Allow tests to System.exit() by default

Otherwise the ApplicationContext stays alive and if it's a
server app the JVM does not exit at the end of "spring test".
User can override with "spring test foo.groovy --nohup"
(which we have to do in our unit tests).

.gitignore

@@ -13,6 +13,7 @@ build
 lib/
 target
 .springBeans
+interpolated*.xml
 dependency-reduced-pom.xml
 build.log
 _site/

spring-boot-cli/src/main/java/org/springframework/boot/cli/SpringCli.java

@@ -50,6 +50,7 @@ public class SpringCli {
 
 		int exitCode = runner.runAndHandleErrors(args);
 		if (exitCode != 0) {
+			// If successful, leave it to run in case it's a server app
 			System.exit(exitCode);
 		}
 	}

spring-boot-cli/src/main/java/org/springframework/boot/cli/command/test/TestCommand.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.cli.command.test;
 
 import joptsimple.OptionSet;
+import joptsimple.OptionSpec;
 
 import org.springframework.boot.cli.command.Command;
 import org.springframework.boot.cli.command.OptionParsingCommand;
@@ -45,6 +46,12 @@ public class TestCommand extends OptionParsingCommand {
 
 		private TestRunner runner;
 
+		@Override
+		protected void doOptions() {
+			option("nohup",
+					"Flag to indicate that the JVM should not exit when tests are finished");
+		}
+
 		@Override
 		protected void run(OptionSet options) throws Exception {
 			SourceOptions sourceOptions = new SourceOptions(options);
@@ -53,6 +60,9 @@ public class TestCommand extends OptionParsingCommand {
 			this.runner = new TestRunner(configuration, sourceOptions.getSourcesArray(),
 					sourceOptions.getArgsArray());
 			this.runner.compileAndRunTests();
+			if (!options.has("nohup")) {
+				System.exit(0); // TODO: non-zero if test fails?
+			}
 		}
 
 		/**

spring-boot-cli/src/test/java/org/springframework/boot/cli/CliTester.java

@@ -75,7 +75,10 @@ public class CliTester implements TestRule {
 	}
 
 	public String test(String... args) throws Exception {
-		Future<TestCommand> future = submitCommand(new TestCommand(), args);
+		String[] argsToUse = new String[args.length + 1];
+		System.arraycopy(args, 0, argsToUse, 1, args.length);
+		argsToUse[0] = "--nohup";
+		Future<TestCommand> future = submitCommand(new TestCommand(), argsToUse);
 		this.commands.add(future.get(this.timeout, TimeUnit.MILLISECONDS));
 		return getOutput();
 	}