/*
 * Copyright 2015-2019 the original author or authors.
 *
 * All rights reserved. This program and the accompanying materials are
 * made available under the terms of the Eclipse Public License v2.0 which
 * accompanies this distribution and is available at
 *
 * http://www.eclipse.org/legal/epl-v20.html
 */

package org.junit.jupiter.api;

import static org.junit.jupiter.api.AssertionUtils.buildPrefix;
import static org.junit.jupiter.api.AssertionUtils.format;
import static org.junit.jupiter.api.AssertionUtils.getCanonicalName;
import static org.junit.jupiter.api.AssertionUtils.nullSafeGet;

import java.util.function.Supplier;

import org.junit.jupiter.api.function.Executable;
import org.junit.platform.commons.util.BlacklistedExceptions;
import org.opentest4j.AssertionFailedError;

AssertThrows is a collection of utility methods that support asserting an exception of an expected type is thrown.
Since:5.0
/** * {@code AssertThrows} is a collection of utility methods that support asserting * an exception of an expected type is thrown. * * @since 5.0 */
class AssertThrows { private AssertThrows() { /* no-op */ } static <T extends Throwable> T assertThrows(Class<T> expectedType, Executable executable) { return assertThrows(expectedType, executable, (Object) null); } static <T extends Throwable> T assertThrows(Class<T> expectedType, Executable executable, String message) { return assertThrows(expectedType, executable, (Object) message); } static <T extends Throwable> T assertThrows(Class<T> expectedType, Executable executable, Supplier<String> messageSupplier) { return assertThrows(expectedType, executable, (Object) messageSupplier); } @SuppressWarnings("unchecked") private static <T extends Throwable> T assertThrows(Class<T> expectedType, Executable executable, Object messageOrSupplier) { try { executable.execute(); } catch (Throwable actualException) { if (expectedType.isInstance(actualException)) { return (T) actualException; } else { BlacklistedExceptions.rethrowIfBlacklisted(actualException); String message = buildPrefix(nullSafeGet(messageOrSupplier)) + format(expectedType, actualException.getClass(), "Unexpected exception type thrown"); throw new AssertionFailedError(message, actualException); } } String message = buildPrefix(nullSafeGet(messageOrSupplier)) + String.format("Expected %s to be thrown, but nothing was thrown.", getCanonicalName(expectedType)); throw new AssertionFailedError(message); } }