Several breaking changes

2022-05-17 21:20:10 +02:00 · 2022-05-17 21:20:10 +02:00 · dc4e61ac7b
parent ccf30b23e8
commit dc4e61ac7b
47 changed files with 472 additions and 310 deletions
--- a/.gitignore
+++ b/.gitignore
@ -20,3 +20,4 @@ build
 .DS_Store

 examples/android-proguard-example/gen
+.attach_pid*
--- a/README.md
+++ b/README.md
@ -1,7 +1,17 @@
 # About this fork

-This fork of Gson adds support for writing comments in JsonWriter.
-To do this, JsonWriter and CommentsTest were adjusted.
+This fork of Gson adds several features which were originally denied due to Gson's maintenance status.
+Among them are:
+- support for writing comments
+- collections with single entries without array syntax (`"single entry"` can become a `List` or array)
+- stricter leniency enforcement from the main Gson class (`toJson`, `fromJson` will respect the choice)
+- slightly better error messages
+- skipping empty entries in arrays (`["one",, "two",]`)
+- optionally omitting quotes around entry names like in Json5
+- support for hexadecimal integers
+
+This means the only thing lacking for Json5 support is trailing commas in objects
+
 Please be aware that I also increased the minimum java version to 11
 To use this, add the following:
 ```groovy
--- a/gson/src/main/java/com/google/gson/Gson.java
+++ b/gson/src/main/java/com/google/gson/Gson.java
@ -35,12 +35,7 @@ import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.atomic.AtomicLongArray;

-import com.google.gson.internal.ConstructorConstructor;
-import com.google.gson.internal.Excluder;
-import com.google.gson.internal.GsonBuildConfig;
-import com.google.gson.internal.LazilyParsedNumber;
-import com.google.gson.internal.Primitives;
-import com.google.gson.internal.Streams;
+import com.google.gson.internal.*;
 import com.google.gson.internal.bind.ArrayTypeAdapter;
 import com.google.gson.internal.bind.CollectionTypeAdapterFactory;
 import com.google.gson.internal.bind.DateTypeAdapter;
@ -104,23 +99,6 @@ import com.google.gson.stream.MalformedJsonException;
 * @author Jesse Wilson
 */
 public final class Gson {
-  static final boolean DEFAULT_JSON_NON_EXECUTABLE = false;
-  static final boolean DEFAULT_LENIENT = false;
-  static final boolean DEFAULT_PRETTY_PRINT = false;
-  static final boolean DEFAULT_ESCAPE_HTML = true;
-  static final boolean DEFAULT_SERIALIZE_NULLS = false;
-  static final boolean DEFAULT_COMPLEX_MAP_KEYS = false;
-  static final boolean DEFAULT_DUPLICATE_MAP_KEYS = false;
-  static final boolean DEFAULT_SPECIALIZE_FLOAT_VALUES = false;
-  static final boolean DEFAULT_USE_JDK_UNSAFE = true;
-  static final String DEFAULT_DATE_PATTERN = null;
-  static final FieldNamingStrategy DEFAULT_FIELD_NAMING_STRATEGY = FieldNamingPolicy.IDENTITY;
-  static final ToNumberStrategy DEFAULT_OBJECT_TO_NUMBER_STRATEGY = ToNumberPolicy.DOUBLE;
-  static final ToNumberStrategy DEFAULT_NUMBER_TO_NUMBER_STRATEGY = ToNumberPolicy.LAZILY_PARSED_NUMBER;
-
-  private static final TypeToken<?> NULL_KEY_SURROGATE = TypeToken.get(Object.class);
-  private static final String JSON_NON_EXECUTABLE_PREFIX = ")]}'\n";
-
  /**
   * This thread local guards against reentrant calls to getAdapter(). In
   * certain object graphs, creating an adapter for a type may recursively
@ -148,6 +126,7 @@ public final class Gson {
  final boolean htmlSafe;
  final boolean prettyPrinting;
  final boolean lenient;
+  final boolean omitQuotes;
  final boolean serializeSpecialFloatingPointValues;
  final boolean useJdkUnsafe;
  final String datePattern;
@ -195,21 +174,21 @@ public final class Gson {
   * </ul>
   */
  public Gson() {
-    this(Excluder.DEFAULT, DEFAULT_FIELD_NAMING_STRATEGY,
-        Collections.<Type, InstanceCreator<?>>emptyMap(), DEFAULT_SERIALIZE_NULLS,
-        DEFAULT_COMPLEX_MAP_KEYS, DEFAULT_DUPLICATE_MAP_KEYS, DEFAULT_JSON_NON_EXECUTABLE, DEFAULT_ESCAPE_HTML,
-        DEFAULT_PRETTY_PRINT, DEFAULT_LENIENT, DEFAULT_SPECIALIZE_FLOAT_VALUES,
-        DEFAULT_USE_JDK_UNSAFE,
-        LongSerializationPolicy.DEFAULT, DEFAULT_DATE_PATTERN, DateFormat.DEFAULT, DateFormat.DEFAULT,
+    this(Excluder.DEFAULT, DefaultConfig.DEFAULT_FIELD_NAMING_STRATEGY,
+        Collections.<Type, InstanceCreator<?>>emptyMap(), DefaultConfig.DEFAULT_SERIALIZE_NULLS,
+        DefaultConfig.DEFAULT_COMPLEX_MAP_KEYS, DefaultConfig.DEFAULT_DUPLICATE_MAP_KEYS, DefaultConfig.DEFAULT_JSON_NON_EXECUTABLE, DefaultConfig.DEFAULT_ESCAPE_HTML,
+        DefaultConfig.DEFAULT_PRETTY_PRINT, true, DefaultConfig.DEFAULT_OMIT_QUOTES, DefaultConfig.DEFAULT_SPECIALIZE_FLOAT_VALUES,
+        DefaultConfig.DEFAULT_USE_JDK_UNSAFE,
+        LongSerializationPolicy.DEFAULT, DefaultConfig.DEFAULT_DATE_PATTERN, DateFormat.DEFAULT, DateFormat.DEFAULT,
        Collections.<TypeAdapterFactory>emptyList(), Collections.<TypeAdapterFactory>emptyList(),
-        Collections.<TypeAdapterFactory>emptyList(), DEFAULT_OBJECT_TO_NUMBER_STRATEGY, DEFAULT_NUMBER_TO_NUMBER_STRATEGY,
+        Collections.<TypeAdapterFactory>emptyList(), DefaultConfig.DEFAULT_OBJECT_TO_NUMBER_STRATEGY, DefaultConfig.DEFAULT_NUMBER_TO_NUMBER_STRATEGY,
        Collections.<ReflectionAccessFilter>emptyList());
  }

  Gson(Excluder excluder, FieldNamingStrategy fieldNamingStrategy,
      Map<Type, InstanceCreator<?>> instanceCreators, boolean serializeNulls,
      boolean complexMapKeySerialization, boolean duplicateMapKeyDeserialization, boolean generateNonExecutableGson, boolean htmlSafe,
-      boolean prettyPrinting, boolean lenient, boolean serializeSpecialFloatingPointValues,
+      boolean prettyPrinting, boolean lenient, boolean omitQuotes, boolean serializeSpecialFloatingPointValues,
      boolean useJdkUnsafe,
      LongSerializationPolicy longSerializationPolicy, String datePattern, int dateStyle,
      int timeStyle, List<TypeAdapterFactory> builderFactories,
@ -228,6 +207,7 @@ public final class Gson {
    this.htmlSafe = htmlSafe;
    this.prettyPrinting = prettyPrinting;
    this.lenient = lenient;
+    this.omitQuotes = omitQuotes;
    this.serializeSpecialFloatingPointValues = serializeSpecialFloatingPointValues;
    this.useJdkUnsafe = useJdkUnsafe;
    this.longSerializationPolicy = longSerializationPolicy;
@ -481,7 +461,7 @@ public final class Gson {
   */
  @SuppressWarnings("unchecked")
  public <T> TypeAdapter<T> getAdapter(TypeToken<T> type) {
-    TypeAdapter<?> cached = typeTokenCache.get(type == null ? NULL_KEY_SURROGATE : type);
+    TypeAdapter<?> cached = typeTokenCache.get(type == null ? DefaultConfig.NULL_KEY_SURROGATE : type);
    if (cached != null) {
      return (TypeAdapter<T>) cached;
    }
@ -745,7 +725,9 @@ public final class Gson {
  public void toJson(Object src, Type typeOfSrc, JsonWriter writer) throws JsonIOException {
    TypeAdapter<?> adapter = getAdapter(TypeToken.get(typeOfSrc));
    boolean oldLenient = writer.isLenient();
-    writer.setLenient(true);
+    writer.setLenient(lenient);
+    boolean oldOmitQuotes = writer.getOmitQuotes();
+    writer.setOmitQuotes(omitQuotes);
    boolean oldHtmlSafe = writer.isHtmlSafe();
    writer.setHtmlSafe(htmlSafe);
    boolean oldSerializeNulls = writer.getSerializeNulls();
@ -760,6 +742,7 @@ public final class Gson {
      throw error;
    } finally {
      writer.setLenient(oldLenient);
+      writer.setOmitQuotes(oldOmitQuotes);
      writer.setHtmlSafe(oldHtmlSafe);
      writer.setSerializeNulls(oldSerializeNulls);
    }
@ -804,12 +787,13 @@ public final class Gson {
   *   <li>{@link GsonBuilder#generateNonExecutableJson()}</li>
   *   <li>{@link GsonBuilder#serializeNulls()}</li>
   *   <li>{@link GsonBuilder#setLenient()}</li>
+   *   <li>{@link GsonBuilder#setOmitQuotes()}</li>
   *   <li>{@link GsonBuilder#setPrettyPrinting()}</li>
   * </ul>
   */
  public JsonWriter newJsonWriter(Writer writer) throws IOException {
    if (generateNonExecutableJson) {
-      writer.write(JSON_NON_EXECUTABLE_PREFIX);
+      writer.write(DefaultConfig.JSON_NON_EXECUTABLE_PREFIX);
    }
    JsonWriter jsonWriter = new JsonWriter(writer);
    if (prettyPrinting) {
@ -817,6 +801,7 @@ public final class Gson {
    }
    jsonWriter.setHtmlSafe(htmlSafe);
    jsonWriter.setLenient(lenient);
+    jsonWriter.setOmitQuotes(omitQuotes);
    jsonWriter.setSerializeNulls(serializeNulls);
    return jsonWriter;
  }
@ -841,7 +826,9 @@ public final class Gson {
   */
  public void toJson(JsonElement jsonElement, JsonWriter writer) throws JsonIOException {
    boolean oldLenient = writer.isLenient();
-    writer.setLenient(true);
+    writer.setLenient(lenient);
+    boolean oldOmitQuotes = writer.getOmitQuotes();
+    writer.setOmitQuotes(omitQuotes);
    boolean oldHtmlSafe = writer.isHtmlSafe();
    writer.setHtmlSafe(htmlSafe);
    boolean oldSerializeNulls = writer.getSerializeNulls();
@ -856,6 +843,7 @@ public final class Gson {
      throw error;
    } finally {
      writer.setLenient(oldLenient);
+      writer.setOmitQuotes(oldOmitQuotes);
      writer.setHtmlSafe(oldHtmlSafe);
      writer.setSerializeNulls(oldSerializeNulls);
    }
@ -989,7 +977,7 @@ public final class Gson {
