Prevent double registration of commands

spring-shell-core/src/main/java/org/springframework/shell/ConfigurableCommandRegistry.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2017 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
+ *
+ *      http://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;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.TreeMap;
+
+/**
+ * A {@link CommandRegistry} that supports registration of new commands.
+ *
+ * <p>Makes sure that no two commands are registered with the same name.</p>
+ *
+ * @author Eric Bottard
+ */
+public class ConfigurableCommandRegistry implements CommandRegistry {
+
+	private Map<String, MethodTarget> commands = new HashMap<>();
+
+	@Override
+	public Map<String, MethodTarget> listCommands() {
+		return new TreeMap<>(commands);
+	}
+
+	public void register(String name, MethodTarget target) {
+		MethodTarget previous = commands.get(name);
+		if (previous != null) {
+			throw new IllegalArgumentException(
+				String.format("Illegal registration for command '%s': Attempt to register both '%s' and '%s'", name, target, previous));
+		}
+		commands.put(name, target);
+	}
+}

spring-shell-core/src/main/java/org/springframework/shell/MethodTargetRegistrar.java

@@ -16,19 +16,17 @@
 
 package org.springframework.shell;
 
-import java.util.Map;
-
 /**
- * Strategy interface for discovering commands.
+ * Strategy interface for registering commands.
  *
  * @author Eric Bottard
  * @author Camilo Gonzalez
  */
-public interface MethodTargetResolver {
+public interface MethodTargetRegistrar {
 
 	/**
-	 * Return a mapping from {@literal <command keyword(s)>} to actual behavior.
+	 * Register mappings from {@literal <command keyword(s)>} to actual behavior.
 	 */
-	public Map<String, MethodTarget> resolve();
+	void register(ConfigurableCommandRegistry registry);
 
 }

spring-shell-core/src/main/java/org/springframework/shell/Shell.java

@@ -33,8 +33,6 @@ import javax.validation.Validation;
 import javax.validation.executable.ExecutableValidator;
 
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.boot.ApplicationArguments;
-import org.springframework.boot.ApplicationRunner;
 import org.springframework.context.ApplicationContext;
 import org.springframework.core.MethodParameter;
 import org.springframework.util.ReflectionUtils;
@@ -80,9 +78,11 @@ public class Shell implements CommandRegistry {
 
 	@PostConstruct
 	public void gatherMethodTargets() throws Exception {
-		for (MethodTargetResolver resolver : applicationContext.getBeansOfType(MethodTargetResolver.class).values()) {
-			methodTargets.putAll(resolver.resolve());
+		ConfigurableCommandRegistry registry = new ConfigurableCommandRegistry();
+		for (MethodTargetRegistrar resolver : applicationContext.getBeansOfType(MethodTargetRegistrar.class).values()) {
+			resolver.register(registry);
 		}
+		methodTargets = registry.listCommands();
 	}
 
 	/**

spring-shell-core/src/test/java/org/springframework/shell/ConfigurableCommandRegistryTest.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2017 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
+ *
+ *      http://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;
+
+import static org.hamcrest.collection.IsMapContaining.hasEntry;
+import static org.hamcrest.collection.IsMapContaining.hasKey;
+import static org.junit.Assert.*;
+
+import org.hamcrest.collection.IsMapContaining;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+/**
+ * Unit tests for {@link ConfigurableCommandRegistry}.
+ *
+ * @author Eric Bottard
+ */
+public class ConfigurableCommandRegistryTest {
+
+	@Rule
+	public ExpectedException thrown= ExpectedException.none();
+
+	@Test
+	public void testRegistration() {
+		ConfigurableCommandRegistry registry = new ConfigurableCommandRegistry();
+		registry.register("foo", MethodTarget.of("toString", this, "some command"));
+
+		assertThat(registry.listCommands(), hasKey("foo"));
+	}
+
+	@Test
+	public void testDoubleRegistration() {
+		ConfigurableCommandRegistry registry = new ConfigurableCommandRegistry();
+		registry.register("foo", MethodTarget.of("toString", this, "some command"));
+
+		thrown.expect(IllegalArgumentException.class);
+		thrown.expectMessage("foo");
+		thrown.expectMessage("toString");
+		thrown.expectMessage("hashCode");
+
+		registry.register("foo", MethodTarget.of("hashCode", this, "some command"));
+	}
+
+}

spring-shell-samples/src/main/java/org/springframework/shell/samples/standard/Commands.java

