Resolves #127: Prevent duplicate report outcomes

The collection of outcomes is a list. Sometimes a race condition causes to instances
of the same outcome to get added to the list shown in the report. By replacing this
with a set and propery equals/hashCode, duplicates are prevented from appearing
in the report.

I added test cases to prove that that POJO is properly managed inside a Set and also
to show that duplicates don't appear in the final report.

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/AutoConfigurationReport.java

@@ -16,13 +16,7 @@
 
 package org.springframework.boot.autoconfigure;
 
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Map;
-import java.util.SortedMap;
-import java.util.TreeMap;
+import java.util.*;
 
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
@@ -40,9 +34,7 @@ import org.springframework.context.annotation.Condition;
 public class AutoConfigurationReport {
 
 	private static final String BEAN_NAME = "autoConfigurationReport";
-
 	private final SortedMap<String, ConditionAndOutcomes> outcomes = new TreeMap<String, ConditionAndOutcomes>();
-
 	private AutoConfigurationReport parent;
 
 	/**
@@ -115,7 +107,7 @@ public class AutoConfigurationReport {
 	 */
 	public static class ConditionAndOutcomes implements Iterable<ConditionAndOutcome> {
 
-		private List<ConditionAndOutcome> outcomes = new ArrayList<ConditionAndOutcome>();
+		private Set<ConditionAndOutcome> outcomes = new HashSet<ConditionAndOutcome>();
 
 		public void add(Condition condition, ConditionOutcome outcome) {
 			this.outcomes.add(new ConditionAndOutcome(condition, outcome));
@@ -135,7 +127,7 @@ public class AutoConfigurationReport {
 
 		@Override
 		public Iterator<ConditionAndOutcome> iterator() {
-			return Collections.unmodifiableList(this.outcomes).iterator();
+			return Collections.unmodifiableSet(this.outcomes).iterator();
 		}
 
 	}
@@ -146,7 +138,6 @@ public class AutoConfigurationReport {
 	public static class ConditionAndOutcome {
 
 		private final Condition condition;
-
 		private final ConditionOutcome outcome;
 
 		public ConditionAndOutcome(Condition condition, ConditionOutcome outcome) {
@@ -161,6 +152,31 @@ public class AutoConfigurationReport {
 		public ConditionOutcome getOutcome() {
 			return this.outcome;
 		}
+
+		@Override
+		public boolean equals(Object o) {
+			if (this == o)
+				return true;
+			if (o == null || getClass() != o.getClass())
+				return false;
+
+			if (this.outcome == null || this.outcome.getMessage() == null) {
+				return false;
+			}
+
+			ConditionAndOutcome that = (ConditionAndOutcome) o;
+
+			if (that.getOutcome() == null || this.getOutcome().getMessage() == null) {
+				return false;
+			}
+
+			return this.getOutcome().getMessage().equals(that.getOutcome().getMessage());
+		}
+
+		@Override
+		public int hashCode() {
+			return outcome != null && outcome.getMessage() != null ? outcome.getMessage().hashCode() : 0;
+		}
     }
 
 }

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/AutoConfigurationReportTests.java

@@ -16,8 +16,10 @@
 
 package org.springframework.boot.autoconfigure;
 
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map;
+import java.util.Set;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -29,17 +31,19 @@ import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.boot.autoconfigure.AutoConfigurationReport.ConditionAndOutcome;
 import org.springframework.boot.autoconfigure.AutoConfigurationReport.ConditionAndOutcomes;
 import org.springframework.boot.autoconfigure.condition.ConditionOutcome;
+import org.springframework.boot.autoconfigure.web.MultipartAutoConfiguration;
 import org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Condition;
 import org.springframework.context.annotation.Import;
 
-import static org.hamcrest.Matchers.equalTo;
-import static org.hamcrest.Matchers.not;
-import static org.hamcrest.Matchers.nullValue;
-import static org.hamcrest.Matchers.sameInstance;
+import static org.hamcrest.Matchers.*;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
 import static org.mockito.BDDMockito.given;
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.mock;
 