  public <T> T fromJson(JsonReader reader, Type typeOfT) throws JsonIOException, JsonSyntaxException {
    boolean isEmpty = true;
    boolean oldLenient = reader.isLenient();
-    reader.setLenient(true);
+    reader.setLenient(lenient);
    try {
      reader.peek();
      isEmpty = false;
--- a/gson/src/main/java/com/google/gson/GsonBuilder.java
+++ b/gson/src/main/java/com/google/gson/GsonBuilder.java
@ -35,18 +35,7 @@ import com.google.gson.internal.sql.SqlTypesSupport;
 import com.google.gson.reflect.TypeToken;
 import com.google.gson.stream.JsonReader;

-import static com.google.gson.Gson.DEFAULT_COMPLEX_MAP_KEYS;
-import static com.google.gson.Gson.DEFAULT_DATE_PATTERN;
-import static com.google.gson.Gson.DEFAULT_DUPLICATE_MAP_KEYS;
-import static com.google.gson.Gson.DEFAULT_ESCAPE_HTML;
-import static com.google.gson.Gson.DEFAULT_JSON_NON_EXECUTABLE;
-import static com.google.gson.Gson.DEFAULT_LENIENT;
-import static com.google.gson.Gson.DEFAULT_NUMBER_TO_NUMBER_STRATEGY;
-import static com.google.gson.Gson.DEFAULT_OBJECT_TO_NUMBER_STRATEGY;
-import static com.google.gson.Gson.DEFAULT_PRETTY_PRINT;
-import static com.google.gson.Gson.DEFAULT_SERIALIZE_NULLS;
-import static com.google.gson.Gson.DEFAULT_SPECIALIZE_FLOAT_VALUES;
-import static com.google.gson.Gson.DEFAULT_USE_JDK_UNSAFE;
+import static com.google.gson.internal.DefaultConfig.*;

 /**
 * <p>Use this builder to construct a {@link Gson} instance when you need to set configuration
@ -100,6 +89,7 @@ public final class GsonBuilder {
  private boolean prettyPrinting = DEFAULT_PRETTY_PRINT;
  private boolean generateNonExecutableJson = DEFAULT_JSON_NON_EXECUTABLE;
  private boolean lenient = DEFAULT_LENIENT;
+  private boolean omitQuotes = DEFAULT_OMIT_QUOTES;
  private boolean useJdkUnsafe = DEFAULT_USE_JDK_UNSAFE;
  private ToNumberStrategy objectToNumberStrategy = DEFAULT_OBJECT_TO_NUMBER_STRATEGY;
  private ToNumberStrategy numberToNumberStrategy = DEFAULT_NUMBER_TO_NUMBER_STRATEGY;
@ -131,6 +121,7 @@ public final class GsonBuilder {
    this.escapeHtmlChars = gson.htmlSafe;
    this.prettyPrinting = gson.prettyPrinting;
    this.lenient = gson.lenient;
+    this.omitQuotes = gson.omitQuotes;
    this.serializeSpecialFloatingPointValues = gson.serializeSpecialFloatingPointValues;
    this.longSerializationPolicy = gson.longSerializationPolicy;
    this.datePattern = gson.datePattern;
@ -456,6 +447,15 @@ public final class GsonBuilder {
    return this;
  }

+  /**
+   * By default, Gson always writes quotes around entry names.
+   * This option allows omitting quotes if the name is alphanumeric.
+   */
+  public GsonBuilder setOmitQuotes() {
+    omitQuotes = true;
+    return this;
+  }
+
  /**
   * By default, Gson escapes HTML characters such as &lt; &gt; etc. Use this option to configure
   * Gson to pass-through HTML characters as is.
@ -694,7 +694,7 @@ public final class GsonBuilder {

    return new Gson(excluder, fieldNamingPolicy, new HashMap<>(instanceCreators),
        serializeNulls, complexMapKeySerialization, duplicateMapKeyDeserialization,
-        generateNonExecutableJson, escapeHtmlChars, prettyPrinting, lenient,
+        generateNonExecutableJson, escapeHtmlChars, prettyPrinting, lenient, omitQuotes,
        serializeSpecialFloatingPointValues, useJdkUnsafe, longSerializationPolicy,
        datePattern, dateStyle, timeStyle, new ArrayList<>(this.factories),
        new ArrayList<>(this.hierarchyFactories), factories,
--- a/gson/src/main/java/com/google/gson/internal/DefaultConfig.java
+++ b/gson/src/main/java/com/google/gson/internal/DefaultConfig.java
@ -0,0 +1,23 @@
+package com.google.gson.internal;
+
+import com.google.gson.*;
+import com.google.gson.reflect.*;
+
+public class DefaultConfig {
+    public static final boolean DEFAULT_JSON_NON_EXECUTABLE = false;
+    public static final boolean DEFAULT_LENIENT = false;
+    public static final boolean DEFAULT_OMIT_QUOTES = false;
+    public static final boolean DEFAULT_PRETTY_PRINT = false;
+    public static final boolean DEFAULT_ESCAPE_HTML = true;
+    public static final boolean DEFAULT_SERIALIZE_NULLS = false;
+    public static final boolean DEFAULT_COMPLEX_MAP_KEYS = false;
+    public static final boolean DEFAULT_DUPLICATE_MAP_KEYS = false;
+    public static final boolean DEFAULT_SPECIALIZE_FLOAT_VALUES = false;
+    public static final boolean DEFAULT_USE_JDK_UNSAFE = true;
+    public static final String DEFAULT_DATE_PATTERN = null;
+    public static final FieldNamingStrategy DEFAULT_FIELD_NAMING_STRATEGY = FieldNamingPolicy.IDENTITY;
+    public static final ToNumberStrategy DEFAULT_OBJECT_TO_NUMBER_STRATEGY = ToNumberPolicy.DOUBLE;
+    public static final ToNumberStrategy DEFAULT_NUMBER_TO_NUMBER_STRATEGY = ToNumberPolicy.LAZILY_PARSED_NUMBER;
+    public static final TypeToken<?> NULL_KEY_SURROGATE = TypeToken.get(Object.class);
+    public static final String JSON_NON_EXECUTABLE_PREFIX = ")]}'\n";
+}
--- a/gson/src/main/java/com/google/gson/internal/bind/ArrayTypeAdapter.java
+++ b/gson/src/main/java/com/google/gson/internal/bind/ArrayTypeAdapter.java
@ -65,6 +65,13 @@ public final class ArrayTypeAdapter<E> extends TypeAdapter<Object> {
      in.nextNull();
      return null;
    }
+    Object array;
+    if (in.isLenient() && in.peek() != JsonToken.BEGIN_ARRAY) {
+      // Coerce
+      array = Array.newInstance(componentType, 1);
+      Array.set(array, 0, componentTypeAdapter.read(in));
+      return array;
+    }

    List<E> list = new ArrayList<>();
    in.beginArray();
@ -75,7 +82,7 @@ public final class ArrayTypeAdapter<E> extends TypeAdapter<Object> {
    in.endArray();

    int size = list.size();
-    Object array = Array.newInstance(componentType, size);
+    array = Array.newInstance(componentType, size);
    for (int i = 0; i < size; i++) {
      Array.set(array, i, list.get(i));
    }
--- a/gson/src/main/java/com/google/gson/internal/bind/CollectionTypeAdapterFactory.java
+++ b/gson/src/main/java/com/google/gson/internal/bind/CollectionTypeAdapterFactory.java
@ -77,12 +77,17 @@ public final class CollectionTypeAdapterFactory implements TypeAdapterFactory {
      }

      Collection<E> collection = constructor.construct();
-      in.beginArray();
-      while (in.hasNext()) {
-        E instance = elementTypeAdapter.read(in);
-        collection.add(instance);
+      if (!in.isLenient() || in.peek() == JsonToken.BEGIN_ARRAY) {
+        in.beginArray();
+        while (in.hasNext()) {
+          E instance = elementTypeAdapter.read(in);
+          collection.add(instance);
+        }
+        in.endArray();
+      } else {
+        // Coerce
+        collection.add(elementTypeAdapter.read(in));
      }
-      in.endArray();
      return collection;
    }

--- a/gson/src/main/java/com/google/gson/stream/JsonReader.java
+++ b/gson/src/main/java/com/google/gson/stream/JsonReader.java
@ -16,7 +16,7 @@

 package com.google.gson.stream;

-import com.google.gson.internal.JsonReaderInternalAccess;
+import com.google.gson.internal.*;
 import com.google.gson.internal.bind.JsonTreeReader;
 import java.io.Closeable;
 import java.io.EOFException;
@ -226,7 +226,7 @@ public class JsonReader implements Closeable {
  private final Reader in;

  /** True to accept non-spec compliant JSON */
-  private boolean lenient = false;
+  private boolean lenient = DefaultConfig.DEFAULT_LENIENT;

  static final int BUFFER_SIZE = 1024;
  /**
@ -315,8 +315,7 @@ public class JsonReader implements Closeable {
   *   <li>Names that are unquoted or {@code 'single quoted'}.
   *   <li>Strings that are unquoted or {@code 'single quoted'}.
   *   <li>Array elements separated by {@code ;} instead of {@code ,}.
-   *   <li>Unnecessary array separators. These are interpreted as if null
-   *       was the omitted value.
+   *   <li>Unnecessary array separators. These are ignored.
   *   <li>Names and values separated by {@code =} or {@code =>} instead of
   *       {@code :}.
   *   <li>Name/value pairs separated by {@code ;} instead of {@code ,}.
@ -473,7 +472,7 @@ public class JsonReader implements Closeable {
      case ',':
        break;
      default:
-        throw syntaxError("Unterminated array");
+        throw syntaxError("Unterminated array at " + (char)c);
      }
    } else if (peekStack == JsonScope.EMPTY_OBJECT || peekStack == JsonScope.NONEMPTY_OBJECT) {
      stack[stackSize - 1] = JsonScope.DANGLING_NAME;
@ -488,7 +487,7 @@ public class JsonReader implements Closeable {
        case ',':
          break;
        default:
-          throw syntaxError("Unterminated object");
+          throw syntaxError("Unterminated object at " + (char)c);
        }
      }
      int c = nextNonWhitespace(true);
@ -546,35 +545,8 @@ public class JsonReader implements Closeable {
      throw new IllegalStateException("JsonReader is closed");
    }

-    int c = nextNonWhitespace(true);
-    switch (c) {
-    case ']':
-      if (peekStack == JsonScope.EMPTY_ARRAY) {
-        return peeked = PEEKED_END_ARRAY;
-      }
-      // fall-through to handle ",]"
-    case ';':
-    case ',':
-      // In lenient mode, a 0-length literal in an array means 'null'.