@@ -35,7 +35,7 @@ import org.springframework.stereotype.Component;
  *
  * @author Eric Bottard
  */
-@ShellComponent("")
+@ShellComponent()
 public class Commands {
 
 	@ShellMethod(help = "a command whose name looks the same as another one", value = "help me out")

spring-shell-shell1-adapter/src/main/java/org/springframework/shell/legacy/LegacyAdapterAutoConfiguration.java

@@ -35,8 +35,8 @@ import org.springframework.shell.converters.SimpleFileConverter;
 public class LegacyAdapterAutoConfiguration {
 
 	@Bean
-	public LegacyMethodTargetResolver legacyMethodTargetResolver() {
-		return new LegacyMethodTargetResolver();
+	public LegacyMethodTargetRegistrar legacyMethodTargetResolver() {
+		return new LegacyMethodTargetRegistrar();
 	}
 
 	@Bean

spring-shell-shell1-adapter/src/main/java/org/springframework/shell/legacy/LegacyMethodTargetRegistrar.java

@@ -20,18 +20,20 @@ import static org.springframework.util.StringUtils.collectionToDelimitedString;
 
 import java.util.HashMap;
 import java.util.Map;
+import java.util.TreeMap;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.ApplicationContext;
+import org.springframework.shell.ConfigurableCommandRegistry;
 import org.springframework.shell.core.CommandMarker;
 import org.springframework.shell.core.annotation.CliCommand;
 import org.springframework.shell.MethodTarget;
-import org.springframework.shell.MethodTargetResolver;
+import org.springframework.shell.MethodTargetRegistrar;
 import org.springframework.stereotype.Component;
 import org.springframework.util.ReflectionUtils;
 
 /**
- * A {@link MethodTargetResolver} that discovers methods annotated with {@link CliCommand} on beans
+ * A {@link MethodTargetRegistrar} that discovers methods annotated with {@link CliCommand} on beans
  * implementing the {@link CommandMarker} marker interface.
  * 
  * @author Eric Bottard
@@ -39,31 +41,33 @@ import org.springframework.util.ReflectionUtils;
  * @author Camilo Gonzalez
  */
 @Component
-public class LegacyMethodTargetResolver implements MethodTargetResolver {
+public class LegacyMethodTargetRegistrar implements MethodTargetRegistrar {
 
 	@Autowired
 	private ApplicationContext applicationContext;
+
+	private Map<String, MethodTarget> commands = new TreeMap<>();
 	
 	@Override
-	public Map<String, MethodTarget> resolve() {
-		Map<String, MethodTarget> methodTargets = new HashMap<>();
+	public void register(ConfigurableCommandRegistry registry) {
 		Map<String, CommandMarker> beans = applicationContext.getBeansOfType(CommandMarker.class);
 		for (Object bean : beans.values()) {
 			Class<?> clazz = bean.getClass();
 			ReflectionUtils.doWithMethods(clazz, method -> {
 				CliCommand cliCommand = method.getAnnotation(CliCommand.class);
 				for (String key : cliCommand.value()) {
-					methodTargets.put(key, new MethodTarget(method, bean, cliCommand.help()));
+					MethodTarget target = new MethodTarget(method, bean, cliCommand.help());
+					registry.register(key, target);
+					commands.put(key, target);
 				}
 			}, method -> method.getAnnotation(CliCommand.class) != null);
 		}
-		return methodTargets;
 	}
 
 	@Override
 	public String toString() {
 		return getClass().getSimpleName() + " contributing "
-			+ collectionToDelimitedString(resolve().keySet(), ", ", "[", "]");
+			+ collectionToDelimitedString(commands.keySet(), ", ", "[", "]");
 	}
 
 }

spring-shell-shell1-adapter/src/test/java/org/springframework/shell/legacy/LegacyMethodTargetRegistrarTest.java

@@ -27,27 +27,32 @@ import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.shell.ConfigurableCommandRegistry;
 import org.springframework.shell.MethodTarget;
-import org.springframework.shell.MethodTargetResolver;
+import org.springframework.shell.MethodTargetRegistrar;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
 /**
- * Created by ericbottard on 09/12/15.
+ * Unit tests for {@link LegacyMethodTargetRegistrar}.
+ *
+ * @author Eric Bottard
  */
 @RunWith(SpringJUnit4ClassRunner.class)
-@ContextConfiguration(classes = LegacyMethodTargetResolverTest.Config.class)
-public class LegacyMethodTargetResolverTest {
+@ContextConfiguration(classes = LegacyMethodTargetRegistrarTest.Config.class)
+public class LegacyMethodTargetRegistrarTest {
 
