AsyncRetryExecutorManyFailuresTest.java

package com.nurkiewicz.asyncretry;

import org.assertj.core.api.Assertions;
import org.mockito.InOrder;
import org.testng.annotations.Test;

import java.math.BigDecimal;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;

import static com.nurkiewicz.asyncretry.backoff.FixedIntervalBackoff.DEFAULT_PERIOD_MILLIS;
import static org.assertj.core.api.Assertions.assertThat;
import static org.mockito.BDDMockito.given;
import static org.mockito.Mockito.eq;
import static org.mockito.Mockito.inOrder;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;

/**
 * @author Tomasz Nurkiewicz
 * @since 7/16/13, 10:51 PM
 */
public class AsyncRetryExecutorManyFailuresTest extends AbstractBaseTestCase {

	@Test
	public void shouldRethrowIfFirstFewExecutionsThrow() throws Exception {
		//given
		final RetryExecutor executor = new AsyncRetryExecutor(schedulerMock).withMaxRetries(2);
		given(serviceMock.sometimesFails()).willThrow(new IllegalStateException(DON_T_PANIC));

		//when
		final CompletableFuture<String> future = executor.getWithRetry(serviceMock::sometimesFails);

		//then
		assertThat(future.isCompletedExceptionally()).isTrue();
		try {
			future.get();
			Assertions.failBecauseExceptionWasNotThrown(IllegalStateException.class);
		} catch (ExecutionException e) {
			final Throwable actualCause = e.getCause();
			assertThat(actualCause).isInstanceOf(IllegalStateException.class);
			assertThat(actualCause.getMessage()).isEqualToIgnoringCase(DON_T_PANIC);
		}
	}

	@Test
	public void shouldRetryAfterManyExceptionsAndReturnValue() throws Exception {
		//given
		final RetryExecutor executor = new AsyncRetryExecutor(schedulerMock);
		given(serviceMock.sometimesFails()).
				willThrow(IllegalStateException.class, IllegalStateException.class, IllegalStateException.class).
				willReturn("Foo");

		//when
		final CompletableFuture<String> future = executor.getWithRetry(serviceMock::sometimesFails);

		//then
		assertThat(future.get()).isEqualTo("Foo");
	}

	@Test
	public void shouldSucceedWhenTheSameNumberOfRetriesAsFailuresAllowed() throws Exception {
		//given
		final RetryExecutor executor = new AsyncRetryExecutor(schedulerMock).withMaxRetries(3);
		given(serviceMock.sometimesFails()).
				willThrow(IllegalStateException.class, IllegalStateException.class, IllegalStateException.class).
				willReturn("Foo");

		//when
		final CompletableFuture<String> future = executor.getWithRetry(serviceMock::sometimesFails);

		//then
		assertThat(future.get()).isEqualTo("Foo");
	}

	@Test
	public void shouldRetryManyTimesIfFirstExecutionsThrowException() throws Exception {
		//given
		final RetryExecutor executor = new AsyncRetryExecutor(schedulerMock);
		given(serviceMock.sometimesFails()).
				willThrow(IllegalStateException.class, IllegalStateException.class, IllegalStateException.class).
				willReturn("Foo");

		//when
		executor.getWithRetry(serviceMock::sometimesFails);

		//then
		verify(serviceMock, times(4)).sometimesFails();
	}

	@Test
	public void shouldScheduleRetryWithDefaultDelay() throws Exception {
		//given
		final RetryExecutor executor = new AsyncRetryExecutor(schedulerMock);
		given(serviceMock.sometimesFails()).
				willThrow(IllegalStateException.class, IllegalStateException.class, IllegalStateException.class).
				willReturn("Foo");

		//when
		executor.getWithRetry(serviceMock::sometimesFails);

		//then
		final InOrder inOrder = inOrder(schedulerMock);
		inOrder.verify(schedulerMock).schedule(notNullRunnable(), eq(0L), millis());
		inOrder.verify(schedulerMock, times(3)).schedule(notNullRunnable(), eq(DEFAULT_PERIOD_MILLIS), millis());
		inOrder.verifyNoMoreInteractions();
	}

	@Test
	public void shouldPassCorrectRetryCountToEachInvocationInContext() throws Exception {
		//given
		final RetryExecutor executor = new AsyncRetryExecutor(schedulerMock);
		given(serviceMock.calculateSum(0)).willThrow(IllegalStateException.class);
		given(serviceMock.calculateSum(1)).willThrow(IllegalStateException.class);
		given(serviceMock.calculateSum(2)).willThrow(IllegalStateException.class);
		given(serviceMock.calculateSum(3)).willReturn(BigDecimal.ONE);

		//when
		executor.getWithRetry(ctx -> serviceMock.calculateSum(ctx.getRetryCount()));

		//then
		final InOrder order = inOrder(serviceMock);
		order.verify(serviceMock).calculateSum(0);
		order.verify(serviceMock).calculateSum(1);
		order.verify(serviceMock).calculateSum(2);
		order.verify(serviceMock).calculateSum(3);
		order.verifyNoMoreInteractions();
	}

}