EverrestServletTest.java

/*******************************************************************************
 * Copyright (c) 2012-2016 Codenvy, S.A.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Codenvy, S.A. - initial API and implementation
 *******************************************************************************/
package org.everrest.core.servlet;

import org.everrest.core.UnhandledException;
import org.everrest.core.impl.ContainerResponse;
import org.everrest.core.impl.EnvironmentContext;
import org.everrest.core.impl.EverrestProcessor;
import org.everrest.core.tools.ErrorPages;
import org.everrest.core.tools.WebApplicationDeclaredRoles;
import org.hamcrest.BaseMatcher;
import org.hamcrest.Description;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;
import org.mockito.ArgumentCaptor;

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

import static java.util.Collections.emptyEnumeration;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertSame;
import static org.mockito.Matchers.isA;
import static org.mockito.Mockito.doThrow;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

public class EverrestServletTest {
    @Rule public ExpectedException thrown = ExpectedException.none();

    private HttpServletRequest  request;
    private HttpServletResponse response;
    private ServletConfig       servletConfig;
    private ServletContext      servletContext;
    private EverrestProcessor   everrestProcessor;

    private EverrestServlet everrestServlet;

    @Before
    public void setUp() throws Exception {
        request = mock(HttpServletRequest.class);
        response = mock(HttpServletResponse.class);
        servletConfig = mock(ServletConfig.class);
        servletContext = mock(ServletContext.class);
        everrestProcessor = mock(EverrestProcessor.class);

        when(servletConfig.getServletContext()).thenReturn(servletContext);
        when(servletContext.getAttribute(EverrestProcessor.class.getName())).thenReturn(everrestProcessor);

        when(request.getHeaderNames()).thenReturn(emptyEnumeration());

        everrestServlet = new EverrestServlet();
        everrestServlet.init(servletConfig);
    }

    @Test
    public void setsUpEnvironmentContext() throws Exception {
        everrestServlet.service(request, response);

        ArgumentCaptor<EnvironmentContext> envCaptor = ArgumentCaptor.forClass(EnvironmentContext.class);
        verify(everrestProcessor).process(isA(ServletContainerRequest.class), isA(ContainerResponse.class), envCaptor.capture());
        EnvironmentContext env = envCaptor.getValue();

        assertSame(request, env.get(HttpServletRequest.class));
        assertSame(response, env.get(HttpServletResponse.class));
        assertSame(servletConfig, env.get(ServletConfig.class));
        assertSame(servletContext, env.get(ServletContext.class));
        assertNotNull(env.get(WebApplicationDeclaredRoles.class));
        assertNotNull(env.get(ErrorPages.class));
    }

    @Test
    public void rethrowsIOExceptionThatThrownByEverrestProcessor() throws Exception {
        IOException ioException = new IOException();
        doThrow(ioException).when(everrestProcessor).process(isA(ServletContainerRequest.class), isA(ContainerResponse.class), isA(EnvironmentContext.class));

        thrown.expect(exceptionSameInstanceMatcher(ioException));
        everrestServlet.service(request, response);
    }

    @Test
    public void wrapsCauseOfUnhandledExceptionWithServletException() throws Exception {
        Exception exception = new Exception();
        UnhandledException unhandledException = new UnhandledException(exception);

        doThrow(unhandledException).when(everrestProcessor).process(isA(ServletContainerRequest.class), isA(ContainerResponse.class), isA(EnvironmentContext.class));

        thrown.expect(ServletException.class);
        thrown.expectCause(exceptionSameInstanceMatcher(exception));
        everrestServlet.service(request, response);
    }

    @Test
    public void sendsErrorStatusWhenStatusIsSetInUnhandledException() throws Exception {
        UnhandledException unhandledException = new UnhandledException(403);

        doThrow(unhandledException).when(everrestProcessor).process(isA(ServletContainerRequest.class), isA(ContainerResponse.class), isA(EnvironmentContext.class));

        everrestServlet.service(request, response);
        verify(response).sendError(403);
    }

    private BaseMatcher<Throwable> exceptionSameInstanceMatcher(Exception expectedException) {
        return new BaseMatcher<Throwable>() {
            @Override
            public boolean matches(Object item) {
                return item == expectedException;
            }

            @Override
            public void describeTo(Description description) {
                description.appendText(String.format("Expected exception: %s", expectedException));
            }
        };
    }
}