 	@Autowired
 	private LegacyCommands legacyCommands;
 
 	@Autowired
-	private MethodTargetResolver resolver;
+	private MethodTargetRegistrar resolver;
 
 	@Test
 	public void findsMethodsAnnotatedWithCliCommand() throws Exception {
-		Map<String, MethodTarget> targets = resolver.resolve();
+		ConfigurableCommandRegistry registry = new ConfigurableCommandRegistry();
+		resolver.register(registry);
+		Map<String, MethodTarget> targets = registry.listCommands();
 
 		assertThat(targets).contains(entry(
 				"register module",
@@ -64,8 +69,8 @@ public class LegacyMethodTargetResolverTest {
 		}
 
 		@Bean
-		public MethodTargetResolver methodTargetResolver() {
-			return new LegacyMethodTargetResolver();
+		public MethodTargetRegistrar methodTargetResolver() {
+			return new LegacyMethodTargetRegistrar();
 		}
 	}
 

spring-shell-standard-commands/src/test/java/org/springframework/shell/standard/commands/StandardCommandsAutoConfigurationTest.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2017 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
+ *
+ *      http://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.standard.commands;
+
+/**
+ * Tests for {@link StandardCommandsAutoConfiguration}.
+ *
+ * @author Eric Bottard
+ */
+public class StandardCommandsAutoConfigurationTest {
+
+}

spring-shell-standard/src/main/java/org/springframework/shell/standard/StandardAPIAutoConfiguration.java

@@ -20,7 +20,7 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.shell.CommandRegistry;
-import org.springframework.shell.MethodTargetResolver;
+import org.springframework.shell.MethodTargetRegistrar;
 import org.springframework.shell.ParameterResolver;
 
 /**
@@ -42,8 +42,8 @@ public class StandardAPIAutoConfiguration {
 	}
 
 	@Bean
-	public MethodTargetResolver standardMethodTargetResolver() {
-		return new StandardMethodTargetResolver();
+	public MethodTargetRegistrar standardMethodTargetResolver() {
+		return new StandardMethodTargetRegistrar();
 	}
 
 	@Bean

spring-shell-standard/src/main/java/org/springframework/shell/standard/StandardMethodTargetRegistrar.java

@@ -23,27 +23,28 @@ import java.util.Map;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.ApplicationContext;
+import org.springframework.shell.ConfigurableCommandRegistry;
 import org.springframework.shell.MethodTarget;
-import org.springframework.shell.MethodTargetResolver;
-import org.springframework.stereotype.Component;
+import org.springframework.shell.MethodTargetRegistrar;
 import org.springframework.util.ReflectionUtils;
 
 /**
- * The standard implementation of {@link MethodTargetResolver} for new shell applications,
+ * The standard implementation of {@link MethodTargetRegistrar} for new shell applications,
  * resolves methods annotated with {@link ShellMethod} on {@link ShellComponent} beans.
  *
  * @author Eric Bottard
  * @author Florent Biville
  * @author Camilo Gonzalez
  */
-public class StandardMethodTargetResolver implements MethodTargetResolver {
+public class StandardMethodTargetRegistrar implements MethodTargetRegistrar {
 
 	@Autowired
 	private ApplicationContext applicationContext;
+
+	private Map<String, MethodTarget> commands = new HashMap<>();
 	
 	@Override
-	public Map<String, MethodTarget> resolve() {
-		Map<String, MethodTarget> methodTargets = new HashMap<>();
+	public void register(ConfigurableCommandRegistry registry) {
 		Map<String, Object> commandBeans = applicationContext.getBeansWithAnnotation(ShellComponent.class);
 		for (Object bean : commandBeans.values()) {
 			Class<?> clazz = bean.getClass();
@@ -54,16 +55,17 @@ public class StandardMethodTargetResolver implements MethodTargetResolver {
 					keys = new String[] {method.getName()};
 				}
 				for (String key : keys) {
-					methodTargets.put(key, new MethodTarget(method, bean, shellMapping.help()));
+					MethodTarget target = new MethodTarget(method, bean, shellMapping.help());
+					registry.register(key, target);
+					commands.put(key, target);
 				}
 			}, method -> method.getAnnotation(ShellMethod.class) != null);
 		}
-		return methodTargets;
 	}
 
 	@Override
 	public String toString() {
 		return getClass().getSimpleName() + " contributing "
-			+ collectionToDelimitedString(resolve().keySet(), ", ", "[", "]");
+			+ collectionToDelimitedString(commands.keySet(), ", ", "[", "]");
 	}
 }