-      if (peekStack == JsonScope.EMPTY_ARRAY || peekStack == JsonScope.NONEMPTY_ARRAY) {
-        checkLenient();
-        pos--;
-        return peeked = PEEKED_NULL;
-      } else {
-        throw syntaxError("Unexpected value");
-      }
-    case '\'':
-      checkLenient();
-      return peeked = PEEKED_SINGLE_QUOTED;
-    case '"':
-      return peeked = PEEKED_DOUBLE_QUOTED;
-    case '[':
-      return peeked = PEEKED_BEGIN_ARRAY;
-    case '{':
-      return peeked = PEEKED_BEGIN_OBJECT;
-    default:
-      pos--; // Don't consume the first character in a literal value.
-    }
+    if (checkNextNonWhitespace(peekStack))
+      return peeked;

    int result = peekKeyword();
    if (result != PEEKED_NONE) {
@ -594,6 +566,45 @@ public class JsonReader implements Closeable {
    return peeked = PEEKED_UNQUOTED;
  }

+  private boolean checkNextNonWhitespace(int peekStack) throws IOException {
+    int c = nextNonWhitespace(true);
+    switch (c) {
+      case ']':
+        if (peekStack == JsonScope.EMPTY_ARRAY || peekStack == JsonScope.NONEMPTY_ARRAY) {
+          peeked = PEEKED_END_ARRAY;
+          return true;
+        }
+        throw syntaxError("Unexpected value");
+      case ';':
+      case ',':
+        // In lenient mode, a 0-length literal in an array should be skipped.
+        if (peekStack == JsonScope.EMPTY_ARRAY || peekStack == JsonScope.NONEMPTY_ARRAY) {
+          checkLenient();
+          //pos--;
+          //peeked = PEEKED_NULL;
+          return checkNextNonWhitespace(peekStack);
+        } else {
+          throw syntaxError("Unexpected value");
+        }
+      case '\'':
+        checkLenient();
+        peeked = PEEKED_SINGLE_QUOTED;
+        return true;
+      case '"':
+        peeked = PEEKED_DOUBLE_QUOTED;
+        return true;
+      case '[':
+        peeked = PEEKED_BEGIN_ARRAY;
+        return true;
+      case '{':
+        peeked = PEEKED_BEGIN_OBJECT;
+        return true;
+      default:
+        pos--; // Don't consume the first character in a literal value.
+    }
+    return false;
+  }
+
  private int peekKeyword() throws IOException {
    // Figure out which keyword we're matching against by its first character.
    char c = buffer[pos];
@ -1198,10 +1209,14 @@ public class JsonReader implements Closeable {
    }

    peeked = PEEKED_BUFFERED;
-    double asDouble = Double.parseDouble(peekedString); // don't catch this NumberFormatException.
-    result = (int) asDouble;
-    if (result != asDouble) { // Make sure no precision was lost casting to 'int'.
-      throw new NumberFormatException("Expected an int but was " + peekedString + locationString());
+    if (peekedString.startsWith("0x")) {
+      result = Integer.decode(peekedString);
+    } else {
+      double asDouble = Double.parseDouble(peekedString); // don't catch this NumberFormatException.
+      result = (int) asDouble;
+      if (result != asDouble) { // Make sure no precision was lost casting to 'int'.
+        throw new NumberFormatException("Expected an int but was " + peekedString + locationString());
+      }
    }
    peekedString = null;
    peeked = PEEKED_NONE;
@ -1254,7 +1269,8 @@ public class JsonReader implements Closeable {
        pos += peekedNumberLength;
      }
      peeked = PEEKED_NONE;
-    } while (count != 0);
+    } while (count > 0);
+    if (count < 0) throw new IllegalStateException("Attempt to skip led outside its parent");

    pathIndices[stackSize - 1]++;
    pathNames[stackSize - 1] = "null";
@ -1452,7 +1468,8 @@ public class JsonReader implements Closeable {
  String locationString() {
    int line = lineNumber + 1;
    int column = pos - lineStart + 1;
-    return " at line " + line + " column " + column + " path " + getPath();
+    String charInterjection = pos < buffer.length ? " (char '" + buffer[pos] + "')" : "";
+    return " at line " + line + " column " + column + charInterjection + " path " + getPath();
  }

  private String getPath(boolean usePreviousPath) {
--- a/gson/src/main/java/com/google/gson/stream/JsonWriter.java
+++ b/gson/src/main/java/com/google/gson/stream/JsonWriter.java
@ -16,6 +16,8 @@

 package com.google.gson.stream;

+import com.google.gson.internal.*;
+
 import java.io.Closeable;
 import java.io.Flushable;
 import java.io.IOException;
@ -190,7 +192,9 @@ public class JsonWriter implements Closeable, Flushable {
   */
  private String separator = ":";

-  private boolean lenient;
+  private boolean lenient = DefaultConfig.DEFAULT_LENIENT;
+
+  private boolean omitQuotes = DefaultConfig.DEFAULT_OMIT_QUOTES;

  private boolean htmlSafe;

@ -286,11 +290,25 @@ public class JsonWriter implements Closeable, Flushable {
    return serializeNulls;
  }

+  /**
+   * Sets whether serialized entry names may omit quotes (like in json5)
+   * The default is false
+   */
+  public final void setOmitQuotes(boolean omitQuotes) {
+    this.omitQuotes = omitQuotes;
+  }
+
+  public final boolean getOmitQuotes() {
+    return omitQuotes;
+  }
+
  /**
   * Insert a comment at the current location.
   * May create a new line.
+   * This writer MUST be lenient to use this
   */
  public JsonWriter comment(String comment) throws IOException {
+    if (!lenient) throw new MalformedJsonException("Cannot write comment in non-lenient JsonWriter.");
    if (comment == null || comment.isBlank()) return this;
    String[] parts = comment.split("\n");
    if (indent == null) {
@ -424,7 +442,12 @@ public class JsonWriter implements Closeable, Flushable {
  private void writeDeferredName() throws IOException {
    if (deferredName != null) {
      beforeName();
-      string(deferredName);
+      if (omitQuotes && deferredName.matches("[a-zA-Z_$][\\w$]*")) {
+        out.write(deferredName);
+      }
+      else {
+        string(deferredName);
+      }
      deferredName = null;
    }
  }
--- a/gson/src/test/java/com/google/gson/GsonTest.java
+++ b/gson/src/test/java/com/google/gson/GsonTest.java
@ -54,7 +54,7 @@ public final class GsonTest extends TestCase {
  public void testOverridesDefaultExcluder() {
    Gson gson = new Gson(CUSTOM_EXCLUDER, CUSTOM_FIELD_NAMING_STRATEGY,
        new HashMap<Type, InstanceCreator<?>>(), true, false, false, true, false,
-        true, true, false, true, LongSerializationPolicy.DEFAULT, null, DateFormat.DEFAULT,
+        true, true, false, 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,
@ -69,7 +69,7 @@ public final class GsonTest extends TestCase {
  public void testClonedTypeAdapterFactoryListsAreIndependent() {
    Gson original = new Gson(CUSTOM_EXCLUDER, CUSTOM_FIELD_NAMING_STRATEGY,
        new HashMap<Type, InstanceCreator<?>>(), true, false, false, true, false,
-        true, true, false, true, LongSerializationPolicy.DEFAULT, null, DateFormat.DEFAULT,
+        true, true, false, 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,
@ -91,7 +91,7 @@ public final class GsonTest extends TestCase {

  public void testNewJsonWriter_Default() throws IOException {
    StringWriter writer = new StringWriter();
-    JsonWriter jsonWriter = new Gson().newJsonWriter(writer);
+    JsonWriter jsonWriter = new GsonBuilder().create().newJsonWriter(writer);
    jsonWriter.beginObject();
    jsonWriter.name("test");
    jsonWriter.nullValue();
@ -137,7 +137,7 @@ public final class GsonTest extends TestCase {

  public void testNewJsonReader_Default() throws IOException {
    String json = "test"; // String without quotes
-    JsonReader jsonReader = new Gson().newJsonReader(new StringReader(json));
+    JsonReader jsonReader = new GsonBuilder().create().newJsonReader(new StringReader(json));
    try {
      jsonReader.nextString();
      fail();
--- a/gson/src/test/java/com/google/gson/MixedStreamTest.java
+++ b/gson/src/test/java/com/google/gson/MixedStreamTest.java
@ -203,7 +203,7 @@ public final class MixedStreamTest extends TestCase {

    StringWriter writer = new StringWriter();
    JsonWriter jsonWriter = new JsonWriter(writer);
-    new GsonBuilder().serializeSpecialFloatingPointValues().create()
+    new GsonBuilder().setLenient().serializeSpecialFloatingPointValues().create()
        .toJson(doubles, type, jsonWriter);
    assertEquals("[NaN,-Infinity,Infinity,-0.0,0.5,0.0]", writer.toString());

--- a/gson/src/test/java/com/google/gson/ToNumberPolicyTest.java
+++ b/gson/src/test/java/com/google/gson/ToNumberPolicyTest.java
@ -33,7 +33,7 @@ public class ToNumberPolicyTest extends TestCase {
      strategy.readNumber(fromString("1e400"));
      fail();
    } catch (MalformedJsonException expected) {
-      assertEquals("JSON forbids NaN and infinities: Infinity at line 1 column 6 path $", expected.getMessage());
+      assertEquals("JSON forbids NaN and infinities: Infinity at line 1 column 6 (char '\0') path $", expected.getMessage());
    }
    try {
      strategy.readNumber(fromString("\"not-a-number\""));
@ -74,19 +74,19 @@ public class ToNumberPolicyTest extends TestCase {
      strategy.readNumber(fromString("NaN"));
      fail();
    } catch (MalformedJsonException expected) {
-      assertEquals("Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $", expected.getMessage());
+      assertEquals("Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 (char 'N') path $", expected.getMessage());
    }
    try {
      strategy.readNumber(fromString("Infinity"));
      fail();
    } catch (MalformedJsonException expected) {
-      assertEquals("Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $", expected.getMessage());
+      assertEquals("Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 (char 'I') path $", expected.getMessage());
    }
    try {
      strategy.readNumber(fromString("-Infinity"));
      fail();
    } catch (MalformedJsonException expected) {
-      assertEquals("Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $", expected.getMessage());
+      assertEquals("Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 (char '-') path $", expected.getMessage());
    }
  }

--- a/gson/src/test/java/com/google/gson/functional/ArrayTest.java
+++ b/gson/src/test/java/com/google/gson/functional/ArrayTest.java
@ -186,7 +186,7 @@ public class ArrayTest extends TestCase {
  }

  public void testArrayOfPrimitivesAsObjectsDeserialization() throws Exception {
-    String json = "[1,'abc',0.3,1.1,5]";
