Improve ContextFunctionCatalogAutoConfiguration conditional loading

- Allow custom AvroSchemaServiceManager to be used
- Make AvroSchemaMessageConverter bean method specifically typed
- Make CloudEventsMessageConverter bean method specifically typed
- Add tests focusing on the conditional loading aspects of the auto configuration

Fixes gh-797
Resolves #814

spring-cloud-function-context/src/test/java/org/springframework/cloud/function/context/config/ContextFunctionCatalogAutoConfigurationConditionalLoadingTests.java

@@ -0,0 +1,136 @@
+/*
+ * Copyright 2022-2022 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.cloud.function.context.config;
+
+import io.cloudevents.spring.messaging.CloudEventMessageConverter;
+import org.apache.avro.Schema;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.test.context.FilteredClassLoader;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.cloud.function.context.FunctionCatalog;
+import org.springframework.cloud.function.context.FunctionRegistry;
+import org.springframework.cloud.function.context.converter.avro.AvroSchemaMessageConverter;
+import org.springframework.cloud.function.context.converter.avro.AvroSchemaServiceManager;
+import org.springframework.cloud.function.context.scan.TestFunction;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Tests the conditional loading aspects of the {@link ContextFunctionCatalogAutoConfiguration}.
+ *
+ * @author Chris Bono
+ */
+public class ContextFunctionCatalogAutoConfigurationConditionalLoadingTests {
+
+	protected final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+		.withConfiguration(AutoConfigurations.of(ContextFunctionCatalogAutoConfiguration.class));
+
+	@Test
+	void autoConfigDisabledWhenCustomFunctionCatalogExists() {
+		contextRunner.withBean(FunctionCatalog.class, () -> mock(FunctionCatalog.class))
+			.run((context) -> assertThat(context).doesNotHaveBean(FunctionRegistry.class));
+	}
+
+	@Nested
+	class AvroSchemaMessageConverterConfig {
+
+		@Test
+		void avroSchemaMessageConverterBeansLoadedWhenAvroOnClasspath() {
+			contextRunner.run((context) -> assertThat(context).hasSingleBean(AvroSchemaServiceManager.class)
+				.hasSingleBean(AvroSchemaMessageConverter.class));
+		}
+
+		@Test
+		void avroSchemaMessageConverterBeansNotLoadedWhenAvroNotOnClasspath() {
+			contextRunner.withClassLoader(new FilteredClassLoader(Schema.class)).run((context) ->
+				assertThat(context).doesNotHaveBean(AvroSchemaServiceManager.class)
+					.doesNotHaveBean(AvroSchemaMessageConverter.class));
+		}
+
+		@Test
+		void customAvroSchemaServiceManagerIsRespected() {
+			AvroSchemaServiceManager customManager = mock(AvroSchemaServiceManager.class);
+			contextRunner.withBean(AvroSchemaServiceManager.class, () -> customManager)
+				.run((context) -> assertThat(context).getBean(AvroSchemaServiceManager.class).isSameAs(customManager));
+		}
+
+		@Test
+		void customAvroSchemaMessageConverterIsRespected() {
+			AvroSchemaMessageConverter customConverter = mock(AvroSchemaMessageConverter.class);
+			contextRunner.withBean(AvroSchemaMessageConverter.class, () -> customConverter)
+				.run((context) -> assertThat(context).getBean(AvroSchemaMessageConverter.class).isSameAs(customConverter));
+		}
+	}
+
+	@Nested
+	class CloudEventsMessageConverterConfig {
+
+		@Test
+		void cloudEventsMessageConverterBeanLoadedWhenCloudEventsOnClasspath() {
+			contextRunner.run((context) -> assertThat(context).hasSingleBean(CloudEventMessageConverter.class));
+		}
+
+		@Test
+		void cloudEventsMessageConverterBeanNotLoadedWhenCloudEventsNotOnClasspath() {
+			contextRunner.withClassLoader(new FilteredClassLoader(CloudEventMessageConverter.class)).run((context) ->
+				assertThat(context).doesNotHaveBean(CloudEventMessageConverter.class));
+		}
+
+		@Test
+		void customCloudEventsMessageConverterIsRespected() {
+			CloudEventMessageConverter customConverter = mock(CloudEventMessageConverter.class);
+			contextRunner.withBean(CloudEventMessageConverter.class, () -> customConverter)
+				.run((context) -> assertThat(context).getBean(CloudEventMessageConverter.class).isSameAs(customConverter));
+		}
+	}
+
+	@Nested
+	class PlainFunctionScanConfig {
+
+		@Test
+		void functionScanConfigEnabledByDefault() {
+			contextRunner.withPropertyValues("spring.cloud.function.scan.packages:" + TestFunction.class.getPackageName())
+				.run((context) -> assertThat(context).hasSingleBean(TestFunction.class));
+		}
+
+		@Test
+		void functionScanConfigEnabledWhenEnabledPropertySetToTrue() {
+			contextRunner.withPropertyValues("spring.cloud.function.scan.packages:" + TestFunction.class.getPackageName(),
+					"spring.cloud.function.scan.enabled:true")
+				.run((context) -> assertThat(context).hasSingleBean(TestFunction.class));
+		}
+
+		@Test
+		void functionScanConfigEnabledWithScanPackagesPointingToNoFunctions() {
+			contextRunner.withPropertyValues("spring.cloud.function.scan.packages:" + TestFunction.class.getPackageName() + ".faux",
+					"spring.cloud.function.scan.enabled:true")
+				.run((context) -> assertThat(context).doesNotHaveBean(TestFunction.class));
+		}
+
+		@Test
+		void functionScanConfigDisabledWhenEnabledPropertySetToFalse() {
+			contextRunner.withPropertyValues("spring.cloud.function.scan.packages:" + TestFunction.class.getPackageName(),
+					"spring.cloud.function.scan.enabled:false")
+				.run((context) -> assertThat(context).doesNotHaveBean(TestFunction.class));
+		}
+
+	}
+}