Allow testcontainer beans to also contribute properties

Allow `Container` bean definitions to inject a `DynamicPropertyRegistry`
so that they can contribute environment properties.

Closes gh-35201

spring-boot-project/spring-boot-testcontainers/src/test/java/org/springframework/boot/testcontainers/properties/TestcontainersPropertySourceAutoConfigurationTests.java

@@ -0,0 +1,86 @@
+/*
+ * Copyright 2012-2023 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.boot.testcontainers.properties;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.boot.testcontainers.lifecycle.TestcontainersLifecycleApplicationContextInitializer;
+import org.springframework.boot.testsupport.testcontainers.RedisContainer;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+import org.springframework.test.context.DynamicPropertyRegistry;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link TestcontainersPropertySourceAutoConfiguration}.
+ *
+ * @author Phillip Webb
+ */
+class TestcontainersPropertySourceAutoConfigurationTests {
+
+	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+		.withInitializer(new TestcontainersLifecycleApplicationContextInitializer())
+		.withConfiguration(AutoConfigurations.of(TestcontainersPropertySourceAutoConfiguration.class));
+
+	@Test
+	void containerBeanMethodContributesProperties() {
+		this.contextRunner.withUserConfiguration(ContainerAndPropertiesConfiguration.class).run((context) -> {
+			TestBean testBean = context.getBean(TestBean.class);
+			RedisContainer redisContainer = context.getBean(RedisContainer.class);
+			assertThat(testBean.getUsingPort()).isEqualTo(redisContainer.getFirstMappedPort());
+		});
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@EnableConfigurationProperties(ContainerProperties.class)
+	@Import(TestBean.class)
+	static class ContainerAndPropertiesConfiguration {
+
+		@Bean
+		RedisContainer redisContainer(DynamicPropertyRegistry properties) {
+			RedisContainer container = new RedisContainer();
+			properties.add("container.port", container::getFirstMappedPort);
+			return container;
+		}
+
+	}
+
+	@ConfigurationProperties("container")
+	static record ContainerProperties(int port) {
+	}
+
+	static class TestBean {
+
+		private int usingPort;
+
+		TestBean(ContainerProperties containerProperties) {
+			this.usingPort = containerProperties.port();
+		}
+
+		int getUsingPort() {
+			return this.usingPort;
+		}
+
+	}
+
+}

spring-boot-project/spring-boot-testcontainers/src/test/java/org/springframework/boot/testcontainers/properties/TestcontainersPropertySourceTests.java

@@ -0,0 +1,104 @@
+/*
+ * Copyright 2012-2023 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.boot.testcontainers.properties;
+
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.core.env.EnumerablePropertySource;
+import org.springframework.core.env.PropertySource;
+import org.springframework.mock.env.MockEnvironment;
+import org.springframework.test.context.DynamicPropertyRegistry;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
+/**
+ * Tests for {@link TestcontainersPropertySource}.
+ *
+ * @author Phillip Webb
+ */
+class TestcontainersPropertySourceTests {
+
+	private MockEnvironment environment = new MockEnvironment();
+
+	@Test
+	void getPropertyWhenHasValueSupplierReturnsSuppliedValue() {
+		DynamicPropertyRegistry registry = TestcontainersPropertySource.attach(this.environment);
+		registry.add("test", () -> "spring");
+		assertThat(this.environment.getProperty("test")).isEqualTo("spring");
+	}
+
+	@Test
+	void getPropertyWhenHasNoValueSupplierReturnsNull() {
+		DynamicPropertyRegistry registry = TestcontainersPropertySource.attach(this.environment);
+		registry.add("test", () -> "spring");
+		assertThat(this.environment.getProperty("missing")).isNull();
+	}
+
+	@Test
+	void containsPropertyWhenHasPropertyReturnsTrue() {
+		DynamicPropertyRegistry registry = TestcontainersPropertySource.attach(this.environment);
+		registry.add("test", () -> null);
+		assertThat(this.environment.containsProperty("test")).isTrue();
+	}
+
+	@Test
+	void containsPropertyWhenHasNoPropertyReturnsFalse() {
+		DynamicPropertyRegistry registry = TestcontainersPropertySource.attach(this.environment);
+		registry.add("test", () -> null);
+		assertThat(this.environment.containsProperty("missing")).isFalse();
+	}
+
+	@Test
+	void getPropertyNamesReturnsNames() {
+		DynamicPropertyRegistry registry = TestcontainersPropertySource.attach(this.environment);
+		registry.add("test", () -> null);
+		registry.add("other", () -> null);
+		EnumerablePropertySource<?> propertySource = (EnumerablePropertySource<?>) this.environment.getPropertySources()
+			.get(TestcontainersPropertySource.NAME);
+		assertThat(propertySource.getPropertyNames()).containsExactly("test", "other");
+	}
+
+	@Test
+	@SuppressWarnings("unchecked")
+	void getSourceReturnsImmutableSource() {
+		TestcontainersPropertySource.attach(this.environment);
+		PropertySource<?> propertySource = this.environment.getPropertySources().get(TestcontainersPropertySource.NAME);
+		Map<String, Object> map = (Map<String, Object>) propertySource.getSource();
+		assertThatExceptionOfType(UnsupportedOperationException.class).isThrownBy(map::clear);
+	}
+
+	@Test
+	void attachWhenNotAttachedAttaches() {
+		TestcontainersPropertySource.attach(this.environment);
+		PropertySource<?> propertySource = this.environment.getPropertySources().get(TestcontainersPropertySource.NAME);
+		assertThat(propertySource).isNotNull();
+	}
+
+	@Test
+	void attachWhenAlreadyAttachedReturnsExisting() {
+		DynamicPropertyRegistry r1 = TestcontainersPropertySource.attach(this.environment);
+		PropertySource<?> p1 = this.environment.getPropertySources().get(TestcontainersPropertySource.NAME);
+		DynamicPropertyRegistry r2 = TestcontainersPropertySource.attach(this.environment);
+		PropertySource<?> p2 = this.environment.getPropertySources().get(TestcontainersPropertySource.NAME);
+		assertThat(r1).isSameAs(r2);
+		assertThat(p1).isSameAs(p2);
+	}
+
+}