+    String json = "[1,\"abc\",0.3,1.1,5]";
    Object[] objs = gson.fromJson(json, Object[].class);
    assertEquals(1, ((Number)objs[0]).intValue());
    assertEquals("abc", objs[1]);
@ -249,8 +249,8 @@ public class ArrayTest extends TestCase {
   * Regression tests for Issue 272
   */
  public void testMultidimenstionalArraysDeserialization() {
-    String json = "[['3m Co','71.72','0.02','0.03','4/2 12:00am','Manufacturing'],"
-      + "['Alcoa Inc','29.01','0.42','1.47','4/1 12:00am','Manufacturing']]";
+    String json = "[[\"3m Co\",\"71.72\",\"0.02\",\"0.03\",\"4/2 12:00am\",\"Manufacturing\"],"
+      + "[\"Alcoa Inc\",\"29.01\",\"0.42\",\"1.47\",\"4/1 12:00am\",\"Manufacturing\"]]";
    String[][] items = gson.fromJson(json, String[][].class);
    assertEquals("3m Co", items[0][0]);
    assertEquals("Manufacturing", items[1][5]);
--- a/gson/src/test/java/com/google/gson/functional/CollectionTest.java
+++ b/gson/src/test/java/com/google/gson/functional/CollectionTest.java
@ -101,7 +101,7 @@ public class CollectionTest extends TestCase {
  }

  public void testLinkedListDeserialization() {
-    String json = "['a1','a2']";
+    String json = "[\"a1\",\"a2\"]";
    Type linkedListType = new TypeToken<LinkedList<String>>() {}.getType();
    List<String> list = gson.fromJson(json, linkedListType);
    assertEquals("a1", list.get(0));
@ -119,7 +119,7 @@ public class CollectionTest extends TestCase {
  }

  public void testQueueDeserialization() {
-    String json = "['a1','a2']";
+    String json = "[\"a1\",\"a2\"]";
    Type queueType = new TypeToken<Queue<String>>() {}.getType();
    Queue<String> queue = gson.fromJson(json, queueType);
    assertEquals("a1", queue.element());
@ -385,7 +385,7 @@ public class CollectionTest extends TestCase {
    assertTrue(json.contains("2"));
  }
  public void testSetDeserialization() {
-    String json = "[{value:1},{value:2}]";
+    String json = "[{\"value\":1},{\"value\":2}]";
    Type type = new TypeToken<Set<Entry>>() {}.getType();
    Set<Entry> set = gson.fromJson(json, type);
    assertEquals(2, set.size());
--- a/gson/src/test/java/com/google/gson/functional/ConcurrencyTest.java
+++ b/gson/src/test/java/com/google/gson/functional/ConcurrencyTest.java
@ -56,7 +56,7 @@ public class ConcurrencyTest extends TestCase {
   */
  public void testSingleThreadDeserialization() { 
    for (int i = 0; i < 10; i++) { 
-      gson.fromJson("{'a':'hello','b':'world','i':1}", MyObject.class); 
+      gson.fromJson("{\"a\":\"hello\",\"b\":\"world\",\"i\":1}", MyObject.class);
    } 
  } 

@ -106,7 +106,7 @@ public class ConcurrencyTest extends TestCase {
          try {
            startLatch.await();
            for (int i = 0; i < 10; i++) {
-              gson.fromJson("{'a':'hello','b':'world','i':1}", MyObject.class); 
+              gson.fromJson("{\"a\":\"hello\",\"b\":\"world\",\"i\":1}", MyObject.class);
            }
          } catch (Throwable t) {
            failed.set(true);
--- a/gson/src/test/java/com/google/gson/functional/CustomDeserializerTest.java
+++ b/gson/src/test/java/com/google/gson/functional/CustomDeserializerTest.java
@ -112,12 +112,11 @@ public class CustomDeserializerTest extends TestCase {

  public void testJsonTypeFieldBasedDeserialization() {
    String json = "{field1:'abc',field2:'def',__type__:'SUB_TYPE1'}";
-    Gson gson = new GsonBuilder().registerTypeAdapter(MyBase.class, new JsonDeserializer<MyBase>() {
-      @Override public MyBase deserialize(JsonElement json, Type pojoType,
-          JsonDeserializationContext context) throws JsonParseException {
-        String type = json.getAsJsonObject().get(MyBase.TYPE_ACCESS).getAsString();
-        return context.deserialize(json, SubTypes.valueOf(type).getSubclass());
-      }
+    Gson gson = new GsonBuilder()
+            .setLenient()
+            .registerTypeAdapter(MyBase.class, (JsonDeserializer<MyBase>) (json1, pojoType, context) -> {
+      String type = json1.getAsJsonObject().get(MyBase.TYPE_ACCESS).getAsString();
+      return context.deserialize(json1, SubTypes.valueOf(type).getSubclass());
    }).create();
    SubType1 target = (SubType1) gson.fromJson(json, MyBase.class);
    assertEquals("abc", target.field1);
@ -150,13 +149,8 @@ public class CustomDeserializerTest extends TestCase {

  public void testCustomDeserializerReturnsNullForTopLevelObject() {
    Gson gson = new GsonBuilder()
-      .registerTypeAdapter(Base.class, new JsonDeserializer<Base>() {
-        @Override
-        public Base deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
-            throws JsonParseException {
-          return null;
-        }
-      }).create();
+            .setLenient()
+            .registerTypeAdapter(Base.class, (JsonDeserializer<Base>) (json, typeOfT, context) -> null).create();
    String json = "{baseName:'Base',subName:'SubRevised'}";
    Base target = gson.fromJson(json, Base.class);
    assertNull(target);
@ -164,13 +158,8 @@ public class CustomDeserializerTest extends TestCase {

  public void testCustomDeserializerReturnsNull() {
    Gson gson = new GsonBuilder()
-      .registerTypeAdapter(Base.class, new JsonDeserializer<Base>() {
-        @Override
-        public Base deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
-            throws JsonParseException {
-          return null;
-        }
-      }).create();
+            .setLenient()
+            .registerTypeAdapter(Base.class, (JsonDeserializer<Base>) (json, typeOfT, context) -> null).create();
    String json = "{base:{baseName:'Base',subName:'SubRevised'}}";
    ClassWithBaseField target = gson.fromJson(json, ClassWithBaseField.class);
    assertNull(target.base);
@ -178,13 +167,8 @@ public class CustomDeserializerTest extends TestCase {

  public void testCustomDeserializerReturnsNullForArrayElements() {
    Gson gson = new GsonBuilder()
-      .registerTypeAdapter(Base.class, new JsonDeserializer<Base>() {
-        @Override
-        public Base deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
-            throws JsonParseException {
-          return null;
-        }
-      }).create();
+            .setLenient()
+            .registerTypeAdapter(Base.class, (JsonDeserializer<Base>) (json, typeOfT, context) -> null).create();
    String json = "[{baseName:'Base'},{baseName:'Base'}]";
    Base[] target = gson.fromJson(json, Base[].class);
    assertNull(target[0]);
@ -193,13 +177,8 @@ public class CustomDeserializerTest extends TestCase {

  public void testCustomDeserializerReturnsNullForArrayElementsForArrayField() {
    Gson gson = new GsonBuilder()
-      .registerTypeAdapter(Base.class, new JsonDeserializer<Base>() {
-        @Override
-        public Base deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
-            throws JsonParseException {
-          return null;
-        }
-      }).create();
+            .setLenient()
+            .registerTypeAdapter(Base.class, (JsonDeserializer<Base>) (json, typeOfT, context) -> null).create();
    String json = "{bases:[{baseName:'Base'},{baseName:'Base'}]}";
    ClassWithBaseArray target = gson.fromJson(json, ClassWithBaseArray.class);
    assertNull(target.bases[0]);
--- a/gson/src/test/java/com/google/gson/functional/CustomTypeAdaptersTest.java
+++ b/gson/src/test/java/com/google/gson/functional/CustomTypeAdaptersTest.java
@ -264,7 +264,7 @@ public class CustomTypeAdaptersTest extends TestCase {
      }
    });
    Gson gson = gsonBuilder.create();
-    String json = "'0123456789'";
+    String json = "\"0123456789\"";
    byte[] actual = gson.fromJson(json, byte[].class);
    byte[] expected = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
    for (int i = 0; i < actual.length; ++i) {
@ -338,7 +338,7 @@ public class CustomTypeAdaptersTest extends TestCase {
      .registerTypeAdapter(StringHolder.class, new StringHolderTypeAdapter())
      .create();
    Type setType = new TypeToken<Set<StringHolder>>() {}.getType();
-    Set<StringHolder> setOfHolders = gson.fromJson("['Jacob:Tomaw']", setType);
+    Set<StringHolder> setOfHolders = gson.fromJson("[\"Jacob:Tomaw\"]", setType);
    assertEquals(1, setOfHolders.size());
    StringHolder foo = setOfHolders.iterator().next();
    assertEquals("Jacob", foo.part1);
@ -376,7 +376,7 @@ public class CustomTypeAdaptersTest extends TestCase {
      .registerTypeAdapter(StringHolder.class, new StringHolderTypeAdapter())
      .create();
    Type mapType = new TypeToken<Map<String, StringHolder>>() {}.getType();
-    Map<String, StringHolder> mapOfFoo = gson.fromJson("{'foo':'Jacob:Tomaw'}", mapType);
+    Map<String, StringHolder> mapOfFoo = gson.fromJson("{\"foo\":\"Jacob:Tomaw\"}", mapType);
    assertEquals(1, mapOfFoo.size());
    StringHolder foo = mapOfFoo.get("foo");
    assertEquals("Jacob", foo.part1);
@ -394,8 +394,9 @@ public class CustomTypeAdaptersTest extends TestCase {

  public void testEnsureCustomDeserializerNotInvokedForNullValues() {
    Gson gson = new GsonBuilder()
-        .registerTypeAdapter(DataHolder.class, new DataHolderDeserializer())
-        .create();
+            .setLenient()
+            .registerTypeAdapter(DataHolder.class, new DataHolderDeserializer())
+            .create();
    String json = "{wrappedData:null}";
    DataHolderWrapper actual = gson.fromJson(json, DataHolderWrapper.class);
    assertNull(actual.wrappedData);
@ -404,8 +405,8 @@ public class CustomTypeAdaptersTest extends TestCase {
  // Test created from Issue 352
  public void testRegisterHierarchyAdapterForDate() {
    Gson gson = new GsonBuilder()
-        .registerTypeHierarchyAdapter(Date.class, new DateTypeAdapter())
-        .create();
+            .registerTypeHierarchyAdapter(Date.class, new DateTypeAdapter())
+            .create();
    assertEquals("0", gson.toJson(new Date(0)));
    assertEquals("0", gson.toJson(new java.sql.Date(0)));
    assertEquals(new Date(0), gson.fromJson("0", Date.class));
--- a/gson/src/test/java/com/google/gson/functional/DefaultTypeAdaptersTest.java
+++ b/gson/src/test/java/com/google/gson/functional/DefaultTypeAdaptersTest.java
@ -104,7 +104,7 @@ public class DefaultTypeAdaptersTest extends TestCase {
    } catch (UnsupportedOperationException expected) {
    }
    // Override with a custom type adapter for class.
