1 files changed, 77 insertions, 0 deletions
diff --git a/hamcrest-core/src/test/java/org/hamcrest/AbstractMatcherTest.java b/hamcrest-core/src/test/java/org/hamcrest/AbstractMatcherTest.java
new file mode 100644
index 0000000..22f823b
--- /dev/null
+++ b/hamcrest-core/src/test/java/org/hamcrest/AbstractMatcherTest.java
@@ -0,0 +1,77 @@
+package org.hamcrest;
+
+import junit.framework.TestCase;
+import org.junit.Assert;
+
+public abstract class AbstractMatcherTest extends TestCase {
+
+  /**
+   * Create an instance of the Matcher so some generic safety-net tests can be run on it.
+   */
+  protected abstract Matcher<?> createMatcher();
+  
+  public static <T> void assertMatches(Matcher<T> matcher, T arg) {
+      assertMatches("Expected match, but mismatched", matcher, arg);
+  }
+
+  public static <T> void assertMatches(String message, Matcher<T> matcher, T arg) {
+    if (!matcher.matches(arg)) {
+      Assert.fail(message + " because: '" + mismatchDescription(matcher, arg) + "'");
+    }
+  }
+
+  public static <T> void assertDoesNotMatch(Matcher<? super T> c, T arg) {
+      assertDoesNotMatch("Unexpected match", c, arg);
+  }
+
+  public static <T> void assertDoesNotMatch(String message, Matcher<? super T> c, T arg) {
+    Assert.assertFalse(message, c.matches(arg));
+  }
+
+  public static void assertDescription(String expected, Matcher<?> matcher) {
+    Description description = new StringDescription();
+    description.appendDescriptionOf(matcher);
+    Assert.assertEquals("Expected description", expected, description.toString().trim());
+  }
+
+  public static <T> void assertMismatchDescription(String expected, Matcher<? super T> matcher, T arg) {
+    Assert.assertFalse("Precondition: Matcher should not match item.", matcher.matches(arg));
+    Assert.assertEquals("Expected mismatch description", expected, mismatchDescription(matcher, arg));
+  }
+  
+  public static void assertNullSafe(Matcher<?> matcher) {
+      try {
+          matcher.matches(null);
+      }
+      catch (Exception e) {
+          Assert.fail("Matcher was not null safe");
+      }
+  }
+
+  public static void assertUnknownTypeSafe(Matcher<?> matcher) {
+      try {
+          matcher.matches(new UnknownType());
+      }
+      catch (Exception e) {
+          Assert.fail("Matcher was not unknown type safe");
+      }
+  }
+
+  public static <T> String mismatchDescription(Matcher<? super T> matcher, T arg) {
+    Description description = new StringDescription();
+    matcher.describeMismatch(arg, description);
+    return description.toString().trim();
+  }
+
+  public void testIsNullSafe() {
+    assertNullSafe(createMatcher());
+  }
+
+  public void testCopesWithUnknownTypes() {
+    assertUnknownTypeSafe(createMatcher());
+  }
+
+  public static class UnknownType {
+  }
+
+}