Testing GSON defaults - gson rev is 2.3.1

GsonTest.java

package org.apache.aurora.scheduler.http;

import java.util.List;

import com.google.gson.Gson;

import org.junit.Test;

import static java.util.Arrays.asList;
import static java.util.Collections.emptyList;

import static org.junit.Assert.assertEquals;

public class GsonTest {
  private static final Gson GSON = new Gson();
  private static final List<String> DEFAULT_STRINGS = asList("DEFAULT", "STRINGS");
  public static final String EMPTY_JSON_OBJECT = "{}";
  public static final String FULL_JSON_OBJECT = "{strings: []}";

  private static class MutableDefaultTest {
    private List<String> strings = DEFAULT_STRINGS;

    // Default constructor.
  }

  private static class ImmutableDefaultTest {
    private final List<String> strings = DEFAULT_STRINGS;

    // Default constructor.
  }

  private static class MutableEmptyOverrideTest {
    private List<String> strings = DEFAULT_STRINGS;

    private MutableEmptyOverrideTest() {
      // GSON constructor.
    }
  }

  private static class ImmutableEmptyOverrideTest {
    private final List<String> strings = DEFAULT_STRINGS;

    private ImmutableEmptyOverrideTest() {
      // GSON constructor.
    }
  }

  static class MutableInitializeOverrideTest {
    private List<String> strings;

    private MutableInitializeOverrideTest() {
      strings = DEFAULT_STRINGS;
    }
  }

  static class ImmutableInitializeOverrideTest {
    private final List<String> strings;

    ImmutableInitializeOverrideTest() {
      strings = DEFAULT_STRINGS;
    }
  }

  @Test
  public void testGsonDefaults() {
    assertEquals(DEFAULT_STRINGS, GSON.fromJson(EMPTY_JSON_OBJECT, MutableDefaultTest.class).strings);
    assertEquals(DEFAULT_STRINGS, GSON.fromJson(EMPTY_JSON_OBJECT, ImmutableDefaultTest.class).strings);
    assertEquals(DEFAULT_STRINGS, GSON.fromJson(EMPTY_JSON_OBJECT, MutableEmptyOverrideTest.class).strings);
    assertEquals(DEFAULT_STRINGS, GSON.fromJson(EMPTY_JSON_OBJECT, ImmutableEmptyOverrideTest.class).strings);
    assertEquals(DEFAULT_STRINGS, GSON.fromJson(EMPTY_JSON_OBJECT, MutableInitializeOverrideTest.class).strings);
    assertEquals(DEFAULT_STRINGS, GSON.fromJson(EMPTY_JSON_OBJECT, ImmutableInitializeOverrideTest.class).strings);

    assertEquals(emptyList(), GSON.fromJson(FULL_JSON_OBJECT, MutableDefaultTest.class).strings);
    assertEquals(emptyList(), GSON.fromJson(FULL_JSON_OBJECT, ImmutableDefaultTest.class).strings);
    assertEquals(emptyList(), GSON.fromJson(FULL_JSON_OBJECT, MutableEmptyOverrideTest.class).strings);
    assertEquals(emptyList(), GSON.fromJson(FULL_JSON_OBJECT, ImmutableEmptyOverrideTest.class).strings);
    assertEquals(emptyList(), GSON.fromJson(FULL_JSON_OBJECT, MutableInitializeOverrideTest.class).strings);
    assertEquals(emptyList(), GSON.fromJson(FULL_JSON_OBJECT, ImmutableInitializeOverrideTest.class).strings);
  }
}