test: migrate two suites to TestBalloon as a PoC

Wire the TestBalloon plugin into jindong-core and jindong-compose
alongside Kotest, and migrate exactly two suites to it:

- HapticIntensityTest: data-driven cases become one test per input via a
  plain Kotlin loop, so each input is named and fails independently
  (7 tests -> 14, same assertions).
- JindongApplierTest: the lateinit + beforeEach fixture is replaced by
  testFixture { Fixture() } asContextForEach, making isolation
  structural. Test bodies are unchanged apart from context -> testSuite.

Assertions stay on kotest-assertions-core in both; only the spec engine
changed. Every other suite is left on Kotest, which verifies the two
frameworks coexist in the same source set.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: 수현

gradle/libs.versions.toml

@@ -11,6 +11,7 @@ composeMultiplatform = "1.10.0"
 composeBom = "2025.12.01"
 coroutines = "1.10.2"
 kotest = "6.0.7"
+testballoon = "1.0.1-K2.3.0"
 ksp = "2.3.4"
 robolectric = "4.16"
 androidxTest = "1.7.0"
@@ -29,6 +30,7 @@ kotest-framework-engine = { module = "io.kotest:kotest-framework-engine", versio
 kotest-assertions-core = { module = "io.kotest:kotest-assertions-core", version.ref = "kotest" }
 kotest-property = { module = "io.kotest:kotest-property", version.ref = "kotest" }
 kotest-runner-junit5 = { module = "io.kotest:kotest-runner-junit5", version.ref = "kotest" }
+testballoon-framework-core = { module = "de.infix.testBalloon:testBalloon-framework-core", version.ref = "testballoon" }
 junit-vintage-engine = { module = "org.junit.vintage:junit-vintage-engine", version.ref = "junit5" }
 robolectric = { module = "org.robolectric:robolectric", version.ref = "robolectric" }
 androidx-test-core = { module = "androidx.test:core", version.ref = "androidxTest" }
@@ -46,6 +48,7 @@ vanniktech-mavenPublish = { id = "com.vanniktech.maven.publish", version.ref = "
 spotless = { id = "com.diffplug.spotless", version.ref = "spotless" }
 binaryCompatibilityValidator = { id = "org.jetbrains.kotlinx.binary-compatibility-validator", version.ref = "binaryCompatibilityValidator" }
 kotest = { id = "io.kotest", version.ref = "kotest" }
+testballoon = { id = "de.infix.testBalloon", version.ref = "testballoon" }
 ksp = { id = "com.google.devtools.ksp", version.ref = "ksp" }
 android-application = { id = "com.android.application", version.ref = "agp" }
 composeMultiplatform = { id = "org.jetbrains.compose", version.ref = "composeMultiplatform" }

jindong-compose/build.gradle.kts

@@ -21,6 +21,7 @@ plugins {
     alias(libs.plugins.compose.compiler)
     alias(libs.plugins.vanniktech.mavenPublish)
     alias(libs.plugins.kotest)
+    alias(libs.plugins.testballoon)
     alias(libs.plugins.ksp)
     alias(libs.plugins.binaryCompatibilityValidator)
 }
@@ -71,6 +72,8 @@ kotlin {
             implementation(libs.kotest.assertions.core)
             implementation(libs.compose.ui.test)
             implementation(libs.kotlinx.coroutines.test)
+            // PoC: TestBalloon running alongside Kotest in the same source set.
+            implementation(libs.testballoon.framework.core)
         }
     }
 }

jindong-compose/src/commonTest/kotlin/io/github/compose/jindong/compose/JindongApplierTest.kt

@@ -18,40 +18,38 @@
 package io.github.compose.jindong.compose
 
 import androidx.compose.runtime.ExperimentalComposeApi
+import de.infix.testBalloon.framework.core.testSuite
 import io.github.compose.jindong.core.element.HapticElement
 import io.github.compose.jindong.core.element.SequenceElement
 import io.github.compose.jindong.core.element.VibrationElement
 import io.github.compose.jindong.core.model.HapticIntensity
 import io.kotest.assertions.throwables.shouldThrow
-import io.kotest.core.spec.style.FunSpec
 import io.kotest.matchers.collections.shouldBeEmpty
 import io.kotest.matchers.collections.shouldContainExactly
 import io.kotest.matchers.shouldBe
 
