GsonTest.java

/*
 * Copyright (C) 2016 The Gson Authors
 *
 * 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.gson;

import com.google.gson.internal.Excluder;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonWriter;
import com.google.gson.stream.MalformedJsonException;
import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;
import java.lang.reflect.Field;
import java.lang.reflect.Type;
import java.text.DateFormat;
import java.util.ArrayList;
import java.util.HashMap;
import junit.framework.TestCase;

/**
 * Unit tests for {@link Gson}.
 *
 * @author Ryan Harter
 */
public final class GsonTest extends TestCase {

  private static final Excluder CUSTOM_EXCLUDER = Excluder.DEFAULT
      .excludeFieldsWithoutExposeAnnotation()
      .disableInnerClassSerialization();

  private static final FieldNamingStrategy CUSTOM_FIELD_NAMING_STRATEGY = new FieldNamingStrategy() {
    @Override public String translateName(Field f) {
      return "foo";
    }
  };

  private static final ToNumberStrategy CUSTOM_OBJECT_TO_NUMBER_STRATEGY = ToNumberPolicy.DOUBLE;
  private static final ToNumberStrategy CUSTOM_NUMBER_TO_NUMBER_STRATEGY = ToNumberPolicy.LAZILY_PARSED_NUMBER;

  public void testOverridesDefaultExcluder() {
    Gson gson = new Gson(CUSTOM_EXCLUDER, CUSTOM_FIELD_NAMING_STRATEGY,
        new HashMap<Type, InstanceCreator<?>>(), true, false, true, false,
        true, true, false, true, LongSerializationPolicy.DEFAULT, null, DateFormat.DEFAULT,
        DateFormat.DEFAULT, new ArrayList<TypeAdapterFactory>(),
        new ArrayList<TypeAdapterFactory>(), new ArrayList<TypeAdapterFactory>(),
        CUSTOM_OBJECT_TO_NUMBER_STRATEGY, CUSTOM_NUMBER_TO_NUMBER_STRATEGY);

    assertEquals(CUSTOM_EXCLUDER, gson.excluder);
    assertEquals(CUSTOM_FIELD_NAMING_STRATEGY, gson.fieldNamingStrategy());
    assertEquals(true, gson.serializeNulls());
    assertEquals(false, gson.htmlSafe());
  }

  public void testClonedTypeAdapterFactoryListsAreIndependent() {
    Gson original = new Gson(CUSTOM_EXCLUDER, CUSTOM_FIELD_NAMING_STRATEGY,
        new HashMap<Type, InstanceCreator<?>>(), true, false, true, false,
        true, true, false, true, LongSerializationPolicy.DEFAULT, null, DateFormat.DEFAULT,
        DateFormat.DEFAULT, new ArrayList<TypeAdapterFactory>(),
        new ArrayList<TypeAdapterFactory>(), new ArrayList<TypeAdapterFactory>(),
        CUSTOM_OBJECT_TO_NUMBER_STRATEGY, CUSTOM_NUMBER_TO_NUMBER_STRATEGY);

    Gson clone = original.newBuilder()
        .registerTypeAdapter(Object.class, new TestTypeAdapter())
        .create();

    assertEquals(original.factories.size() + 1, clone.factories.size());
  }

  private static final class TestTypeAdapter extends TypeAdapter<Object> {
    @Override public void write(JsonWriter out, Object value) throws IOException {
      // Test stub.
    }
    @Override public Object read(JsonReader in) throws IOException { return null; }
  }

  public void testNewJsonWriter_Default() throws IOException {
    StringWriter writer = new StringWriter();
    JsonWriter jsonWriter = new Gson().newJsonWriter(writer);
    jsonWriter.beginObject();
    jsonWriter.name("test");
    jsonWriter.nullValue();
    jsonWriter.name("<test2");
    jsonWriter.value(true);
    jsonWriter.endObject();

    try {
      // Additional top-level value
      jsonWriter.value(1);
      fail();
    } catch (IllegalStateException expected) {
      assertEquals("JSON must have only one top-level value.", expected.getMessage());
    }

    jsonWriter.close();
    assertEquals("{\"\\u003ctest2\":true}", writer.toString());
  }

  public void testNewJsonWriter_Custom() throws IOException {
    StringWriter writer = new StringWriter();
    JsonWriter jsonWriter = new GsonBuilder()
      .disableHtmlEscaping()
      .generateNonExecutableJson()
      .setPrettyPrinting()
      .serializeNulls()
      .setLenient()
      .create()
      .newJsonWriter(writer);
    jsonWriter.beginObject();
    jsonWriter.name("test");
    jsonWriter.nullValue();
    jsonWriter.name("<test2");
    jsonWriter.value(true);
    jsonWriter.endObject();

    // Additional top-level value
    jsonWriter.value(1);

    jsonWriter.close();
    assertEquals(")]}'\n{\n  \"test\": null,\n  \"<test2\": true\n}1", writer.toString());
  }

  public void testNewJsonReader_Default() throws IOException {
    String json = "test"; // String without quotes
    JsonReader jsonReader = new Gson().newJsonReader(new StringReader(json));
    try {
      jsonReader.nextString();
      fail();
    } catch (MalformedJsonException expected) {
    }
    jsonReader.close();
  }

  public void testNewJsonReader_Custom() throws IOException {
    String json = "test"; // String without quotes
    JsonReader jsonReader = new GsonBuilder()
      .setLenient()
      .create()
      .newJsonReader(new StringReader(json));
    assertEquals("test", jsonReader.nextString());
    jsonReader.close();
  }
}