Inline lambdas passed to assertThrows to support suspending functions

Resolves #1851.
junit-team · Mar 19, 2020 · c82acf3 · c82acf3
1 parent dd98521
commit c82acf3
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Showing 5 changed files with 22 additions and 5 deletions.
diff --git a/buildSrc/src/main/kotlin/Versions.kt b/buildSrc/src/main/kotlin/Versions.kt
@@ -18,6 +18,7 @@ object Versions {
     val bartholdy = "0.2.3"
     val classgraph = "4.8.59"
     val commonsIo = "2.6"
+    val coroutines = "1.3.3"
     val groovy = "3.0.0-rc-2"
     val log4j = "2.12.1"
     val mockito = "3.2.4"

diff --git a/dependencies/dependencies.gradle.kts b/dependencies/dependencies.gradle.kts
@@ -25,5 +25,6 @@ dependencies {
 		api("com.tngtech.archunit:archunit-junit5-api:${Versions.archunit}")
 		api("com.tngtech.archunit:archunit-junit5-engine:${Versions.archunit}")
 		api("org.slf4j:slf4j-jdk14:${Versions.slf4j}")
+		api("org.jetbrains.kotlinx:kotlinx-coroutines-core:${Versions.coroutines}")
 	}
 }
diff --git a/junit-jupiter-api/src/main/kotlin/org/junit/jupiter/api/Assertions.kt b/junit-jupiter-api/src/main/kotlin/org/junit/jupiter/api/Assertions.kt
@@ -95,8 +95,11 @@ fun assertAll(heading: String?, vararg executables: () -> Unit) =
  * ```
  * @see Assertions.assertThrows
  */
-inline fun <reified T : Throwable> assertThrows(noinline executable: () -> Unit): T =
-    Assertions.assertThrows(T::class.java, Executable(executable))
+inline fun <reified T : Throwable> assertThrows(executable: () -> Unit): T {
+    val result = runCatching(executable)
+
+    return Assertions.assertThrows(T::class.java) { result.getOrThrow() }
+}
 
 /**
  * Example usage:
@@ -108,7 +111,7 @@ inline fun <reified T : Throwable> assertThrows(noinline executable: () -> Unit)
  * ```
  * @see Assertions.assertThrows
  */
-inline fun <reified T : Throwable> assertThrows(message: String, noinline executable: () -> Unit): T =
+inline fun <reified T : Throwable> assertThrows(message: String, executable: () -> Unit): T =
     assertThrows({ message }, executable)
 
 /**
@@ -121,8 +124,11 @@ inline fun <reified T : Throwable> assertThrows(message: String, noinline execut
  * ```
  * @see Assertions.assertThrows
  */
-inline fun <reified T : Throwable> assertThrows(noinline message: () -> String, noinline executable: () -> Unit): T =
-    Assertions.assertThrows(T::class.java, Executable(executable), Supplier(message))
+inline fun <reified T : Throwable> assertThrows(noinline message: () -> String, executable: () -> Unit): T {
+    val result = runCatching(executable)
+
+    return Assertions.assertThrows(T::class.java, Executable { result.getOrThrow() }, Supplier(message))
+}
 
 /**
  * Example usage:

diff --git a/junit-jupiter-engine/junit-jupiter-engine.gradle.kts b/junit-jupiter-engine/junit-jupiter-engine.gradle.kts
@@ -19,5 +19,6 @@ dependencies {
 	testImplementation(project(":junit-platform-runner"))
 	testImplementation(project(":junit-platform-testkit"))
 	testImplementation("org.jetbrains.kotlin:kotlin-stdlib")
+	testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-core")
 	testImplementation("org.codehaus.groovy:groovy-all")
 }
diff --git a/junit-jupiter-engine/src/test/kotlin/org/junit/jupiter/api/KotlinAssertionsTests.kt b/junit-jupiter-engine/src/test/kotlin/org/junit/jupiter/api/KotlinAssertionsTests.kt
@@ -11,6 +11,7 @@ package org.junit.jupiter.api
 
 import java.util.stream.Stream
 import kotlin.reflect.KClass
+import kotlinx.coroutines.runBlocking
 import org.junit.jupiter.api.AssertionTestUtils.assertMessageEquals
 import org.junit.jupiter.api.AssertionTestUtils.assertMessageStartsWith
 import org.junit.jupiter.api.AssertionTestUtils.expectAssertionFailedError
@@ -60,6 +61,13 @@ class KotlinAssertionsTests {
         assertThrows<AssertionError>({ "should fail" }) { fail(null as Throwable?) }
     }
 
+    @Test
+    fun `expected context exception testing`() = runBlocking<Unit> {
+        assertThrows<AssertionError>("Should fail async") {
+            suspend { fail("Should fail async") }()
+        }
+    }
+
     @TestFactory
     fun assertDoesNotThrow(): Stream<out DynamicNode> = Stream.of(
         dynamicContainer("succeeds when no exception thrown", Stream.of(