Add Kotlin documentation and tests for @DynamicPropertySource

See gh-24540

Author: sdeleuze

spring-test/src/test/kotlin/org/springframework/test/context/KotlinDynamicPropertySourceIntegrationTests.kt

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2002-2020 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.
+ */
+package org.springframework.test.context
+
+import org.assertj.core.api.Assertions
+import org.junit.jupiter.api.Test
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.beans.factory.annotation.Value
+import org.springframework.context.annotation.Configuration
+import org.springframework.context.annotation.Import
+import org.springframework.stereotype.Component
+import org.springframework.test.context.junit.jupiter.SpringJUnitConfig
+
+/**
+ * Kotlin integration test for [@DynamicPropertySource][DynamicPropertySource].
+ *
+ * @author Sebastien Deleuze
+ * @author Phillip Webb
+ * @author Sam Brannen
+ */
+@SpringJUnitConfig
+class KotlinDynamicPropertySourceIntegrationTests {
+
+	@Test
+	fun hasInjectedValues(@Autowired service: Service) {
+		Assertions.assertThat(service.ip).isEqualTo("127.0.0.1")
+		Assertions.assertThat(service.port).isEqualTo(4242)
+	}
+
+	@Configuration
+	@Import(Service::class)
+	open class Config
+
+	@Component
+	class Service(@Value("\${test.container.ip}") val ip: String, @Value("\${test.container.port}") val port: Int)
+
+	class DemoContainer(val ipAddress: String = "127.0.0.1", val port: Int = 4242)
+
+	companion object {
+
+		@JvmStatic
+		val container = DemoContainer()
+
+		@DynamicPropertySource
+		@JvmStatic
+		fun containerProperties(registry: DynamicPropertyRegistry) {
+			registry.add("test.container.ip") { container.ipAddress }
+			registry.add("test.container.port") { container.port }
+		}
+	}
+}

src/docs/asciidoc/testing.adoc

@@ -4010,6 +4010,31 @@ via `@Value("${redis.host}")` and `@Value("${redis.port}")`, respectively.
 
 	}
 ----
+[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
+.Kotlin
+----
+	@SpringJUnitConfig(/* ... */)
+	@Testcontainers
+	class ExampleIntegrationTests {
+
+		companion object {
+
+			@Container
+			@JvmStatic
+			val redis: RedisContainer = RedisContainer()
+
+			@DynamicPropertySource
+			@JvmStatic
+			fun redisProperties(registry: DynamicPropertyRegistry) {
+				registry.add("redis.host", redis::getContainerIpAddress)
+				registry.add("redis.port", redis::getMappedPort)
+			}
+		}
+
+		// tests ...
+
+	}
+----
 
 [[testcontext-ctx-management-web]]
 ===== Loading a `WebApplicationContext`