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