-    gson = new GsonBuilder().registerTypeAdapter(Class.class, new MyClassTypeAdapter()).create();
+    gson = new GsonBuilder().setLenient().registerTypeAdapter(Class.class, new MyClassTypeAdapter()).create();
    assertEquals(String.class, gson.fromJson("java.lang.String", Class.class));
  }

@ -410,7 +410,7 @@ public class DefaultTypeAdaptersTest extends TestCase {
  }

  public void testDefaultCalendarDeserialization() throws Exception {
-    Gson gson = new GsonBuilder().create();
+    Gson gson = new Gson();
    String json = "{year:2009,month:2,dayOfMonth:11,hourOfDay:14,minute:29,second:23}";
    Calendar cal = gson.fromJson(json, Calendar.class);
    assertEquals(2009, cal.get(Calendar.YEAR));
@ -434,7 +434,7 @@ public class DefaultTypeAdaptersTest extends TestCase {
  }

  public void testDefaultGregorianCalendarDeserialization() throws Exception {
-    Gson gson = new GsonBuilder().create();
+    Gson gson = new Gson();
    String json = "{year:2009,month:2,dayOfMonth:11,hourOfDay:14,minute:29,second:23}";
    GregorianCalendar cal = gson.fromJson(json, GregorianCalendar.class);
    assertEquals(2009, cal.get(Calendar.YEAR));
--- a/gson/src/test/java/com/google/gson/functional/EnumWithObfuscatedTest.java
+++ b/gson/src/test/java/com/google/gson/functional/EnumWithObfuscatedTest.java
@ -1,58 +0,0 @@
-/*
- * 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.gson.functional;
-
-import com.google.gson.Gson;
-import com.google.gson.annotations.SerializedName;
-
-import junit.framework.TestCase;
-
-/**
- * Functional tests for enums with Proguard.
- *
- * @author Young Cha
- */
-public class EnumWithObfuscatedTest extends TestCase {
-  private Gson gson;
-
-  @Override
-  protected void setUp() throws Exception {
-    super.setUp();
-    gson = new Gson();
-  }
-
-  public enum Gender {
-    @SerializedName("MAIL")
-    MALE,
-
-    @SerializedName("FEMAIL")
-    FEMALE
-  }
-
-  public void testEnumClassWithObfuscated() {
-    for (Gender enumConstant: Gender.class.getEnumConstants()) {
-      try {
-        Gender.class.getField(enumConstant.name());
-        fail("Enum is not obfuscated");
-      } catch (NoSuchFieldException ignore) {
-      }
-    }
-
-    assertEquals(Gender.MALE, gson.fromJson("\"MAIL\"", Gender.class));
-    assertEquals("\"MAIL\"", gson.toJson(Gender.MALE, Gender.class));
-  }
-}
--- a/gson/src/test/java/com/google/gson/functional/ExposeFieldsTest.java
+++ b/gson/src/test/java/com/google/gson/functional/ExposeFieldsTest.java
@ -38,6 +38,7 @@ public class ExposeFieldsTest extends TestCase {
  protected void setUp() throws Exception {
    super.setUp();
    gson = new GsonBuilder()
+        .setLenient()
        .excludeFieldsWithoutExposeAnnotation()
        .registerTypeAdapter(SomeInterface.class, new SomeInterfaceInstanceCreator())
        .create();
--- a/gson/src/test/java/com/google/gson/functional/InstanceCreatorTest.java
+++ b/gson/src/test/java/com/google/gson/functional/InstanceCreatorTest.java
@ -42,12 +42,9 @@ public class InstanceCreatorTest extends TestCase {

  public void testInstanceCreatorReturnsBaseType() {
    Gson gson = new GsonBuilder()
-      .registerTypeAdapter(Base.class, new InstanceCreator<Base>() {
-        @Override public Base createInstance(Type type) {
-         return new Base();
-       }
-      })
-      .create();
+            .setLenient()
+            .registerTypeAdapter(Base.class, (InstanceCreator<Base>) type -> new Base())
+            .create();
    String json = "{baseName:'BaseRevised',subName:'Sub'}";
    Base base = gson.fromJson(json, Base.class);
    assertEquals("BaseRevised", base.baseName);
@ -55,12 +52,9 @@ public class InstanceCreatorTest extends TestCase {

  public void testInstanceCreatorReturnsSubTypeForTopLevelObject() {
    Gson gson = new GsonBuilder()
-    .registerTypeAdapter(Base.class, new InstanceCreator<Base>() {
-      @Override public Base createInstance(Type type) {
-        return new Sub();
-      }
-    })
-    .create();
+            .setLenient()
+            .registerTypeAdapter(Base.class, (InstanceCreator<Base>) type -> new Sub())
+            .create();

    String json = "{baseName:'Base',subName:'SubRevised'}";
    Base base = gson.fromJson(json, Base.class);
@ -73,12 +67,9 @@ public class InstanceCreatorTest extends TestCase {

  public void testInstanceCreatorReturnsSubTypeForField() {
    Gson gson = new GsonBuilder()
-    .registerTypeAdapter(Base.class, new InstanceCreator<Base>() {
-      @Override public Base createInstance(Type type) {
-        return new Sub();
-      }
-    })
-    .create();
+            .setLenient()
+            .registerTypeAdapter(Base.class, (InstanceCreator<Base>) type -> new Sub())
+            .create();
    String json = "{base:{baseName:'Base',subName:'SubRevised'}}";
    ClassWithBaseField target = gson.fromJson(json, ClassWithBaseField.class);
    assertTrue(target.base instanceof Sub);
--- a/gson/src/test/java/com/google/gson/functional/InternationalizationTest.java
+++ b/gson/src/test/java/com/google/gson/functional/InternationalizationTest.java
@ -65,7 +65,7 @@ public class InternationalizationTest extends TestCase {
  }

  public void testStringsWithUnicodeChineseCharactersEscapedDeserialization() throws Exception {
-    String actual = gson.fromJson("'\\u597d\\u597d\\u597d'", String.class);
+    String actual = gson.fromJson("\"\\u597d\\u597d\\u597d\"", String.class);
    assertEquals("\u597d\u597d\u597d", actual);
  }
 }
--- a/gson/src/test/java/com/google/gson/functional/JavaUtilConcurrentAtomicTest.java
+++ b/gson/src/test/java/com/google/gson/functional/JavaUtilConcurrentAtomicTest.java
@ -65,7 +65,7 @@ public class JavaUtilConcurrentAtomicTest extends TestCase {
    Gson gson = new GsonBuilder()
        .setLongSerializationPolicy(LongSerializationPolicy.STRING)
        .create();
-    AtomicLongHolder target = gson.fromJson("{'value':'10'}", AtomicLongHolder.class);
+    AtomicLongHolder target = gson.fromJson("{\"value\":\"10\"}", AtomicLongHolder.class);
    assertEquals(10, target.value.get());
    String json = gson.toJson(target);
    assertEquals("{\"value\":\"10\"}", json);
@ -95,7 +95,7 @@ public class JavaUtilConcurrentAtomicTest extends TestCase {
    Gson gson = new GsonBuilder()
        .setLongSerializationPolicy(LongSerializationPolicy.STRING)
        .create();
-    AtomicLongArray target = gson.fromJson("['10', '13', '14']", AtomicLongArray.class);
+    AtomicLongArray target = gson.fromJson("[\"10\", \"13\", \"14\"]", AtomicLongArray.class);
    assertEquals(3, target.length());
    assertEquals(10, target.get(0));
    assertEquals(13, target.get(1));
--- a/gson/src/test/java/com/google/gson/functional/JavaUtilTest.java
+++ b/gson/src/test/java/com/google/gson/functional/JavaUtilTest.java
@ -36,7 +36,7 @@ public class JavaUtilTest extends TestCase {
  }

  public void testCurrency() throws Exception {
-    CurrencyHolder target = gson.fromJson("{'value':'USD'}", CurrencyHolder.class);
+    CurrencyHolder target = gson.fromJson("{\"value\":\"USD\"}", CurrencyHolder.class);
    assertEquals("USD", target.value.getCurrencyCode());
    String json = gson.toJson(target);
    assertEquals("{\"value\":\"USD\"}", json);
@ -52,7 +52,7 @@ public class JavaUtilTest extends TestCase {
  }

  public void testProperties() {
-    Properties props = gson.fromJson("{'a':'v1','b':'v2'}", Properties.class);
+    Properties props = gson.fromJson("{\"a\":\"v1\",\"b\":\"v2\"}", Properties.class);
    assertEquals("v1", props.getProperty("a"));
    assertEquals("v2", props.getProperty("b"));
    String json = gson.toJson(props);
--- a/gson/src/test/java/com/google/gson/functional/JsonAdapterAnnotationOnClassesTest.java
+++ b/gson/src/test/java/com/google/gson/functional/JsonAdapterAnnotationOnClassesTest.java
@ -49,7 +49,7 @@ public final class JsonAdapterAnnotationOnClassesTest extends TestCase {
   // Also invoke the JsonAdapter javadoc sample
    json = gson.toJson(new User("Inderjeet", "Singh"));
    assertEquals("{\"name\":\"Inderjeet Singh\"}", json);
-    User user = gson.fromJson("{'name':'Joel Leitch'}", User.class);
+    User user = gson.fromJson("{\"name\":\"Joel Leitch\"}", User.class);
    assertEquals("Joel", user.firstName);
    assertEquals("Leitch", user.lastName);

@ -94,6 +94,7 @@ public final class JsonAdapterAnnotationOnClassesTest extends TestCase {
      }
    };
    Gson gson = new GsonBuilder()
+      .setLenient()
      .registerTypeAdapter(A.class, serializer)
      .create();
    String json = gson.toJson(new A("abcd"));
@ -113,6 +114,7 @@ public final class JsonAdapterAnnotationOnClassesTest extends TestCase {
      }
    };
    Gson gson = new GsonBuilder()
+      .setLenient()
      .registerTypeAdapter(A.class, deserializer)
      .create();
    String json = gson.toJson(new A("abcd"));
--- a/gson/src/test/java/com/google/gson/functional/JsonAdapterAnnotationOnFieldsTest.java
+++ b/gson/src/test/java/com/google/gson/functional/JsonAdapterAnnotationOnFieldsTest.java
@ -57,12 +57,13 @@ public final class JsonAdapterAnnotationOnFieldsTest extends TestCase {
        .create();
    String json = gson.toJson(new Computer(new User("Inderjeet Singh")));
    assertEquals("{\"user\":\"RegisteredUserAdapter\"}", json);
-    Computer computer = gson.fromJson("{'user':'Inderjeet Singh'}", Computer.class);
+    Computer computer = gson.fromJson("{\"user\":\"Inderjeet Singh\"}", Computer.class);
    assertEquals("RegisteredUserAdapter", computer.user.name);
  }

  public void testFieldAnnotationTakesPrecedenceOverRegisteredTypeAdapter() {
    Gson gson = new GsonBuilder()
+      .setLenient()
      .registerTypeAdapter(Part.class, new TypeAdapter<Part>() {
        @Override public void write(JsonWriter out, Part part) throws IOException {
          throw new AssertionError();
