Optionally close context after command logic

- spring.shell.context.close=true adds ApplicationListerner
  which attempts to close context with ApplicationReadyEvent.
- Relates #863

spring-shell-autoconfigure/src/main/java/org/springframework/shell/boot/ApplicationRunnerAutoConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2021 the original author or authors.
+ * Copyright 2021-2023 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.
@@ -19,7 +19,10 @@ import java.util.List;
 
 import org.springframework.boot.autoconfigure.AutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.boot.context.event.ApplicationReadyEvent;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.ApplicationListener;
 import org.springframework.context.annotation.Bean;
 import org.springframework.shell.DefaultShellApplicationRunner;
 import org.springframework.shell.ShellApplicationRunner;
@@ -34,4 +37,20 @@ public class ApplicationRunnerAutoConfiguration {
 	public DefaultShellApplicationRunner defaultShellApplicationRunner(List<ShellRunner> shellRunners) {
 		return new DefaultShellApplicationRunner(shellRunners);
 	}
+
+	@Bean
+	@ConditionalOnProperty(prefix = "spring.shell.context", name = "close", havingValue = "true")
+	public ApplicationReadyEventListener applicationReadyEventListener() {
+		return new ApplicationReadyEventListener();
+	}
+
+	static class ApplicationReadyEventListener implements ApplicationListener<ApplicationReadyEvent>{
+
+		@Override
+		public void onApplicationEvent(ApplicationReadyEvent event) {
+			// request context close after application runners so that
+			// shell exits in case that context is kept alive
+			event.getApplicationContext().close();
+		}
+	}
 }

spring-shell-autoconfigure/src/main/java/org/springframework/shell/boot/SpringShellProperties.java

@@ -34,6 +34,7 @@ public class SpringShellProperties {
 	private Command command = new Command();
 	private Help help = new Help();
 	private Option option = new Option();
+	private Context context = new Context();
 
 	public void setConfig(Config config) {
 		this.config = config;
@@ -107,6 +108,14 @@ public class SpringShellProperties {
 		this.option = option;
 	}
 
+	public Context getContext() {
+		return context;
+	}
+
+	public void setContext(Context context) {
+		this.context = context;
+	}
+
 	public static class Config {
 
 		private String env;
@@ -603,6 +612,19 @@ public class SpringShellProperties {
 		}
 	}
 
+	public static class Context {
+
+		private boolean close = false;
+
+		public boolean isClose() {
+			return close;
+		}
+
+		public void setClose(boolean close) {
+			this.close = close;
+		}
+	}
+
 	public static enum OptionNamingCase {
 		NOOP,
 		CAMEL,

spring-shell-autoconfigure/src/test/java/org/springframework/shell/boot/ApplicationRunnerAutoConfigurationTests.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 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.shell.boot;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class ApplicationRunnerAutoConfigurationTests {
+
+	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+			.withConfiguration(AutoConfigurations.of(ApplicationRunnerAutoConfiguration.class));
+
+	@Test
+	void contextCloseDisabledByDefault() {
+		contextRunner.run(context -> assertThat(context)
+				.doesNotHaveBean(ApplicationRunnerAutoConfiguration.ApplicationReadyEventListener.class));
+	}
+
+	@Test
+	void contextCloseEnabled() {
+		contextRunner.withPropertyValues("spring.shell.context.close:true")
+				.run(context -> assertThat(context)
+				.hasSingleBean(ApplicationRunnerAutoConfiguration.ApplicationReadyEventListener.class));
+	}
+
+}

spring-shell-autoconfigure/src/test/java/org/springframework/shell/boot/SpringShellPropertiesTests.java

@@ -70,6 +70,7 @@ public class SpringShellPropertiesTests {
 					assertThat(properties.getHelp().getLongNames()).containsExactly("help");
 					assertThat(properties.getHelp().getShortNames()).containsExactly('h');
 					assertThat(properties.getOption().getNaming().getCaseType()).isEqualTo(OptionNamingCase.NOOP);
+					assertThat(properties.getContext().isClose()).isFalse();
 				});
 	}
 
@@ -112,6 +113,7 @@ public class SpringShellPropertiesTests {
 				.withPropertyValues("spring.shell.help.long-names=fake")
 				.withPropertyValues("spring.shell.help.short-names=f")
 				.withPropertyValues("spring.shell.option.naming.case-type=camel")
+				.withPropertyValues("spring.shell.context.close=true")
 				.withUserConfiguration(Config1.class)
 				.run((context) -> {
 					SpringShellProperties properties = context.getBean(SpringShellProperties.class);
@@ -151,6 +153,7 @@ public class SpringShellPropertiesTests {
 					assertThat(properties.getHelp().getLongNames()).containsExactly("fake");
 					assertThat(properties.getHelp().getShortNames()).containsExactly('f');
 					assertThat(properties.getOption().getNaming().getCaseType()).isEqualTo(OptionNamingCase.CAMEL);
+					assertThat(properties.getContext().isClose()).isTrue();
 				});
 	}