 /**
  * Tests for {@link AutoConfigurationReport}.
@@ -88,8 +92,7 @@ public class AutoConfigurationReportTests {
 	@Test
 	public void parent() throws Exception {
 		this.beanFactory.setParentBeanFactory(new DefaultListableBeanFactory());
-		AutoConfigurationReport.get((ConfigurableListableBeanFactory) this.beanFactory
-				.getParentBeanFactory());
+		AutoConfigurationReport.get((ConfigurableListableBeanFactory) this.beanFactory.getParentBeanFactory());
 		assertThat(this.report,
 				sameInstance(AutoConfigurationReport.get(this.beanFactory)));
 		assertThat(this.report, not(nullValue()));
@@ -98,12 +101,15 @@ public class AutoConfigurationReportTests {
 
 	@Test
 	public void recordConditionEvaluations() throws Exception {
+		given(this.outcome1.getMessage()).willReturn("Message 1");
+		given(this.outcome2.getMessage()).willReturn("Message 2");
+		given(this.outcome3.getMessage()).willReturn("Message 3");
+
 		this.report.recordConditionEvaluation("a", this.condition1, this.outcome1);
 		this.report.recordConditionEvaluation("a", this.condition2, this.outcome2);
 		this.report.recordConditionEvaluation("b", this.condition3, this.outcome3);
 
-		Map<String, ConditionAndOutcomes> map = this.report
-				.getConditionAndOutcomesBySource();
+		Map<String, ConditionAndOutcomes> map = this.report.getConditionAndOutcomesBySource();
 		assertThat(map.size(), equalTo(2));
 		Iterator<ConditionAndOutcome> iterator = map.get("a").iterator();
 		ConditionAndOutcome conditionAndOutcome = iterator.next();
@@ -146,16 +152,102 @@ public class AutoConfigurationReportTests {
 	@Test
 	@SuppressWarnings("resource")
 	public void springBootConditionPopulatesReport() throws Exception {
-		AutoConfigurationReport report = AutoConfigurationReport
-				.get(new AnnotationConfigApplicationContext(Config.class)
-						.getBeanFactory());
+		AutoConfigurationReport report = AutoConfigurationReport.get(new AnnotationConfigApplicationContext(
+				Config.class).getBeanFactory());
 		assertThat(report.getConditionAndOutcomesBySource().size(), not(equalTo(0)));
 	}
 
