GsonUtilTest.java

/**
 * Copyright (c) 2010 Darmstadt University of Technology.
 * 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:
 *    Marcel Bruch - initial API and implementation.
 */
package org.eclipse.recommenders.utils.gson;

import static org.eclipse.recommenders.utils.Constants.DOT_JSON;
import static org.junit.Assert.*;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.util.Map;

import org.junit.Test;

import com.google.common.collect.HashMultimap;
import com.google.common.collect.Multimap;
import com.google.gson.reflect.TypeToken;

public class GsonUtilTest {

    @Test
    public void testEmptyFileDeserialization() throws IOException {
        // setup
        File f = File.createTempFile("tmp", DOT_JSON);
        f.deleteOnExit();

        // exercise
        Object res = GsonUtil.deserialize(f, new TypeToken<Map<File, String>>() {
        }.getType());

        // it's actually null :)
        assertNull(res);
    }

    @Test
    public void testPrettyPrint() {
        final GsonTestStruct struct = GsonTestStruct.create("string", 0.43d, "s1", "s2");
        GsonUtil.serialize(struct);
    }

    @Test
    public void testSerializationRoundTrip() {
        // setup
        final GsonTestStruct input = GsonTestStruct.create("string", 0.43d, "s1", "s2");
        // exercise
        final String json = GsonUtil.serialize(input);
        final GsonTestStruct output = GsonUtil.deserialize(json, GsonTestStruct.class);
        // verify
        assertEquals(input, output);
    }

    @Test
    public void testSerializationRoundTrip_ViaInputStream() {
        // setup
        final GsonTestStruct input = GsonTestStruct.create("string", 0.43d, "s1", "s2");
        // exercise
        final String json = GsonUtil.serialize(input);
        final GsonTestStruct output = GsonUtil.deserialize(new ByteArrayInputStream(json.getBytes()),
                GsonTestStruct.class);
        // verify
        assertEquals(input, output);
    }

    @Test
    public void testSerializationPrettyRoundTrip_ViaInputStream() {
        // setup
        final GsonTestStruct input = GsonTestStruct.create("string", 0.43d, "s1", "s2");
        // exercise
        final String prettyJson = GsonUtil.serialize(input);
        final GsonTestStruct output = GsonUtil.deserialize(prettyJson, GsonTestStruct.class);
        // verify
        assertEquals(input, output);
    }

    @Test
    public void testMultimapOfStrings() {
        // setup:
        final Multimap<String, String> map = HashMultimap.create();
        map.put("key", "value1");
        map.put("key", "value2");
        // exercise:
        final String json = GsonUtil.getInstance().toJson(map, new TypeToken<Multimap<String, String>>() {
        }.getType());
        final Multimap<String, String> output = GsonUtil.deserialize(json, new TypeToken<Multimap<String, String>>() {
        }.getType());
        // verify
        assertEquals(map, output);
    }

}