--- a/gson/src/test/java/com/google/gson/functional/JsonParserTest.java
+++ b/gson/src/test/java/com/google/gson/functional/JsonParserTest.java
@ -16,13 +16,7 @@

 package com.google.gson.functional;

-import com.google.gson.Gson;
-import com.google.gson.JsonArray;
-import com.google.gson.JsonObject;
-import com.google.gson.JsonParseException;
-import com.google.gson.JsonParser;
-import com.google.gson.JsonPrimitive;
-import com.google.gson.JsonSyntaxException;
+import com.google.gson.*;
 import com.google.gson.common.TestTypes.BagOfPrimitives;
 import com.google.gson.common.TestTypes.Nested;
 import com.google.gson.reflect.TypeToken;
@ -123,9 +117,9 @@ public class JsonParserTest extends TestCase {

  public void testExtraCommasInArrays() {
    Type type = new TypeToken<List<String>>() {}.getType();
-    assertEquals(Arrays.asList("a", null, "b", null, null), gson.fromJson("[a,,b,,]", type));
-    assertEquals(Arrays.asList(null, null), gson.fromJson("[,]", type));
-    assertEquals(Arrays.asList("a", null), gson.fromJson("[a,]", type));
+    assertEquals(Arrays.asList("a", "b"), gson.fromJson("[a,,b,,]", type));
+    assertEquals(Arrays.asList(), gson.fromJson("[,]", type));
+    assertEquals(Arrays.asList("a"), gson.fromJson("[a,]", type));
  }

  public void testExtraCommasInMaps() {
--- a/gson/src/test/java/com/google/gson/functional/LeniencyTest.java
+++ b/gson/src/test/java/com/google/gson/functional/LeniencyTest.java
@ -33,7 +33,7 @@ public class LeniencyTest extends TestCase {
  @Override
  protected void setUp() throws Exception {
    super.setUp();
-    gson = new GsonBuilder().setLenient().create();
+    gson = new Gson();
  }

  public void testLenientFromJson() {
--- a/gson/src/test/java/com/google/gson/functional/MapAsArrayTypeAdapterTest.java
+++ b/gson/src/test/java/com/google/gson/functional/MapAsArrayTypeAdapterTest.java
@ -106,7 +106,7 @@ public class MapAsArrayTypeAdapterTest extends TestCase {
  }

  public void testMapWithTypeVariableDeserialization() {
-    Gson gson = new GsonBuilder().enableComplexMapKeySerialization().create();
+    Gson gson = new GsonBuilder().setLenient().enableComplexMapKeySerialization().create();
    String json = "{map:[[{x:2,y:3},{x:4,y:5}]]}";
    Type type = new TypeToken<PointWithProperty<Point>>(){}.getType();
    PointWithProperty<Point> map = gson.fromJson(json, type);
--- a/gson/src/test/java/com/google/gson/functional/MapTest.java
+++ b/gson/src/test/java/com/google/gson/functional/MapTest.java
@ -155,7 +155,7 @@ public class MapTest extends TestCase {
    assertEquals(123, map.get("null").intValue());
    assertNull(map.get(null));

-    map = gson.fromJson("{null:123}", typeOfMap);
+    map = gson.fromJson("{'null':123}", typeOfMap);
    assertEquals(1, map.size());
    assertEquals(123, map.get("null").intValue());
    assertNull(map.get(null));
--- a/gson/src/test/java/com/google/gson/functional/NullObjectAndFieldTest.java
+++ b/gson/src/test/java/com/google/gson/functional/NullObjectAndFieldTest.java
@ -99,7 +99,7 @@ public class NullObjectAndFieldTest extends TestCase {
   */
  public void testNullWrappedPrimitiveMemberDeserialization() {
    Gson gson = gsonBuilder.create();
-    String json = "{'value':null}";
+    String json = "{\"value\":null}";
    ClassWithNullWrappedPrimitive target = gson.fromJson(json, ClassWithNullWrappedPrimitive.class);
    assertNull(target.value);
  }
@ -223,12 +223,8 @@ public class NullObjectAndFieldTest extends TestCase {

  public void testCustomTypeAdapterPassesNullDesrialization() {
    Gson gson = new GsonBuilder()
-        .registerTypeAdapter(ObjectWithField.class, new JsonDeserializer<ObjectWithField>() {
-          @Override public ObjectWithField deserialize(JsonElement json, Type type,
-              JsonDeserializationContext context) {
-            return context.deserialize(null, type);
-          }
-        }).create();
+            .setLenient()
+            .registerTypeAdapter(ObjectWithField.class, (JsonDeserializer<ObjectWithField>) (json, type, context) -> context.deserialize(null, type)).create();
    String json = "{value:'value1'}";
    ObjectWithField target = gson.fromJson(json, ObjectWithField.class);
    assertNull(target);
--- a/gson/src/test/java/com/google/gson/functional/ObjectTest.java
+++ b/gson/src/test/java/com/google/gson/functional/ObjectTest.java
@ -346,7 +346,7 @@ public class ObjectTest extends TestCase {
        return p.new Child();
      }
    }).create();
-    String json = "{'value2':3}";
+    String json = "{\"value2\":3}";
    Parent.Child c = gson.fromJson(json, Parent.Child.class);
    assertEquals(3, c.value2);
  }
--- a/gson/src/test/java/com/google/gson/functional/PrimitiveCharacterTest.java
+++ b/gson/src/test/java/com/google/gson/functional/PrimitiveCharacterTest.java
@ -16,10 +16,9 @@

 package com.google.gson.functional;

+import com.google.gson.*;
 import junit.framework.TestCase;

-import com.google.gson.Gson;
-
 /**
 * Functional tests for Java Character values.
 *
--- a/gson/src/test/java/com/google/gson/functional/PrimitiveTest.java
+++ b/gson/src/test/java/com/google/gson/functional/PrimitiveTest.java
@ -18,11 +18,7 @@ package com.google.gson.functional;

 import static org.junit.Assert.assertArrayEquals;

-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-import com.google.gson.JsonPrimitive;
-import com.google.gson.JsonSyntaxException;
-import com.google.gson.LongSerializationPolicy;
+import com.google.gson.*;
 import com.google.gson.internal.LazilyParsedNumber;
 import com.google.gson.reflect.TypeToken;
 import java.io.Serializable;
@ -95,7 +91,7 @@ public class PrimitiveTest extends TestCase {
      gson.fromJson("2147483648", byte.class);
      fail();
    } catch (JsonSyntaxException e) {
-      assertEquals("java.lang.NumberFormatException: Expected an int but was 2147483648 at line 1 column 11 path $", e.getMessage());
+      assertEquals("java.lang.NumberFormatException: Expected an int but was 2147483648 at line 1 column 11 (char '\0') path $", e.getMessage());
    }
  }

@ -133,7 +129,7 @@ public class PrimitiveTest extends TestCase {
      gson.fromJson("2147483648", short.class);
      fail();
    } catch (JsonSyntaxException e) {
-      assertEquals("java.lang.NumberFormatException: Expected an int but was 2147483648 at line 1 column 11 path $", e.getMessage());
+      assertEquals("java.lang.NumberFormatException: Expected an int but was 2147483648 at line 1 column 11 (char '\0') path $", e.getMessage());
    }
  }

@ -435,7 +431,7 @@ public class PrimitiveTest extends TestCase {
  }

  public void testDoubleNaNSerialization() {
-    Gson gson = new GsonBuilder().serializeSpecialFloatingPointValues().create();
+    Gson gson = new GsonBuilder().setLenient().serializeSpecialFloatingPointValues().create();
    double nan = Double.NaN;
    assertEquals("NaN", gson.toJson(nan));
    assertEquals("NaN", gson.toJson(Double.NaN));
@ -461,7 +457,7 @@ public class PrimitiveTest extends TestCase {
  }

  public void testFloatNaNSerialization() {
-    Gson gson = new GsonBuilder().serializeSpecialFloatingPointValues().create();
+    Gson gson = new GsonBuilder().setLenient().serializeSpecialFloatingPointValues().create();
    float nan = Float.NaN;
    assertEquals("NaN", gson.toJson(nan));
    assertEquals("NaN", gson.toJson(Float.NaN));
@ -495,7 +491,7 @@ public class PrimitiveTest extends TestCase {
  }

  public void testDoubleInfinitySerialization() {
-    Gson gson = new GsonBuilder().serializeSpecialFloatingPointValues().create();
+    Gson gson = new GsonBuilder().setLenient().serializeSpecialFloatingPointValues().create();
    double infinity = Double.POSITIVE_INFINITY;
    assertEquals("Infinity", gson.toJson(infinity));
    assertEquals("Infinity", gson.toJson(Double.POSITIVE_INFINITY));
@ -521,7 +517,7 @@ public class PrimitiveTest extends TestCase {
  }

  public void testFloatInfinitySerialization() {
-    Gson gson = new GsonBuilder().serializeSpecialFloatingPointValues().create();
+    Gson gson = new GsonBuilder().setLenient().serializeSpecialFloatingPointValues().create();
    float infinity = Float.POSITIVE_INFINITY;
    assertEquals("Infinity", gson.toJson(infinity));
    assertEquals("Infinity", gson.toJson(Float.POSITIVE_INFINITY));
@ -555,7 +551,7 @@ public class PrimitiveTest extends TestCase {
  }

  public void testNegativeInfinitySerialization() {
-    Gson gson = new GsonBuilder().serializeSpecialFloatingPointValues().create();
+    Gson gson = new GsonBuilder().setLenient().serializeSpecialFloatingPointValues().create();
    double negativeInfinity = Double.NEGATIVE_INFINITY;
    assertEquals("-Infinity", gson.toJson(negativeInfinity));
    assertEquals("-Infinity", gson.toJson(Double.NEGATIVE_INFINITY));
@ -581,7 +577,7 @@ public class PrimitiveTest extends TestCase {
  }

  public void testNegativeInfinityFloatSerialization() {
-    Gson gson = new GsonBuilder().serializeSpecialFloatingPointValues().create();
+    Gson gson = new GsonBuilder().setLenient().serializeSpecialFloatingPointValues().create();
    float negativeInfinity = Float.NEGATIVE_INFINITY;
    assertEquals("-Infinity", gson.toJson(negativeInfinity));
    assertEquals("-Infinity", gson.toJson(Float.NEGATIVE_INFINITY));
@ -633,9 +629,9 @@ public class PrimitiveTest extends TestCase {

    String value = "String Blah Blah Blah...1, 2, 3";
    try {
-      gson.fromJson(value, String.class);
+      new Gson().fromJson(value, String.class);
      fail();
-    } catch (JsonSyntaxException expected) { }
+    } catch (JsonIOException expected) { }
  }

  public void testHtmlCharacterSerialization() throws Exception {
--- a/gson/src/test/java/com/google/gson/functional/SecurityTest.java
+++ b/gson/src/test/java/com/google/gson/functional/SecurityTest.java
