001    package org.junit.runner;
002    
003    import java.io.Serializable;
004    import java.lang.annotation.Annotation;
005    import java.util.ArrayList;
006    import java.util.Arrays;
007    import java.util.Collection;
008    import java.util.concurrent.ConcurrentLinkedQueue;
009    import java.util.regex.Matcher;
010    import java.util.regex.Pattern;
011    
012    /**
013     * A <code>Description</code> describes a test which is to be run or has been run. <code>Descriptions</code>
014     * can be atomic (a single test) or compound (containing children tests). <code>Descriptions</code> are used
015     * to provide feedback about the tests that are about to run (for example, the tree view
016     * visible in many IDEs) or tests that have been run (for example, the failures view).
017     * <p>
018     * <code>Descriptions</code> are implemented as a single class rather than a Composite because
019     * they are entirely informational. They contain no logic aside from counting their tests.
020     * <p>
021     * In the past, we used the raw {@link junit.framework.TestCase}s and {@link junit.framework.TestSuite}s
022     * to display the tree of tests. This was no longer viable in JUnit 4 because atomic tests no longer have
023     * a superclass below {@link Object}. We needed a way to pass a class and name together. Description
024     * emerged from this.
025     *
026     * @see org.junit.runner.Request
027     * @see org.junit.runner.Runner
028     * @since 4.0
029     */
030    public class Description implements Serializable {
031        private static final long serialVersionUID = 1L;
032    
033        private static final Pattern METHOD_AND_CLASS_NAME_PATTERN = Pattern
034                .compile("([\\s\\S]*)\\((.*)\\)");
035    
036        /**
037         * Create a <code>Description</code> named <code>name</code>.
038         * Generally, you will add children to this <code>Description</code>.
039         *
040         * @param name the name of the <code>Description</code>
041         * @param annotations meta-data about the test, for downstream interpreters
042         * @return a <code>Description</code> named <code>name</code>
043         */
044        public static Description createSuiteDescription(String name, Annotation... annotations) {
045            return new Description(null, name, annotations);
046        }
047    
048        /**
049         * Create a <code>Description</code> named <code>name</code>.
050         * Generally, you will add children to this <code>Description</code>.
051         *
052         * @param name the name of the <code>Description</code>
053         * @param uniqueId an arbitrary object used to define uniqueness (in {@link #equals(Object)}
054         * @param annotations meta-data about the test, for downstream interpreters
055         * @return a <code>Description</code> named <code>name</code>
056         */
057        public static Description createSuiteDescription(String name, Serializable uniqueId, Annotation... annotations) {
058            return new Description(null, name, uniqueId, annotations);
059        }
060    
061        /**
062         * Create a <code>Description</code> of a single test named <code>name</code> in the 'class' named
063         * <code>className</code>. Generally, this will be a leaf <code>Description</code>. This method is a better choice
064         * than {@link #createTestDescription(Class, String, Annotation...)} for test runners whose test cases are not
065         * defined in an actual Java <code>Class</code>.
066         *
067         * @param className the class name of the test
068         * @param name the name of the test (a method name for test annotated with {@link org.junit.Test})
069         * @param annotations meta-data about the test, for downstream interpreters
070         * @return a <code>Description</code> named <code>name</code>
071         */
072        public static Description createTestDescription(String className, String name, Annotation... annotations) {
073            return new Description(null, formatDisplayName(name, className), annotations);
074        }
075    
076        /**
077         * Create a <code>Description</code> of a single test named <code>name</code> in the class <code>clazz</code>.
078         * Generally, this will be a leaf <code>Description</code>.
079         *
080         * @param clazz the class of the test
081         * @param name the name of the test (a method name for test annotated with {@link org.junit.Test})
082         * @param annotations meta-data about the test, for downstream interpreters
083         * @return a <code>Description</code> named <code>name</code>
084         */
085        public static Description createTestDescription(Class<?> clazz, String name, Annotation... annotations) {
086            return new Description(clazz, formatDisplayName(name, clazz.getName()), annotations);
087        }
088    
089        /**
090         * Create a <code>Description</code> of a single test named <code>name</code> in the class <code>clazz</code>.
091         * Generally, this will be a leaf <code>Description</code>.
092         * (This remains for binary compatibility with clients of JUnit 4.3)
093         *
094         * @param clazz the class of the test
095         * @param name the name of the test (a method name for test annotated with {@link org.junit.Test})
096         * @return a <code>Description</code> named <code>name</code>
097         */
098        public static Description createTestDescription(Class<?> clazz, String name) {
099            return new Description(clazz, formatDisplayName(name, clazz.getName()));
100        }
101    
102        /**
103         * Create a <code>Description</code> of a single test named <code>name</code> in the class <code>clazz</code>.
104         * Generally, this will be a leaf <code>Description</code>.
