Issue ota4j-team#21: Add test for DebuggableException

* Refactored ExceptionTestHelper to provide better/easier to understand
  support for testing DebuggableExceptions.
* Introduces test for DebuggableException
* Renames methods of DebugInformation to be similar to Map interface.

src/main/java/org/opentest4j/AssertionFailedException.java

@@ -16,9 +16,9 @@
 
 package org.opentest4j;
 
+import static org.opentest4j.debug.DebugInformation.builder;
 import static org.opentest4j.debug.DebugInformationDefaultKey.ACTUAL;
 import static org.opentest4j.debug.DebugInformationDefaultKey.EXPECTED;
-import static org.opentest4j.debug.DebugInformation.builder;
 
 import org.opentest4j.debug.DebugInformation;
 import org.opentest4j.debug.ValueDescriptor;
@@ -79,7 +79,7 @@ public AssertionFailedException(DebugInformation debugInformation, Throwable cau
 	 */
 	public AssertionFailedException(String message, Object expected, Object actual) {
 		this(message,
-		      builder().addValue(EXPECTED.getId(), expected).addValue(ACTUAL.getId(), actual).build());
+		      builder().put(EXPECTED.getId(), expected).put(ACTUAL.getId(), actual).build());
 	}
 
 	/**
@@ -94,7 +94,7 @@ public AssertionFailedException(String message, Throwable cause) {
 	 */
 	public AssertionFailedException(String message, Object expected, Object actual, Throwable cause) {
 		this(message,
-		      builder().addValue(EXPECTED.getId(), expected).addValue(ACTUAL.getId(), actual).build(),
+		      builder().put(EXPECTED.getId(), expected).put(ACTUAL.getId(), actual).build(),
 		      cause);
 	}
 
@@ -104,7 +104,7 @@ public AssertionFailedException(String message, Object expected, Object actual,
 	 * @see #getExpected()
 	 */
 	public boolean isExpectedDefined() {
-		return hasDebugInformation() && getDebugInformation().hasValue(EXPECTED.getId());
+		return hasDebugInformation() && getDebugInformation().containsKey(EXPECTED.getId());
 	}
 
 	/**
@@ -113,7 +113,7 @@ public boolean isExpectedDefined() {
 	 * @see #getActual()
 	 */
 	public boolean isActualDefined() {
-		return hasDebugInformation() && getDebugInformation().hasValue(ACTUAL.getId());
+		return hasDebugInformation() && getDebugInformation().containsKey(ACTUAL.getId());
 	}
 
 	/**
@@ -122,7 +122,7 @@ public boolean isActualDefined() {
 	 * @see #isExpectedDefined()
 	 */
 	public ValueDescriptor getExpected() {
-		return isExpectedDefined() ? getDebugInformation().getValue(EXPECTED.getId()) : null;
+		return isExpectedDefined() ? getDebugInformation().get(EXPECTED.getId()) : null;
 	}
 
 	/**
@@ -131,7 +131,7 @@ public ValueDescriptor getExpected() {
 	 * @see #isActualDefined()
 	 */
 	public ValueDescriptor getActual() {
-		return isActualDefined() ? getDebugInformation().getValue(ACTUAL.getId()) : null;
+		return isActualDefined() ? getDebugInformation().get(ACTUAL.getId()) : null;
 	}
 
 }

src/main/java/org/opentest4j/debug/DebugInformation.java

@@ -1,7 +1,7 @@
 
 package org.opentest4j.debug;
 
-import static java.util.Collections.unmodifiableMap;
+import static java.util.Collections.unmodifiableSet;
 
 import java.io.Serializable;
 import java.util.HashMap;
@@ -41,7 +41,7 @@ public class DebugInformation implements Serializable {
 	 * @param values values; must be non-null
 	 */
 	private DebugInformation(Map<String, ValueDescriptor> values) {
-		this.values = unmodifiableMap(values);
+		this.values = new HashMap<String, ValueDescriptor>(values);
 	}
 
 	/**
@@ -58,19 +58,19 @@ public static DebugInformationBuilder builder() {
 	 *
 	 * @param key debug information key
 	 * @return value descriptor or {@code null} iff. there is no debug information for the given key.
-	 * @see #hasValue(String)
+	 * @see #containsKey(String)
 	 */
-	public ValueDescriptor getValue(String key) {
+	public ValueDescriptor get(String key) {
 		return this.values.get(key);
 	}
 
 	/**
 	 * Test if a value descriptor for the given debug information key exists.
 	 *
 	 * @param key debug information key
-	 * @return true iff. {@link #getValue(String)} for the given return will return a value different to {@code null}
+	 * @return true iff. {@link #get(String)} for the given return will return a value different to {@code null}
 	 */
-	public boolean hasValue(String key) {
+	public boolean containsKey(String key) {
 		return this.values.containsKey(key);
 	}
 
@@ -79,8 +79,8 @@ public boolean hasValue(String key) {
 	 *
 	 * @return value ids, non-null
 	 */
-	public Set<String> getValueIds() {
-		return this.values.keySet();
+	public Set<String> keySet() {
+		return unmodifiableSet(this.values.keySet());
 	}
 
 	/**
@@ -103,7 +103,7 @@ private DebugInformationBuilder() {
 		 * @param object object, might be {@code null}
 		 * @return self-reference
 		 */
-		public DebugInformationBuilder addValue(String key, Object object) {
+		public DebugInformationBuilder put(String key, Object object) {
 			this.values.put(key, ValueDescriptor.create(object));
 			return this;
 		}

src/test/java/org/opentest4j/DebuggableExceptionTests.java

@@ -0,0 +1,24 @@
+
+package org.opentest4j;
+
+import static org.opentest4j.ExceptionTestHelper.assertBehavesLikeStandardException;
+
+import org.junit.Test;
+
+/**
+ * Tests {@link DebuggableException}.
+ *
+ * @author Mark Michaelis
+ * @since 1.0
+ */
+public class DebuggableExceptionTests {
+	@Test
+	public void standardConstructorsHaveSameBehaviorAsJavaStandard() throws Exception {
+		assertBehavesLikeStandardException(DebuggableException.class);
+	}
+
+	@Test
+	public void debugInformationConstructorsBehaveAsExpected() throws Exception {
+		ExceptionTestHelper.assertBehavesLikeDebuggableException(DebuggableException.class);
+	}
+}