1 files changed, 242 insertions, 0 deletions
diff --git a/src/main/java/org/junit/runner/Description.java b/src/main/java/org/junit/runner/Description.java
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+++ b/src/main/java/org/junit/runner/Description.java
@@ -0,0 +1,242 @@
+package org.junit.runner;
+
+import java.io.Serializable;
+import java.lang.annotation.Annotation;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * <p>A <code>Description</code> describes a test which is to be run or has been run. <code>Descriptions</code> 
+ * can be atomic (a single test) or compound (containing children tests). <code>Descriptions</code> are used
+ * to provide feedback about the tests that are about to run (for example, the tree view
+ * visible in many IDEs) or tests that have been run (for example, the failures view).</p>
+ * 
+ * <p><code>Descriptions</code> are implemented as a single class rather than a Composite because
+ * they are entirely informational. They contain no logic aside from counting their tests.</p>
+ * 
+ * <p>In the past, we used the raw {@link junit.framework.TestCase}s and {@link junit.framework.TestSuite}s
+ * to display the tree of tests. This was no longer viable in JUnit 4 because atomic tests no longer have 
+ * a superclass below {@link Object}. We needed a way to pass a class and name together. Description 
+ * emerged from this.</p>
+ * 
+ * @see org.junit.runner.Request
+ * @see org.junit.runner.Runner
+ */
+public class Description implements Serializable {
+	private static final long serialVersionUID = 1L;
+
+	/**
+	 * Create a <code>Description</code> named <code>name</code>.
+	 * Generally, you will add children to this <code>Description</code>.
+	 * @param name the name of the <code>Description</code> 
+	 * @param annotations 
+	 * @return a <code>Description</code> named <code>name</code>
+	 */
+	public static Description createSuiteDescription(String name, Annotation... annotations) {
+		if (name.length() == 0)
+			throw new IllegalArgumentException("name must have non-zero length");
+		return new Description(name, annotations);
+	}
+
+	/**
+	 * Create a <code>Description</code> of a single test named <code>name</code> in the class <code>clazz</code>.
+	 * Generally, this will be a leaf <code>Description</code>.
+	 * @param clazz the class of the test
+	 * @param name the name of the test (a method name for test annotated with {@link org.junit.Test})
+	 * @param annotations meta-data about the test, for downstream interpreters
+	 * @return a <code>Description</code> named <code>name</code>
+	 */
+	public static Description createTestDescription(Class<?> clazz, String name, Annotation... annotations) {
+		return new Description(String.format("%s(%s)", name, clazz.getName()), annotations);
+	}
+
+	/**
+	 * Create a <code>Description</code> of a single test named <code>name</code> in the class <code>clazz</code>.
+	 * Generally, this will be a leaf <code>Description</code>.  
+	 * (This remains for binary compatibility with clients of JUnit 4.3)
+	 * @param clazz the class of the test
+	 * @param name the name of the test (a method name for test annotated with {@link org.junit.Test})
+	 * @return a <code>Description</code> named <code>name</code>
+	 */
+	public static Description createTestDescription(Class<?> clazz, String name) {
+		return createTestDescription(clazz, name, new Annotation[0]);
+	}
+
+	/**
+	 * Create a <code>Description</code> named after <code>testClass</code>
+	 * @param testClass A {@link Class} containing tests 
+	 * @return a <code>Description</code> of <code>testClass</code>
+	 */
+	public static Description createSuiteDescription(Class<?> testClass) {
+		return new Description(testClass.getName(), testClass.getAnnotations());
+	}
+	
+	/**
+	 * Describes a Runner which runs no tests
+	 */
+	public static final Description EMPTY= new Description("No Tests");
+	
+	/**
+	 * Describes a step in the test-running mechanism that goes so wrong no
+	 * other description can be used (for example, an exception thrown from a Runner's
+	 * constructor
+	 */
+	public static final Description TEST_MECHANISM= new Description("Test mechanism");
+	
+	private final ArrayList<Description> fChildren= new ArrayList<Description>();
+	private final String fDisplayName;
+	
+	private final Annotation[] fAnnotations;
+	
+	private Description(final String displayName, Annotation... annotations) {
+		fDisplayName= displayName;
+		fAnnotations= annotations;
+	}
+
+	/**
+	 * @return a user-understandable label
+	 */
+	public String getDisplayName() {
+		return fDisplayName;
+	}
+
+	/**
+	 * Add <code>Description</code> as a child of the receiver.
