001 /*
002 * Created on Aug 5, 2010
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
005 * the License. You may obtain a copy of the License at
006 *
007 * http://www.apache.org/licenses/LICENSE-2.0
008 *
009 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
010 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
011 * specific language governing permissions and limitations under the License.
012 *
013 * Copyright @2010-2011 the original author or authors.
014 */
015 package org.fest.assertions.internal;
016
017 import static org.fest.util.Strings.isEmpty;
018
019 import org.fest.assertions.core.AssertionInfo;
020 import org.fest.assertions.error.AssertionErrorFactory;
021 import org.fest.assertions.error.ErrorMessageFactory;
022 import org.fest.assertions.error.ShouldBeEqual;
023 import org.fest.util.Throwables;
024 import org.fest.util.VisibleForTesting;
025
026 /**
027 * Failure actions.
028 *
029 * @author Yvonne Wang
030 * @author Alex Ruiz
031 */
032 public class Failures {
033
034 private static final Failures INSTANCE = new Failures();
035
036 /**
037 * Returns the singleton instance of this class.
038 * @return the singleton instance of this class.
039 */
040 public static Failures instance() {
041 return INSTANCE;
042 }
043
044 /**
045 * flag indicating wether or not we remove elements related to Fest from assertion error stack trace.
046 */
047 private boolean removeFestRelatedElementsFromStackTrace = true;
048
049 /**
050 * Sets wether we remove elements related to Fest from assertion error stack trace.
051 * @param removeFestRelatedElementsFromStackTrace flag
052 */
053 public void setRemoveFestRelatedElementsFromStackTrace(boolean removeFestRelatedElementsFromStackTrace) {
054 this.removeFestRelatedElementsFromStackTrace = removeFestRelatedElementsFromStackTrace;
055 }
056
057 @VisibleForTesting
058 Failures() {}
059
060 /**
061 * Creates a <code>{@link AssertionError}</code> following this pattern:
062 * <ol>
063 * <li>creates a <code>{@link AssertionError}</code> using <code>{@link AssertionInfo#overridingErrorMessage()}</code>
064 * as the error message if such value is not {@code null}, or</li>
065 * <li>uses the given <code>{@link AssertionErrorFactory}</code> to create an <code>{@link AssertionError}</code>,
066 * prepending the value of <code>{@link AssertionInfo#description()}</code> to the error message</li>
067 * </ol>
068 * @param info contains information about the failed assertion.
069 * @param factory knows how to create {@code AssertionError}s.
070 * @return the created <code>{@link AssertionError}</code>.
071 */
072 public AssertionError failure(AssertionInfo info, AssertionErrorFactory factory) {
073 AssertionError error = failureIfErrorMessageIsOverriden(info);
074 if (error != null) return error;
075 return factory.newAssertionError(info.description());
076 }
077
078 /**
079 * Creates a <code>{@link AssertionError}</code> following this pattern:
080 * <ol>
081 * <li>creates a <code>{@link AssertionError}</code> using <code>{@link AssertionInfo#overridingErrorMessage()}</code>
082 * as the error message if such value is not {@code null}, or</li>
083 * <li>uses the given <code>{@link ErrorMessageFactory}</code> to create the detail message of the
084 * <code>{@link AssertionError}</code>, prepending the value of <code>{@link AssertionInfo#description()}</code> to
085 * the error message</li>
086 * </ol>
087 * @param info contains information about the failed assertion.
088 * @param message knows how to create detail messages for {@code AssertionError}s.
089 * @return the created <code>{@link AssertionError}</code>.
090 */
091 public AssertionError failure(AssertionInfo info, ErrorMessageFactory message) {
092 AssertionError error = failureIfErrorMessageIsOverriden(info);
093 if (error != null) return error;
094 AssertionError assertionError = new AssertionError(message.create(info.description()));
095 removeFestRelatedElementsFromStackTraceIfNeeded(assertionError);
096 return assertionError;
097 }
098
099 private AssertionError failureIfErrorMessageIsOverriden(AssertionInfo info) {
100 String overridingErrorMessage = info.overridingErrorMessage();
101 if (!isEmpty(overridingErrorMessage)) return failure(overridingErrorMessage);
102 return null;
103 }
104
105 /**
106 * Creates a <code>{@link AssertionError}</code> using the given {@code String} as message.
107 * <p>
108 * It filters the AssertionError stack trace be default, to have full stack trace use {@link #setRemoveFestRelatedElementsFromStackTrace(boolean)}.
109 * @param message the message of the {@code AssertionError} to create.
110 * @return the created <code>{@link AssertionError}</code>.
111 */
112 public AssertionError failure(String message) {
113 AssertionError assertionError = new AssertionError(message);
114 removeFestRelatedElementsFromStackTraceIfNeeded(assertionError);
115 return assertionError;
116 }
117
118 /**
119 * If is {@link #removeFestRelatedElementsFromStackTrace} is true, it filters the stack trace of the given {@link AssertionError}
120 * by removing stack trace elements related to Fest in order to get a more readable stack trace.
121 * <p>
122 * See example below :
123 * <pre>
124 --------------- stack trace not filtered -----------------
125 org.junit.ComparisonFailure: expected:<'[Ronaldo]'> but was:<'[Messi]'>
126 at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
127 at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
128 at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
129 at java.lang.reflect.Constructor.newInstance(Constructor.java:501)
130 at org.fest.assertions.error.ConstructorInvoker.newInstance(ConstructorInvoker.java:34)
131 at org.fest.assertions.error.ShouldBeEqual.newComparisonFailure(ShouldBeEqual.java:111)
132 at org.fest.assertions.error.ShouldBeEqual.comparisonFailure(ShouldBeEqual.java:103)
133 at org.fest.assertions.error.ShouldBeEqual.newAssertionError(ShouldBeEqual.java:81)
134 at org.fest.assertions.internal.Failures.failure(Failures.java:76)
135 at org.fest.assertions.internal.Objects.assertEqual(Objects.java:116)
136 at org.fest.assertions.api.AbstractAssert.isEqualTo(AbstractAssert.java:74)
137 at examples.StackTraceFilterExample.main(StackTraceFilterExample.java:13)
138
139 --------------- stack trace filtered -----------------
140 org.junit.ComparisonFailure: expected:<'[Ronaldo]'> but was:<'[Messi]'>
141 at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
142 at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
143 at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
144 at examples.StackTraceFilterExample.main(StackTraceFilterExample.java:20)
145 * </pre>
146 *
147 * Method is public because we need to call it from {@link ShouldBeEqual#newAssertionError(org.fest.assertions.description.Description)} that is building a junit ComparisonFailure by reflection.
148 *
149 * @param assertionError the {@code AssertionError} to filter stack trace if option is set.
150 */
151 public void removeFestRelatedElementsFromStackTraceIfNeeded(AssertionError assertionError) {
152 if (removeFestRelatedElementsFromStackTrace) {
153 Throwables.removeFestRelatedElementsFromStackTrace(assertionError);
154 }
155 }
156
157 }