com.google.inject.Asserts.java Source code

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Here is the source code for com.google.inject.Asserts.java

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/**
 * Copyright (C) 2008 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.inject;

import static com.google.inject.internal.InternalFlags.IncludeStackTraceOption;
import static com.google.inject.internal.InternalFlags.getIncludeStackTraceOption;
import static junit.framework.Assert.assertEquals;
import static junit.framework.Assert.assertNotNull;
import static junit.framework.Assert.assertTrue;

import com.google.common.base.Function;
import com.google.common.base.Joiner;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;

import junit.framework.Assert;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.NotSerializableException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

/**
 * @author jessewilson@google.com (Jesse Wilson)
 */
public class Asserts {
    private Asserts() {
    }

    /**
     * Returns the String that would appear in an error message for this chain of classes 
     * as modules.
     */
    public static String asModuleChain(Class... classes) {
        return Joiner.on(" -> ").appendTo(new StringBuilder(" (via modules: "),
                Iterables.transform(ImmutableList.copyOf(classes), new Function<Class, String>() {
                    @Override
                    public String apply(Class input) {
                        return input.getName();
                    }
                })).append(")").toString();
    }

    /**
     * Returns the source file appears in error messages based on {@link 
     * #getIncludeStackTraceOption()} value.
     */
    public static String getDeclaringSourcePart(Class clazz) {
        if (getIncludeStackTraceOption() == IncludeStackTraceOption.OFF) {
            return ".configure(Unknown Source";
        }
        return ".configure(" + clazz.getSimpleName() + ".java:";
    }

    /**
     * Returns true if {@link #getIncludeStackTraceOption()} returns {@link
     * IncludeStackTraceOption#OFF}.
     */
    public static boolean isIncludeStackTraceOff() {
        return getIncludeStackTraceOption() == IncludeStackTraceOption.OFF;
    }

    /**
     * Returns true if {@link #getIncludeStackTraceOption()} returns {@link
     * IncludeStackTraceOption#COMPLETE}.
     */
    public static boolean isIncludeStackTraceComplete() {
        return getIncludeStackTraceOption() == IncludeStackTraceOption.COMPLETE;
    }

    /**
     * Fails unless {@code expected.equals(actual)}, {@code
     * actual.equals(expected)} and their hash codes are equal. This is useful
     * for testing the equals method itself.
     */
    public static void assertEqualsBothWays(Object expected, Object actual) {
        assertNotNull(expected);
        assertNotNull(actual);
        assertEquals("expected.equals(actual)", actual, expected);
        assertEquals("actual.equals(expected)", expected, actual);
        assertEquals("hashCode", expected.hashCode(), actual.hashCode());
    }

    /**
     * Fails unless {@code text} includes all {@code substrings}, in order.
     */
    public static void assertContains(String text, String... substrings) {
        /*if[NO_AOP]
        // when we strip out bytecode manipulation, we lose the ability to generate some source lines.
        if (text.contains("(Unknown Source)")) {
          return;
        }
        end[NO_AOP]*/

        int startingFrom = 0;
        for (String substring : substrings) {
            int index = text.indexOf(substring, startingFrom);
            assertTrue(String.format("Expected \"%s\" to contain substring \"%s\"", text, substring),
                    index >= startingFrom);
            startingFrom = index + substring.length();
        }

        String lastSubstring = substrings[substrings.length - 1];
        assertTrue(String.format("Expected \"%s\" to contain substring \"%s\" only once),", text, lastSubstring),
                text.indexOf(lastSubstring, startingFrom) == -1);
    }

    /**
     * Fails unless {@code object} doesn't equal itself when reserialized.
     */
    public static void assertEqualWhenReserialized(Object object) throws IOException {
        Object reserialized = reserialize(object);
        assertEquals(object, reserialized);
        assertEquals(object.hashCode(), reserialized.hashCode());
    }

    /**
     * Fails unless {@code object} has the same toString value when reserialized.
     */
    public static void assertSimilarWhenReserialized(Object object) throws IOException {
        Object reserialized = reserialize(object);
        assertEquals(object.toString(), reserialized.toString());
    }

    public static <E> E reserialize(E original) throws IOException {
        try {
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            new ObjectOutputStream(out).writeObject(original);
            ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray());
            @SuppressWarnings("unchecked") // the reserialized type is assignable
            E reserialized = (E) new ObjectInputStream(in).readObject();
            return reserialized;
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        }
    }

    public static void assertNotSerializable(Object object) throws IOException {
        try {
            reserialize(object);
            Assert.fail();
        } catch (NotSerializableException expected) {
        }
    }
}