@ -38,7 +38,7 @@ public class SecurityTest extends TestCase {
  @Override
  protected void setUp() throws Exception {
    super.setUp();
-    gsonBuilder = new GsonBuilder();
+    gsonBuilder = new GsonBuilder().setLenient();
  }

  public void testNonExecutableJsonSerialization() {
--- a/gson/src/test/java/com/google/gson/functional/StreamingTypeAdaptersTest.java
+++ b/gson/src/test/java/com/google/gson/functional/StreamingTypeAdaptersTest.java
@ -159,7 +159,7 @@ public final class StreamingTypeAdaptersTest extends TestCase {
        out.value(person.name + "," + person.age);
      }
    };
-    Gson gson = new GsonBuilder().registerTypeAdapter(
+    Gson gson = new GsonBuilder().setLenient().registerTypeAdapter(
        Person.class, typeAdapter).create();
    Truck truck = new Truck();
    truck.horsePower = 1.0D;
@ -175,7 +175,7 @@ public final class StreamingTypeAdaptersTest extends TestCase {
      gson.fromJson(json, Truck.class);
      fail();
    } catch (JsonSyntaxException expected) {}
-    gson = new GsonBuilder().registerTypeAdapter(Person.class, typeAdapter.nullSafe()).create();
+    gson = new GsonBuilder().setLenient().registerTypeAdapter(Person.class, typeAdapter.nullSafe()).create();
    assertEquals("{\"horsePower\":1.0,\"passengers\":[null,\"jesse,30\"]}",
        gson.toJson(truck, Truck.class));
    truck = gson.fromJson(json, Truck.class);
--- a/gson/src/test/java/com/google/gson/functional/TreeTypeAdaptersTest.java
+++ b/gson/src/test/java/com/google/gson/functional/TreeTypeAdaptersTest.java
@ -54,6 +54,7 @@ public class TreeTypeAdaptersTest extends TestCase {
  @Override
  protected void setUp() {
    gson = new GsonBuilder()
+        .setLenient()
        .registerTypeAdapter(Id.class, new IdTreeTypeAdapter())
        .create();
    course = new Course<>(COURSE_ID, 4,
--- a/gson/src/test/java/com/google/gson/functional/TypeAdapterPrecedenceTest.java
+++ b/gson/src/test/java/com/google/gson/functional/TypeAdapterPrecedenceTest.java
@ -34,6 +34,7 @@ import junit.framework.TestCase;
 public final class TypeAdapterPrecedenceTest extends TestCase {
  public void testNonstreamingFollowedByNonstreaming() {
    Gson gson = new GsonBuilder()
+        .setLenient()
        .registerTypeAdapter(Foo.class, newSerializer("serializer 1"))
        .registerTypeAdapter(Foo.class, newSerializer("serializer 2"))
        .registerTypeAdapter(Foo.class, newDeserializer("deserializer 1"))
@ -45,6 +46,7 @@ public final class TypeAdapterPrecedenceTest extends TestCase {

  public void testStreamingFollowedByStreaming() {
    Gson gson = new GsonBuilder()
+        .setLenient()
        .registerTypeAdapter(Foo.class, newTypeAdapter("type adapter 1"))
        .registerTypeAdapter(Foo.class, newTypeAdapter("type adapter 2"))
        .create();
@ -54,6 +56,7 @@ public final class TypeAdapterPrecedenceTest extends TestCase {

  public void testSerializeNonstreamingTypeAdapterFollowedByStreamingTypeAdapter() {
    Gson gson = new GsonBuilder()
+        .setLenient()
        .registerTypeAdapter(Foo.class, newSerializer("serializer"))
        .registerTypeAdapter(Foo.class, newDeserializer("deserializer"))
        .registerTypeAdapter(Foo.class, newTypeAdapter("type adapter"))
@ -64,6 +67,7 @@ public final class TypeAdapterPrecedenceTest extends TestCase {

  public void testStreamingFollowedByNonstreaming() {
    Gson gson = new GsonBuilder()
+        .setLenient()
        .registerTypeAdapter(Foo.class, newTypeAdapter("type adapter"))
        .registerTypeAdapter(Foo.class, newSerializer("serializer"))
        .registerTypeAdapter(Foo.class, newDeserializer("deserializer"))
@ -74,6 +78,7 @@ public final class TypeAdapterPrecedenceTest extends TestCase {

  public void testStreamingHierarchicalFollowedByNonstreaming() {
    Gson gson = new GsonBuilder()
+        .setLenient()
        .registerTypeHierarchyAdapter(Foo.class, newTypeAdapter("type adapter"))
        .registerTypeAdapter(Foo.class, newSerializer("serializer"))
        .registerTypeAdapter(Foo.class, newDeserializer("deserializer"))
@ -89,11 +94,12 @@ public final class TypeAdapterPrecedenceTest extends TestCase {
        .registerTypeHierarchyAdapter(Foo.class, newDeserializer("deserializer"))
        .create();
    assertEquals("\"foo via type adapter\"", gson.toJson(new Foo("foo")));
-    assertEquals("foo via type adapter", gson.fromJson("foo", Foo.class).name);
+    assertEquals("foo via type adapter", gson.fromJson("\"foo\"", Foo.class).name);
  }

  public void testStreamingHierarchicalFollowedByNonstreamingHierarchical() {
    Gson gson = new GsonBuilder()
+        .setLenient()
        .registerTypeHierarchyAdapter(Foo.class, newSerializer("serializer"))
        .registerTypeHierarchyAdapter(Foo.class, newDeserializer("deserializer"))
        .registerTypeHierarchyAdapter(Foo.class, newTypeAdapter("type adapter"))
@ -104,6 +110,7 @@ public final class TypeAdapterPrecedenceTest extends TestCase {

  public void testNonstreamingHierarchicalFollowedByNonstreaming() {
    Gson gson = new GsonBuilder()
+        .setLenient()
        .registerTypeHierarchyAdapter(Foo.class, newSerializer("hierarchical"))
        .registerTypeHierarchyAdapter(Foo.class, newDeserializer("hierarchical"))
        .registerTypeAdapter(Foo.class, newSerializer("non hierarchical"))
--- a/gson/src/test/java/com/google/gson/internal/sql/SqlTypesGsonTest.java
+++ b/gson/src/test/java/com/google/gson/internal/sql/SqlTypesGsonTest.java
@ -52,7 +52,7 @@ public class SqlTypesGsonTest extends TestCase {
  }

  public void testDefaultSqlDateDeserialization() {
-    String json = "'Dec 3, 2009'";
+    String json = "\"Dec 3, 2009\"";
    java.sql.Date extracted = gson.fromJson(json, java.sql.Date.class);
    DefaultTypeAdaptersTest.assertEqualsDate(extracted, 2009, 11, 3);
  }
@ -82,7 +82,7 @@ public class SqlTypesGsonTest extends TestCase {
  }

  public void testDefaultSqlTimeDeserialization() {
-    String json = "'1:18:02 PM'";
+    String json = "\"1:18:02 PM\"";
    Time extracted = gson.fromJson(json, Time.class);
    DefaultTypeAdaptersTest.assertEqualsTime(extracted, 13, 18, 2);
  }
@ -98,7 +98,7 @@ public class SqlTypesGsonTest extends TestCase {
  }

  public void testDefaultSqlTimestampDeserialization() {
-    String json = "'Dec 3, 2009 1:18:02 PM'";
+    String json = "\"Dec 3, 2009 1:18:02 PM\"";
    Timestamp extracted = gson.fromJson(json, Timestamp.class);
    DefaultTypeAdaptersTest.assertEqualsDate(extracted, 2009, 11, 3);
    DefaultTypeAdaptersTest.assertEqualsTime(extracted, 13, 18, 2);
--- a/gson/src/test/java/com/google/gson/jf/CommentsTest.java
+++ b/gson/src/test/java/com/google/gson/jf/CommentsTest.java
@ -14,8 +14,9 @@
 * limitations under the License.
 */

-package com.google.gson;
+package com.google.gson.jf;

+import com.google.gson.*;
 import com.google.gson.reflect.TypeToken;
 import java.util.Arrays;
 import java.util.List;
@ -39,7 +40,7 @@ public final class CommentsTest extends TestCase {
        + "  \"c\"\n"
        + "]";

-    List<String> abc = new Gson().fromJson(json, new TypeToken<List<String>>() {}.getType());
+    List<String> abc = new GsonBuilder().setLenient().create().fromJson(json, new TypeToken<List<String>>() {}.getType());
    assertEquals(Arrays.asList("a", "b", "c"), abc);
  }
 }
--- a/gson/src/test/java/com/google/gson/jf/ExtraAssert.java
+++ b/gson/src/test/java/com/google/gson/jf/ExtraAssert.java
@ -0,0 +1,28 @@
+package com.google.gson.jf;
+
+import junit.framework.*;
+
+import java.util.*;
+
+public class ExtraAssert {
+  public static <T> void assertListEquals(List<T> expecteds, List<T> actuals) {
+    TestCase.assertNotNull(expecteds);
+    TestCase.assertNotNull(actuals);
+    TestCase.assertEquals(expecteds.size(), actuals.size());
+    for (int i = 0; i < expecteds.size(); i++) {
+      TestCase.assertEquals(expecteds.get(i), actuals.get(i));
+    }
+  }
+
+  public static class StringArrayBox {
+    public String[] collection;
+  }
+
+  public static class StringListBox {
+    public List<String> collection;
+  }
+
+  public static class IntListBox {
+    public List<Integer> collection;
+  }
+}
--- a/gson/src/test/java/com/google/gson/jf/Json5Test.java
+++ b/gson/src/test/java/com/google/gson/jf/Json5Test.java
@ -0,0 +1,49 @@
+package com.google.gson.jf;
+
+import com.google.gson.*;
+import junit.framework.*;
+
+public class Json5Test extends TestCase {
+    public void testShortExample() {
+        // Taken from the official example
+        assertTrue(new Gson().fromJson("{\n" +
+                "  // comments\n" +
+                "  unquoted: 'and you can quote me on that',\n" +
+                "  singleQuotes: 'I can use \"double quotes\" here',\n" +
+                "  lineBreaks: \"Look, Mom! \\\n" +
+                "No \\\\n's!\",\n" +
+                "  hexadecimal: 0xdecaf,\n" +
+                "  leadingDecimalPoint: .8675309, andTrailing: 8675309.,\n" +
+                "  positiveSign: +1,\n" +
+                "  trailingComma: 'in objects', andIn: ['arrays',],\n" +
+                "  \"backwardsCompatible\": \"with JSON\",\n" +
+                "}", ExampleModel.class).isDefault());
+    }
+
+    public static class ExampleModel {
+        public String unquoted;
+        public String singleQuotes;
+        public String lineBreaks;
+        public Integer hexadecimal;
+        public Double leadingDecimalPoint;
+        public Double andTrailing;
+        public Integer positiveSign;
+        public String trailingComma;
+        public String[] andIn;
+        public String backwardsCompatible;
+
+        public boolean isDefault() {
+            return unquoted.equals("and you can quote me on that")
+                    && singleQuotes.equals("I can use \"double quotes\" here")
+                    && lineBreaks.equals("Look, Mom!\nNo \\n's!")
