001package org.junit.runner;
002
003import java.io.Serializable;
004import java.lang.annotation.Annotation;
005import java.util.ArrayList;
006import java.util.Arrays;
007import java.util.Collection;
008import java.util.concurrent.ConcurrentLinkedQueue;
009import java.util.regex.Matcher;
010import 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 */
030public 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     * Create a <code>Description</code> named after <code>testClass</code>
129     *
130     * @param testClass A not null {@link Class} containing tests
131     * @param annotations meta-data about the test, for downstream interpreters
132     * @return a <code>Description</code> of <code>testClass</code>
133     */
134    public static Description createSuiteDescription(Class<?> testClass, Annotation... annotations) {
135        return new Description(testClass, testClass.getName(), annotations);
136    }
137
138    /**
139     * Describes a Runner which runs no tests
140     */
141    public static final Description EMPTY = new Description(null, "No Tests");
142
143    /**
144     * Describes a step in the test-running mechanism that goes so wrong no
145     * other description can be used (for example, an exception thrown from a Runner's
146     * constructor
147     */
148    public static final Description TEST_MECHANISM = new Description(null, "Test mechanism");
149
150    /*
151     * We have to use the f prefix until the next major release to ensure
152     * serialization compatibility. 
153     * See https://github.com/junit-team/junit4/issues/976
154     */
155    private final Collection<Description> fChildren = new ConcurrentLinkedQueue<Description>();
156    private final String fDisplayName;
157    private final Serializable fUniqueId;
158    private final Annotation[] fAnnotations;
159    private volatile /* write-once */ Class<?> fTestClass;
160
161    private Description(Class<?> clazz, String displayName, Annotation... annotations) {
162        this(clazz, displayName, displayName, annotations);
163    }
164
165    private Description(Class<?> testClass, String displayName, Serializable uniqueId, Annotation... annotations) {
166        if ((displayName == null) || (displayName.length() == 0)) {
167            throw new IllegalArgumentException(
168                    "The display name must not be empty.");
169        }
170        if ((uniqueId == null)) {
171            throw new IllegalArgumentException(
172                    "The unique id must not be null.");
173        }
174        this.fTestClass = testClass;
175        this.fDisplayName = displayName;
176        this.fUniqueId = uniqueId;
177        this.fAnnotations = annotations;
178    }
179
180    /**
181     * @return a user-understandable label
182     */
183    public String getDisplayName() {
184        return fDisplayName;
185    }
186
187    /**
188     * Add <code>Description</code> as a child of the receiver.
189     *
190     * @param description the soon-to-be child.
191     */
192    public void addChild(Description description) {
193        fChildren.add(description);
194    }
195
196    /**
197     * Gets the copy of the children of this {@code Description}.
198     * Returns an empty list if there are no children.
199     */
200    public ArrayList<Description> getChildren() {
201        return new ArrayList<Description>(fChildren);
202    }
203
204    /**
205     * @return <code>true</code> if the receiver is a suite
206     */
207    public boolean isSuite() {
208        return !isTest();
209    }
210
211    /**
212     * @return <code>true</code> if the receiver is an atomic test
213     */
214    public boolean isTest() {
215        return fChildren.isEmpty();
216    }
217
218    /**
219     * @return the total number of atomic tests in the receiver
220     */
221    public int testCount() {
222        if (isTest()) {
223            return 1;
224        }
225        int result = 0;
226        for (Description child : fChildren) {
227            result += child.testCount();
228        }
229        return result;
230    }
231
232    @Override
233    public int hashCode() {
234        return fUniqueId.hashCode();
235    }
236
237    @Override
238    public boolean equals(Object obj) {
239        if (!(obj instanceof Description)) {
240            return false;
241        }
242        Description d = (Description) obj;
243        return fUniqueId.equals(d.fUniqueId);
244    }
245
246    @Override
247    public String toString() {
248        return getDisplayName();
249    }
250
251    /**
252     * @return true if this is a description of a Runner that runs no tests
253     */
254    public boolean isEmpty() {
255        return equals(EMPTY);
256    }
257
258    /**
259     * @return a copy of this description, with no children (on the assumption that some of the
260     *         children will be added back)
261     */
262    public Description childlessCopy() {
263        return new Description(fTestClass, fDisplayName, fAnnotations);
264    }
265
266    /**
267     * @return the annotation of type annotationType that is attached to this description node,
268     *         or null if none exists
269     */
270    public <T extends Annotation> T getAnnotation(Class<T> annotationType) {
271        for (Annotation each : fAnnotations) {
272            if (each.annotationType().equals(annotationType)) {
273                return annotationType.cast(each);
274            }
275        }
276        return null;
277    }
278
279    /**
280     * @return all of the annotations attached to this description node
281     */
282    public Collection<Annotation> getAnnotations() {
283        return Arrays.asList(fAnnotations);
284    }
285
286    /**
287     * @return If this describes a method invocation,
288     *         the class of the test instance.
289     */
290    public Class<?> getTestClass() {
291        if (fTestClass != null) {
292            return fTestClass;
293        }
294        String name = getClassName();
295        if (name == null) {
296            return null;
297        }
298        try {
299            fTestClass = Class.forName(name, false, getClass().getClassLoader());
300            return fTestClass;
301        } catch (ClassNotFoundException e) {
302            return null;
303        }
304    }
305
306    /**
307     * @return If this describes a method invocation,
308     *         the name of the class of the test instance
309     */
310    public String getClassName() {
311        return fTestClass != null ? fTestClass.getName() : methodAndClassNamePatternGroupOrDefault(2, toString());
312    }
313
314    /**
315     * @return If this describes a method invocation,
316     *         the name of the method (or null if not)
317     */
318    public String getMethodName() {
319        return methodAndClassNamePatternGroupOrDefault(1, null);
320    }
321
322    private String methodAndClassNamePatternGroupOrDefault(int group,
323            String defaultString) {
324        Matcher matcher = METHOD_AND_CLASS_NAME_PATTERN.matcher(toString());
325        return matcher.matches() ? matcher.group(group) : defaultString;
326    }
327}