":lib:test")!!.outcome).isIn(*SUCCESS_OUTCOMES)
+
+    val testResults = projectDir.resolve("lib/build/test-results")
+
+    // The original test class runs the default specialization.
+    with(readTestSuite(testResults.resolve("test/TEST-CoffeeTest.xml"))) {
+      assertThat(testCases.map { it.name }).containsExactlyInAnyOrder(
+        "test",
+        "test_None",
+        "test_Oat",
+      )
+
+      val defaultFunction = testCases.single { it.name == "test" }
+      assertThat(defaultFunction.skipped).isFalse()
+
+      val sampleSpecialization = testCases.single { it.name == "test_Oat" }
+      assertThat(sampleSpecialization.skipped).isFalse()
+    }
+
+    // No subclass is generated for the default specialization.
+    assertThat(testResults.resolve("test/TEST-CoffeeTest_Regular.xml").exists()).isFalse()
+
+    // Another test class is executed normally with nothing skipped.
+    with(readTestSuite(testResults.resolve("test/TEST-CoffeeTest_Double.xml"))) {
+      assertThat(testCases.map { it.name }).containsExactlyInAnyOrder(
+        "test",
+        "test_None",
+        "test_Oat",
+      )
+
+      val defaultFunction = testCases.single { it.name == "test" }
+      assertThat(defaultFunction.skipped).isFalse()
+
+      val sampleSpecialization = testCases.single { it.name == "test_Oat" }
+      assertThat(sampleSpecialization.skipped).isFalse()
+    }
+  }
+
   private fun createRunner(
     projectDir: File,
     vararg taskNames: String,

burst-gradle-plugin/src/test/projects/defaultArguments/build.gradle.kts

@@ -0,0 +1,37 @@
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+import org.jetbrains.kotlin.gradle.tasks.KotlinJvmCompile
+
+buildscript {
+  repositories {
+    maven {
+      url = file("$rootDir/../../../../../build/testMaven").toURI()
+    }
+    mavenCentral()
+    google()
+  }
+  dependencies {
+    classpath("app.cash.burst:burst-gradle-plugin:${project.property("burstVersion")}")
+    classpath(libs.kotlin.gradlePlugin)
+  }
+}
+
+allprojects {
+  repositories {
+    maven {
+      url = file("$rootDir/../../../../../build/testMaven").toURI()
+    }
+    mavenCentral()
+    google()
+  }
+
+  tasks.withType(JavaCompile::class.java).configureEach {
+    sourceCompatibility = "1.8"
+    targetCompatibility = "1.8"
+  }
+
+  tasks.withType(KotlinJvmCompile::class.java).configureEach {
+    compilerOptions {
+      jvmTarget.set(JvmTarget.JVM_1_8)
+    }
+  }
+}

burst-gradle-plugin/src/test/projects/defaultArguments/lib/build.gradle.kts

@@ -0,0 +1,8 @@
+plugins {
+  kotlin("jvm")
+  id("app.cash.burst")
+}
+
+dependencies {
+  testImplementation(kotlin("test"))
+}

burst-gradle-plugin/src/test/projects/defaultArguments/lib/src/test/kotlin/CoffeeTest.kt

@@ -0,0 +1,22 @@
+import app.cash.burst.Burst
+import kotlin.test.BeforeTest
+import kotlin.test.Test
+
+@Burst
+class CoffeeTest(
+  private val espresso: Espresso = Espresso.Regular,
+) {
+  @BeforeTest
+  fun setUp() {
+    println("set up $espresso")
+  }
+
+  @Test
+  fun test(dairy: Dairy = Dairy.Milk) {
+    println("running $espresso $dairy")
+  }
+}
+
+enum class Espresso { Decaf, Regular, Double }
+
+enum class Dairy { None, Milk, Oat }

burst-gradle-plugin/src/test/projects/defaultArguments/settings.gradle.kts

@@ -0,0 +1,9 @@
+dependencyResolutionManagement {
+  versionCatalogs {
+    create("libs") {
+      from(files("../../../../../gradle/libs.versions.toml"))
+    }
+  }
+}
+
+include(":lib")