105         *
106         * @param name the name of the test (a method name for test annotated with {@link org.junit.Test})
107         * @return a <code>Description</code> named <code>name</code>
108         */
109        public static Description createTestDescription(String className, String name, Serializable uniqueId) {
110            return new Description(null, formatDisplayName(name, className), uniqueId);
111        }
112    
113        private static String formatDisplayName(String name, String className) {
114            return String.format("%s(%s)", name, className);
115        }
116    
117        /**
118         * Create a <code>Description</code> named after <code>testClass</code>
119         *
120         * @param testClass A {@link Class} containing tests
121         * @return a <code>Description</code> of <code>testClass</code>
122         */
123        public static Description createSuiteDescription(Class<?> testClass) {
124            return new Description(testClass, testClass.getName(), testClass.getAnnotations());
125        }
126    
127        /**
128         * Describes a Runner which runs no tests
129         */
130        public static final Description EMPTY = new Description(null, "No Tests");
131    
132        /**
133         * Describes a step in the test-running mechanism that goes so wrong no
134         * other description can be used (for example, an exception thrown from a Runner's
135         * constructor
136         */
137        public static final Description TEST_MECHANISM = new Description(null, "Test mechanism");
138    
139        private final Collection<Description> children = new ConcurrentLinkedQueue<Description>();
140        private final String displayName;
141        private final Serializable uniqueId;
142        private final Annotation[] annotations;
143        private volatile /* write-once */ Class<?> testClass;
144    
145        private Description(Class<?> clazz, String displayName, Annotation... annotations) {
146            this(clazz, displayName, displayName, annotations);
147        }
148    
149        private Description(Class<?> testClass, String displayName, Serializable uniqueId, Annotation... annotations) {
150            if ((displayName == null) || (displayName.length() == 0)) {
151                throw new IllegalArgumentException(
152                        "The display name must not be empty.");
153            }
154            if ((uniqueId == null)) {
155                throw new IllegalArgumentException(
156                        "The unique id must not be null.");
157            }
158            this.testClass = testClass;
159            this.displayName = displayName;
160            this.uniqueId = uniqueId;
161            this.annotations = annotations;
162        }
163    
164        /**
165         * @return a user-understandable label
166         */
167        public String getDisplayName() {
168            return displayName;
169        }
170    
171        /**
172         * Add <code>Description</code> as a child of the receiver.
173         *
174         * @param description the soon-to-be child.
175         */
176        public void addChild(Description description) {
177            children.add(description);
178        }
179    
180        /**
181         * Gets the copy of the children of this {@code Description}.
182         * Returns an empty list if there are no children.
183         */
184        public ArrayList<Description> getChildren() {
185            return new ArrayList<Description>(children);
186        }
187    
188        /**
189         * @return <code>true</code> if the receiver is a suite
190         */
191        public boolean isSuite() {
192            return !isTest();
193        }
194    
195        /**
196         * @return <code>true</code> if the receiver is an atomic test
197         */
198        public boolean isTest() {
199            return children.isEmpty();
200        }
201    
202        /**
203         * @return the total number of atomic tests in the receiver
204         */
205        public int testCount() {
206            if (isTest()) {
207                return 1;
208            }
209            int result = 0;
210            for (Description child : children) {
211                result += child.testCount();
212            }
213            return result;
214        }
215    
216        @Override
217        public int hashCode() {
218            return uniqueId.hashCode();
219        }
220    
221        @Override
222        public boolean equals(Object obj) {
223            if (!(obj instanceof Description)) {
224                return false;
225            }
226            Description d = (Description) obj;
227            return uniqueId.equals(d.uniqueId);
228        }
229    
230        @Override
231        public String toString() {
232            return getDisplayName();
233        }
234    
235        /**
236         * @return true if this is a description of a Runner that runs no tests
237         */
238        public boolean isEmpty() {
239            return equals(EMPTY);
240        }
241    
242        /**
243         * @return a copy of this description, with no children (on the assumption that some of the
244         *         children will be added back)
245         */
246        public Description childlessCopy() {
247            return new Description(testClass, displayName, annotations);
248        }
249    
250        /**
251         * @return the annotation of type annotationType that is attached to this description node,
252         *         or null if none exists
253         */
254        public <T extends Annotation> T getAnnotation(Class<T> annotationType) {
255            for (Annotation each : annotations) {
256                if (each.annotationType().equals(annotationType)) {
257                    return annotationType.cast(each);
258                }
259            }
260            return null;
261        }
262    
263        /**
264         * @return all of the annotations attached to this description node
265         */
266        public Collection<Annotation> getAnnotations() {
267            return Arrays.asList(annotations);
268        }
269    
270        /**
271         * @return If this describes a method invocation,
272         *         the class of the test instance.
273         */
274        public Class<?> getTestClass() {
275            if (testClass != null) {
276                return testClass;
277            }
278            String name = getClassName();
279            if (name == null) {
280                return null;
281            }
282            try {
283                testClass = Class.forName(name, false, getClass().getClassLoader());
284                return testClass;
285            } catch (ClassNotFoundException e) {
286                return null;
287            }
288        }
289    
290        /**
291         * @return If this describes a method invocation,
292         *         the name of the class of the test instance
293         */
294        public String getClassName() {
295            return testClass != null ? testClass.getName() : methodAndClassNamePatternGroupOrDefault(2, toString());
296        }
297    
298        /**
299         * @return If this describes a method invocation,
300         *         the name of the method (or null if not)
301         */
302        public String getMethodName() {
303            return methodAndClassNamePatternGroupOrDefault(1, null);
304        }
305    
306        private String methodAndClassNamePatternGroupOrDefault(int group,
307                String defaultString) {
308            Matcher matcher = METHOD_AND_CLASS_NAME_PATTERN.matcher(toString());
309            return matcher.matches() ? matcher.group(group) : defaultString;
310        }
311    }