 /**
- * Tests for [JindongApplier] using Kotest FunSpec.
+ * PoC migration of the former Kotest `JindongApplierTest` (FunSpec) to TestBalloon.
  *
- * Verifies correct tree manipulation operations:
- * - Insert (top-down and bottom-up)
- * - Remove (single and multiple elements)
- * - Move (forward, backward, multiple elements)
- * - Clear
- * - Navigation (down/up)
+ * The `lateinit var root/applier` + `beforeEach` pattern is replaced by a single `testFixture`. Bound
+ * with `asContextForEach`, every test — including those in nested suites — receives a freshly built
+ * [Fixture] as its receiver, so `root`/`applier` read exactly as they did before while the isolation
+ * is now structural rather than a re-init hook that has to run first. Assertions stay on
+ * kotest-assertions-core, so only the spec engine changed.
+ *
+ * Covers the same tree operations: insert (top-down), remove, move, clear, navigation, edge cases.
  */
-class JindongApplierTest :
-  FunSpec({
-
-    fun createElement(durationMs: Long): VibrationElement = VibrationElement(durationMs = durationMs, intensity = HapticIntensity.HIGH)
+val JindongApplierTest by testSuite {
 
-    lateinit var root: HapticElement
-    lateinit var applier: JindongApplier
+  fun createElement(durationMs: Long): VibrationElement = VibrationElement(durationMs = durationMs, intensity = HapticIntensity.HIGH)
 
-    beforeEach {
-      root = SequenceElement()
-      applier = JindongApplier(root)
-    }
+  class Fixture {
+    val root: HapticElement = SequenceElement()
+    val applier = JindongApplier(root)
+  }
 
-    context("JindongApplier insertTopDown") {
+  testFixture { Fixture() } asContextForEach {
+    testSuite("JindongApplier insertTopDown") {
       test("should add element at index 0") {
         val element = createElement(100)
 
@@ -93,7 +91,7 @@ class JindongApplierTest :
       }
     }
 
-    context("JindongApplier remove") {
+    testSuite("JindongApplier remove") {
       test("should remove single element at index") {
         val element1 = createElement(100)
         val element2 = createElement(200)
@@ -142,8 +140,8 @@ class JindongApplierTest :
       }
     }
 
-    context("JindongApplier move") {
-      context("moving single element") {
+    testSuite("JindongApplier move") {
+      testSuite("moving single element") {
         test("should move element forward") {
           val element1 = createElement(100)
           val element2 = createElement(200)
@@ -199,7 +197,7 @@ class JindongApplierTest :
         }
       }
 
-      context("moving multiple elements") {
+      testSuite("moving multiple elements") {
         test("should move multiple elements forward") {
           val elements = (1..5).map { createElement(it * 100L) }
           elements.forEach { applier.insertTopDown(root.children.size, it) }
@@ -240,7 +238,7 @@ class JindongApplierTest :
         }
       }
 
-      context("complex move scenarios") {
+      testSuite("complex move scenarios") {
         test("should handle sequential move operations correctly") {
           val elements = (1..7).map { createElement(it * 100L) }
           elements.forEach { applier.insertTopDown(root.children.size, it) }
@@ -263,7 +261,7 @@ class JindongApplierTest :
       }
     }
 
-    context("JindongApplier clear") {
+    testSuite("JindongApplier clear") {
       test("should remove all children from root") {
         val element1 = createElement(100)
         val element2 = createElement(200)
@@ -289,7 +287,7 @@ class JindongApplierTest :
       }
     }
 
-    context("JindongApplier navigation") {
+    testSuite("JindongApplier navigation") {
       test("should navigate down and up correctly") {
         val containerElement = SequenceElement()
         val leafElement = createElement(100)
@@ -330,7 +328,7 @@ class JindongApplierTest :
       }
     }
 
-    context("JindongApplier edge cases") {
+    testSuite("JindongApplier edge cases") {
       test("should handle empty operations on empty root") {
         root.children.shouldBeEmpty()
 
