Simplified test cases using AssertThrows(...).

h2/src/test/org/h2/test/utils/AssertThrows.java

+/*
+ * Copyright 2004-2011 H2 Group. Multiple-Licensed under the H2 License,
+ * Version 1.0, and under the Eclipse Public License, Version 1.0
+ * (http://h2database.com/html/license.html).
+ * Initial Developer: H2 Group
+ */
+package org.h2.test.utils;
+
+/**
+ * Helper class to for negative testing. Usage:
+ * <pre>
+ * new AssertThrows() { public void test() {
+ *     Integer.parseInt("not a number");
+ * }};
+ * </pre>
+ */
+public abstract class AssertThrows {
+
+    public AssertThrows(final Class<? extends Exception> expectedExceptionClass) {
+        this(new Thread.UncaughtExceptionHandler() {
+            public void uncaughtException(Thread t, Throwable e) {
+                if (!expectedExceptionClass.isAssignableFrom(e.getClass())) {
+                    AssertionError ae = new AssertionError(
+                            "Expected an exception of type\n" +
+                            expectedExceptionClass.getSimpleName() +
+                            " to be thrown, but the method under test threw an exception of type\n" +
+                            e.getClass().getSimpleName() +
+                            " (see in the 'Caused by' for the exception tha was thrown)");
+                    ae.initCause(e);
+                    throw ae;
+                }
+            }
+        }, "Expected an exception of type " +
+                expectedExceptionClass.getSimpleName() +
+                ", but the test was successful");
+    }
+
+    public AssertThrows() {
+        this(new Thread.UncaughtExceptionHandler() {
+            public void uncaughtException(Thread t, Throwable e) {
+                // all exceptions are fine
+            }
+        }, "Expected an exception to be thrown, but the test was successful");
+    }
+
+    private AssertThrows(Thread.UncaughtExceptionHandler handler, String expected) {
+        try {
+            test();
+            throw new AssertionError(expected);
+        } catch (Exception e) {
+            handler.uncaughtException(null, e);
+        }
+    }
+
+    public abstract void test() throws Exception;
+
+}