+	 * @param description the soon-to-be child.
+	 */
+	public void addChild(Description description) {
+		getChildren().add(description);
+	}
+
+	/**
+	 * @return the receiver's children, if any
+	 */
+	public ArrayList<Description> getChildren() {
+		return fChildren;
+	}
+
+	/**
+	 * @return <code>true</code> if the receiver is a suite
+	 */
+	public boolean isSuite() {
+		return !isTest();
+	}
+
+	/**
+	 * @return <code>true</code> if the receiver is an atomic test
+	 */
+	public boolean isTest() {
+		return getChildren().isEmpty();
+	}
+
+	/**
+	 * @return the total number of atomic tests in the receiver
+	 */
+	public int testCount() {
+		if (isTest())
+			return 1;
+		int result= 0;
+		for (Description child : getChildren())
+			result+= child.testCount();
+		return result;
+	}
+
+	@Override
+	public int hashCode() {
+		return getDisplayName().hashCode();
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (!(obj instanceof Description))
+			return false;
+		Description d = (Description) obj;
+		return getDisplayName().equals(d.getDisplayName());
+	}
+	
+	@Override
+	public String toString() {
+		return getDisplayName();
+	}
+
+	/**
+	 * @return true if this is a description of a Runner that runs no tests
+	 */
+	public boolean isEmpty() {
+		return equals(EMPTY);
+	}
+
+	/**
+	 * @return a copy of this description, with no children (on the assumption that some of the
+	 * children will be added back)
+	 */
+	public Description childlessCopy() {
+		return new Description(fDisplayName, fAnnotations);
+	}
+
+	/**
+	 * @return the annotation of type annotationType that is attached to this description node, 
+	 * or null if none exists
+	 */
+	public <T extends Annotation> T getAnnotation(Class<T> annotationType) {
+		for (Annotation each : fAnnotations)
+			if (each.annotationType().equals(annotationType))
+				return annotationType.cast(each);
+		return null;
+	}
+
+	/**
+	 * @return all of the annotations attached to this description node
+	 */
+	public Collection<Annotation> getAnnotations() {
+		return Arrays.asList(fAnnotations);
+	}
+
+	/**
+	 * @return If this describes a method invocation, 
+	 * the class of the test instance.
+	 */
+	public Class<?> getTestClass() {
+		String name= getClassName();
+		if (name == null)
+			return null;
+		try {
+			return Class.forName(name);
+		} catch (ClassNotFoundException e) {
+			return null;
+		}
+	}
+
+	/**
+	 * @return If this describes a method invocation, 
+	 * the name of the class of the test instance
+	 */
+	public String getClassName() {
+		Matcher matcher= methodStringMatcher();
+		return matcher.matches()
+			? matcher.group(2)
+			: toString();
+	}
+	
+	/**
+	 * @return If this describes a method invocation, 
+	 * the name of the method (or null if not)
+	 */
+	public String getMethodName() {
+		return parseMethod();
+	}
+
+	private String parseMethod() {
+		Matcher matcher= methodStringMatcher();
+		if (matcher.matches())
+			return matcher.group(1);
+		return null;
+	}
+
+	private Matcher methodStringMatcher() {
+		return Pattern.compile("(.*)\\((.*)\\)").matcher(toString());
+	}
+}
+\ No newline at end of file