@@ -364,4 +362,5 @@ class JindongApplierTest :
         root.children.shouldBeEmpty()
       }
     }
-  })
+  }
+}

jindong-core/build.gradle.kts

@@ -20,6 +20,7 @@ plugins {
   alias(libs.plugins.android.kotlin.multiplatform.library)
   alias(libs.plugins.vanniktech.mavenPublish)
   alias(libs.plugins.kotest)
+  alias(libs.plugins.testballoon)
   alias(libs.plugins.ksp)
   alias(libs.plugins.binaryCompatibilityValidator)
   alias(libs.plugins.kover)
@@ -70,6 +71,8 @@ kotlin {
       implementation(libs.kotest.framework.engine)
       implementation(libs.kotest.assertions.core)
       implementation(libs.kotest.property)
+      // PoC: TestBalloon running alongside Kotest in the same source set.
+      implementation(libs.testballoon.framework.core)
     }
 
     named("androidHostTest").dependencies {

jindong-core/src/commonTest/kotlin/io/github/compose/jindong/core/model/HapticIntensityTest.kt

@@ -15,44 +15,48 @@
  */
 package io.github.compose.jindong.core.model
 
-import io.kotest.core.spec.style.FunSpec
+import de.infix.testBalloon.framework.core.testSuite
 import io.kotest.matchers.shouldBe
 
-class HapticIntensityTest :
-  FunSpec({
-    context("Pre-defined levels") {
-      test("LIGHT should have value 0.25") {
-        HapticIntensity.LIGHT.value shouldBe 0.25f
-      }
-      test("MEDIUM should have value 0.5") {
-        HapticIntensity.MEDIUM.value shouldBe 0.5f
-      }
-      test("STRONG should have value 0.75") {
-        HapticIntensity.STRONG.value shouldBe 0.75f
-      }
-      test("HIGH should have value 1.0") {
-        HapticIntensity.HIGH.value shouldBe 1.0f
+/**
+ * PoC migration of the former Kotest `HapticIntensityTest` (FunSpec) to TestBalloon.
+ *
+ * The data-driven cases previously sat as several `shouldBe` calls inside one test body, where the
+ * first failing input aborts the rest and the test name says nothing about which input broke. Each
+ * input is now its own test: a plain Kotlin `for` loop over `test(...)` is all TestBalloon needs for
+ * parameterization. Assertions stay on kotest-assertions-core (`shouldBe`), so only the spec engine
+ * changed.
+ */
+val HapticIntensityTest by testSuite {
+  testSuite("Pre-defined levels") {
+    val levels = listOf(
+      Triple("LIGHT", HapticIntensity.LIGHT, 0.25f),
+      Triple("MEDIUM", HapticIntensity.MEDIUM, 0.5f),
+      Triple("STRONG", HapticIntensity.STRONG, 0.75f),
+      Triple("HIGH", HapticIntensity.HIGH, 1.0f),
+    )
+    for ((name, level, expected) in levels) {
+      test("$name should have value $expected") {
+        level.value shouldBe expected
       }
     }
+  }
 
-    context("Custom intensity") {
-      test("should coerce values above 1.0 to 1.0") {
-        HapticIntensity.Custom(1.5f).value shouldBe 1.0f
-        HapticIntensity.Custom(2.0f).value shouldBe 1.0f
-        HapticIntensity.Custom(100f).value shouldBe 1.0f
+  testSuite("Custom intensity") {
+    for (input in listOf(1.5f, 2.0f, 100f)) {
+      test("should coerce $input above 1.0 to 1.0") {
+        HapticIntensity.Custom(input).value shouldBe 1.0f
       }
-
-      test("should coerce values below 0.0 to 0.0") {
-        HapticIntensity.Custom(-0.1f).value shouldBe 0.0f
-        HapticIntensity.Custom(-1.0f).value shouldBe 0.0f
-        HapticIntensity.Custom(-100f).value shouldBe 0.0f
+    }
+    for (input in listOf(-0.1f, -1.0f, -100f)) {
+      test("should coerce $input below 0.0 to 0.0") {
+        HapticIntensity.Custom(input).value shouldBe 0.0f
       }
-
-      test("should preserve valid values") {
-        HapticIntensity.Custom(0.0f).value shouldBe 0.0f
-        HapticIntensity.Custom(0.5f).value shouldBe 0.5f
-        HapticIntensity.Custom(1.0f).value shouldBe 1.0f
-        HapticIntensity.Custom(0.33f).value shouldBe 0.33f
+    }
+    for (input in listOf(0.0f, 0.5f, 1.0f, 0.33f)) {
+      test("should preserve valid value $input") {
+        HapticIntensity.Custom(input).value shouldBe input
       }
     }
-  })
+  }
+}