add ExceptionCauseMatcher to sonar-testing-harness

diff --git a/sonar-testing-harness/src/main/java/org/sonar/test/ExceptionCauseMatcher.java b/sonar-testing-harness/src/main/java/org/sonar/test/ExceptionCauseMatcher.java
new file mode 100644 (file)
index 0000000..9eaf1d6
--- /dev/null
+++ b/sonar-testing-harness/src/main/java/org/sonar/test/ExceptionCauseMatcher.java
@@ -0,0 +1,83 @@
+/*
+ * SonarQube, open source software quality management tool.
+ * Copyright (C) 2008-2014 SonarSource
+ * mailto:contact AT sonarsource DOT com
+ *
+ * SonarQube is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * SonarQube is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+package org.sonar.test;
+
+import java.util.Objects;
+import javax.annotation.CheckForNull;
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.Immutable;
+import org.hamcrest.Description;
+import org.hamcrest.Matcher;
+import org.hamcrest.TypeSafeMatcher;
+
+/**
+ * Matchers designed to be used as an argument of {@link org.junit.rules.ExpectedException#expectCause(Matcher)} such as:
+ *
+ * <pre>
+ * expectedException.expect(VisitException.class);
+ * expectedException.expectCause(hasType(IllegalArgumentException.class).andMessage("file and otherFile Components can not be the same"));
+ * </pre>
+ *
+ * Class strongly inspired from {@code CauseMatcher} class from {@code http://blog.codeleak.pl/2014/03/junit-expectedexception-rule-beyond.html}
+ */
+@Immutable
+public class ExceptionCauseMatcher extends TypeSafeMatcher<Throwable> {
+  private static final String EXPECT_NO_MESSAGE_CONSTANT = "RQXG8QTUCXOT7HZ3APPKBKUE5";
+
+  private final Class<? extends Throwable> type;
+  @CheckForNull
+  private final String expectedMessage;
+
+  private ExceptionCauseMatcher(Class<? extends Throwable> type, @Nullable String expectedMessage) {
+    this.type = type;
+    this.expectedMessage = expectedMessage;
+  }
+
+  public static ExceptionCauseMatcher hasType(Class<? extends Throwable> type) {
+    return new ExceptionCauseMatcher(type, null);
+  }
+
+  public ExceptionCauseMatcher andMessage(String expectedMessage) {
+    return new ExceptionCauseMatcher(type, Objects.requireNonNull(expectedMessage));
+  }
+
+  public ExceptionCauseMatcher andNoMessage() {
+    return new ExceptionCauseMatcher(type, EXPECT_NO_MESSAGE_CONSTANT);
+  }
+
+  @Override
+  protected boolean matchesSafely(Throwable item) {
+    return item.getClass().isAssignableFrom(type)
+      && (expectedMessage == null || EXPECT_NO_MESSAGE_CONSTANT.equals(expectedMessage) ? item.getMessage() == null : item.getMessage().contains(expectedMessage));
+  }
+
+  @Override
+  public void describeTo(Description description) {
+    description.appendText("of type ")
+      .appendValue(type);
+    if (EXPECT_NO_MESSAGE_CONSTANT.equals(expectedMessage)) {
+      description.appendText(" and no message");
+    } else if (expectedMessage != null) {
+      description.appendText(" and message ")
+        .appendValue(expectedMessage);
+    }
+    description.appendText(" but");
+  }
+}