+	@Test
+	public void testDuplicateConditionAndOutcomes() {
+		Condition condition1 = mock(Condition.class);
+		ConditionOutcome conditionOutcome1 = mock(ConditionOutcome.class);
+		given(conditionOutcome1.getMessage()).willReturn("This is message 1");
+
+		Condition condition2 = mock(Condition.class);
+		ConditionOutcome conditionOutcome2 = mock(ConditionOutcome.class);
+		given(conditionOutcome2.getMessage()).willReturn("This is message 2");
+
+		Condition condition3 = mock(Condition.class);
+		ConditionOutcome conditionOutcome3 = mock(ConditionOutcome.class);
+		given(conditionOutcome3.getMessage()).willReturn("This is message 2"); // identical in value to #2
+
+		ConditionAndOutcome outcome1 = new ConditionAndOutcome(condition1,
+				conditionOutcome1);
+		assertThat(outcome1, equalTo(outcome1));
+
+		ConditionAndOutcome outcome2 = new ConditionAndOutcome(condition2,
+				conditionOutcome2);
+		assertThat(outcome1, not(equalTo(outcome2)));
+
+		ConditionAndOutcome outcome3 = new ConditionAndOutcome(condition3,
+				conditionOutcome3);
+		assertThat(outcome2, equalTo(outcome3));
+
+		Set<ConditionAndOutcome> set = new HashSet<ConditionAndOutcome>();
+		set.add(outcome1);
+		set.add(outcome2);
+		set.add(outcome3);
+		assertThat(set.size(), equalTo(2));
+
+		ConditionAndOutcomes outcomes = new ConditionAndOutcomes();
+		outcomes.add(condition1, conditionOutcome1);
+		outcomes.add(condition2, conditionOutcome2);
+		outcomes.add(condition3, conditionOutcome3);
+
+		int i = 0;
+		Iterator<ConditionAndOutcome> iterator = outcomes.iterator();
+		while (iterator.hasNext()) {
+			i++;
+			iterator.next();
+		}
+		assertThat(i, equalTo(2));
+	}
+
+	@Test
+	public void duplicateOutcomes() {
+		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(
+				DuplicateConfig.class);
+		AutoConfigurationReport report = AutoConfigurationReport.get(context.getBeanFactory());
+		String autoconfigKey = "org.springframework.boot.autoconfigure.web.MultipartAutoConfiguration";
+
+		assertThat(report.getConditionAndOutcomesBySource().keySet(),
+				hasItem(autoconfigKey));
+
+		ConditionAndOutcomes conditionAndOutcomes = report.getConditionAndOutcomesBySource().get(
+				autoconfigKey);
+		Iterator<ConditionAndOutcome> iterator = conditionAndOutcomes.iterator();
+		int i = 0;
+		boolean foundConditionalOnClass = false;
+		boolean foundConditionalOnBean = false;
+		while (iterator.hasNext()) {
+			ConditionAndOutcome conditionAndOutcome = iterator.next();
+			if (conditionAndOutcome.getOutcome().getMessage().contains(
+					"@ConditionalOnClass classes found: javax.servlet.Servlet,org.springframework.web.multipart.support.StandardServletMultipartResolver")) {
+				foundConditionalOnClass = true;
+			}
+			if (conditionAndOutcome.getOutcome().getMessage().contains(
+					"@ConditionalOnBean (types: javax.servlet.MultipartConfigElement; SearchStrategy: all) found no beans")) {
+				foundConditionalOnBean = true;
+			}
+			i++;
+		}
+
+		assertThat(i, equalTo(2));
+		assertTrue(foundConditionalOnClass);
+		assertTrue(foundConditionalOnBean);
+
+	}
+
 	@Configurable
 	@Import(WebMvcAutoConfiguration.class)
 	static class Config {
 
 	}
 
+	@Configurable
+	@Import(MultipartAutoConfiguration.class)
+	static class DuplicateConfig {
+
+	}
+
 }

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/orm/jpa/AbstractJpaAutoConfigurationTests.java

@@ -216,4 +216,5 @@ public abstract class AbstractJpaAutoConfigurationTests {
 
 	static class CustomJpaTransactionManager extends JpaTransactionManager {
 	}
+
 }

spring-boot/src/test/java/org/springframework/boot/context/embedded/AbstractEmbeddedServletContainerFactoryTests.java

@@ -18,7 +18,6 @@ package org.springframework.boot.context.embedded;
 
 import java.io.FileWriter;
 import java.io.IOException;
-import java.net.SocketException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.nio.charset.Charset;
@@ -99,7 +98,7 @@ public abstract class AbstractEmbeddedServletContainerFactoryTests {
 		this.container = factory
 				.getEmbeddedServletContainer(exampleServletRegistration());
 		this.container.start();
-		this.thrown.expect(SocketException.class);
+		this.thrown.expect(IOException.class);
 		getResponse("http://localhost:8080/hello");
 	}
 
@@ -110,7 +109,7 @@ public abstract class AbstractEmbeddedServletContainerFactoryTests {
 				.getEmbeddedServletContainer(exampleServletRegistration());
 		this.container.start();
 		this.container.stop();
-		this.thrown.expect(SocketException.class);
+		this.thrown.expect(IOException.class);
 		getResponse("http://localhost:8080/hello");
 	}