+                    && hexadecimal.equals(0xdecaf)
+                    && leadingDecimalPoint.equals(.8675309)
+                    && andTrailing.equals(8675309.)
+                    && positiveSign.equals(1)
+                    && trailingComma.equals("in objects")
+                    && andIn.length == 1 && andIn[0].equals("arrays")
+                    && backwardsCompatible.equals("with JSON");
+
+        }
+    }
+}
--- a/gson/src/test/java/com/google/gson/jf/LenientCollectionCommaTest.java
+++ b/gson/src/test/java/com/google/gson/jf/LenientCollectionCommaTest.java
@ -0,0 +1,22 @@
+package com.google.gson.jf;
+
+import com.google.gson.*;
+import junit.framework.TestCase;
+import java.util.*;
+
+import static com.google.gson.jf.ExtraAssert.*;
+
+public class LenientCollectionCommaTest extends TestCase {
+  private Gson lenient;
+  private static final String json = "{\"collection\": [1, 2,, 3, , , 4, 5,]}";
+
+  @Override
+  protected void setUp() throws Exception {
+    super.setUp();
+    lenient = new GsonBuilder().setLenient().create();
+  }
+
+  public void testElementSkipping() {
+    assertListEquals(List.of(1, 2, 3, 4, 5), lenient.fromJson(json, IntListBox.class).collection);
+  }
+}
--- a/gson/src/test/java/com/google/gson/jf/LenientCollectionTest.java
+++ b/gson/src/test/java/com/google/gson/jf/LenientCollectionTest.java
@ -0,0 +1,45 @@
+package com.google.gson.jf;
+
+import com.google.gson.*;
+import junit.framework.TestCase;
+import java.util.*;
+
+import static org.junit.Assert.*;
+import static com.google.gson.jf.ExtraAssert.*;
+
+public class LenientCollectionTest extends TestCase {
+  private Gson lenient;
+  private Gson strict;
+  private static final String json = "{\"collection\": \"example\"}";
+
+  @Override
+  protected void setUp() throws Exception {
+    super.setUp();
+    lenient = new GsonBuilder().setLenient().create();
+    strict = new GsonBuilder().create();
+  }
+
+  public void testLenientArray() {
+    assertArrayEquals(new String[] {"example"}, lenient.fromJson(json, StringArrayBox.class).collection);
+  }
+
+  public void testLenientList() {
+    assertListEquals(List.of("example"), lenient.fromJson(json, StringListBox.class).collection);
+  }
+
+  public void testStrictArray() {
+    try {
+      strict.fromJson(json, StringArrayBox.class);
+      fail("Strict Gson should not deserialize array without brackets");
+    } catch (JsonParseException expected) {
+    }
+  }
+
+  public void testStrictList() {
+    try {
+      strict.fromJson(json, StringListBox.class);
+      fail("Strict Gson should not deserialize list without brackets");
+    } catch (JsonParseException expected) {
+    }
+  }
+}
--- a/gson/src/test/java/com/google/gson/jf/OmitQuotesTest.java
+++ b/gson/src/test/java/com/google/gson/jf/OmitQuotesTest.java
@ -0,0 +1,33 @@
+package com.google.gson.jf;
+
+import com.google.gson.*;
+import junit.framework.*;
+
+import java.util.*;
+
+import static com.google.gson.jf.ExtraAssert.*;
+
+public class OmitQuotesTest extends TestCase {
+    private Gson lenient;
+    private Gson strict;
+    private static final String lenientJson = "{collection:[\"example\"]}";
+    private static final String strictJson = "{\"collection\":[\"example\"]}";
+    private StringListBox slb;
+
+    @Override
+    protected void setUp() throws Exception {
+        super.setUp();
+        lenient = new GsonBuilder().setOmitQuotes().create();
+        strict = new GsonBuilder().create();
+        slb = new StringListBox();
+        slb.collection = List.of("example");
+    }
+
+    public void testLenient() {
+        assertEquals(lenientJson, lenient.toJson(slb));
+    }
+
+    public void testStrict() {
+        assertEquals(strictJson, strict.toJson(slb));
+    }
+}
--- a/gson/src/test/java/com/google/gson/regression/JsonAdapterNullSafeTest.java
+++ b/gson/src/test/java/com/google/gson/regression/JsonAdapterNullSafeTest.java
@ -32,7 +32,7 @@ public class JsonAdapterNullSafeTest extends TestCase {
  }

  public void testNullSafeBugDeserialize() throws Exception {
-    Device device = gson.fromJson("{'id':'ec57803e2'}", Device.class);
+    Device device = gson.fromJson("{\"id\":\"ec57803e2\"}", Device.class);
    assertEquals("ec57803e2", device.id);
  }

--- a/gson/src/test/java/com/google/gson/stream/JsonReaderTest.java
+++ b/gson/src/test/java/com/google/gson/stream/JsonReaderTest.java
@ -1172,7 +1172,7 @@ public final class JsonReaderTest extends TestCase {
    try {
      reader.nextNull();
      fail();
-    } catch (IOException expected) {
+    } catch (IllegalStateException expected) {
    }

    reader = new JsonReader(reader("[,]"));
@ -1189,14 +1189,14 @@ public final class JsonReaderTest extends TestCase {
    reader.setLenient(true);
    reader.beginArray();
    assertEquals(true, reader.nextBoolean());
-    reader.nextNull();
+    //reader.nextNull();
    assertEquals(true, reader.nextBoolean());
    reader.endArray();

    reader = new JsonReader(reader("[,true]"));
    reader.setLenient(true);
    reader.beginArray();
-    reader.nextNull();
+    //reader.nextNull();
    assertEquals(true, reader.nextBoolean());
    reader.endArray();

@ -1204,14 +1204,14 @@ public final class JsonReaderTest extends TestCase {
    reader.setLenient(true);
    reader.beginArray();
    assertEquals(true, reader.nextBoolean());
-    reader.nextNull();
+    //reader.nextNull();
    reader.endArray();

    reader = new JsonReader(reader("[,]"));
    reader.setLenient(true);
    reader.beginArray();
-    reader.nextNull();
-    reader.nextNull();
+    //reader.nextNull();
+    //reader.nextNull();
    reader.endArray();
  }

@ -1239,7 +1239,7 @@ public final class JsonReaderTest extends TestCase {
    try {
      reader.skipValue();
      fail();
-    } catch (IOException expected) {
+    } catch (IllegalStateException expected) {
    }

    reader = new JsonReader(reader("[,]"));
@ -1379,46 +1379,46 @@ public final class JsonReaderTest extends TestCase {
  }

  public void testFailWithPosition() throws IOException {
-    testFailWithPosition("Expected value at line 6 column 5 path $[1]",
+    testFailWithPosition("Expected value at line 6 column 5 (char '}') path $[1]",
        "[\n\n\n\n\n\"a\",}]");
  }

  public void testFailWithPositionGreaterThanBufferSize() throws IOException {
    String spaces = repeat(' ', 8192);
-    testFailWithPosition("Expected value at line 6 column 5 path $[1]",
+    testFailWithPosition("Expected value at line 6 column 5 (char '}') path $[1]",
        "[\n\n" + spaces + "\n\n\n\"a\",}]");
  }

  public void testFailWithPositionOverSlashSlashEndOfLineComment() throws IOException {
-    testFailWithPosition("Expected value at line 5 column 6 path $[1]",
+    testFailWithPosition("Expected value at line 5 column 6 (char '}') path $[1]",
        "\n// foo\n\n//bar\r\n[\"a\",}");
  }

  public void testFailWithPositionOverHashEndOfLineComment() throws IOException {
-    testFailWithPosition("Expected value at line 5 column 6 path $[1]",
+    testFailWithPosition("Expected value at line 5 column 6 (char '}') path $[1]",
        "\n# foo\n\n#bar\r\n[\"a\",}");
  }

  public void testFailWithPositionOverCStyleComment() throws IOException {
-    testFailWithPosition("Expected value at line 6 column 12 path $[1]",
+    testFailWithPosition("Expected value at line 6 column 12 (char '}') path $[1]",
        "\n\n/* foo\n*\n*\r\nbar */[\"a\",}");
  }

  public void testFailWithPositionOverQuotedString() throws IOException {
-    testFailWithPosition("Expected value at line 5 column 3 path $[1]",
+    testFailWithPosition("Expected value at line 5 column 3 (char '}') path $[1]",
        "[\"foo\nbar\r\nbaz\n\",\n  }");
  }

  public void testFailWithPositionOverUnquotedString() throws IOException {
-    testFailWithPosition("Expected value at line 5 column 2 path $[1]", "[\n\nabcd\n\n,}");
+    testFailWithPosition("Expected value at line 5 column 2 (char '}') path $[1]", "[\n\nabcd\n\n,}");
  }

  public void testFailWithEscapedNewlineCharacter() throws IOException {
-    testFailWithPosition("Expected value at line 5 column 3 path $[1]", "[\n\n\"\\\n\n\",}");
+    testFailWithPosition("Expected value at line 5 column 3 (char '}') path $[1]", "[\n\n\"\\\n\n\",}");
  }

  public void testFailWithPositionIsOffsetByBom() throws IOException {
-    testFailWithPosition("Expected value at line 1 column 6 path $[1]",
+    testFailWithPosition("Expected value at line 1 column 6 (char '}') path $[1]",
        "\ufeff[\"a\",}]");
  }

@ -1461,7 +1461,7 @@ public final class JsonReaderTest extends TestCase {
      reader.peek();
      fail();
    } catch (IOException expected) {
-      assertEquals("Expected value at line 1 column 14 path $[1].a[2]", expected.getMessage());
+      assertEquals("Expected value at line 1 column 14 (char '}') path $[1].a[2]", expected.getMessage());
    }
  }

@ -1728,7 +1728,7 @@ public final class JsonReaderTest extends TestCase {
    assertDocument("{\"name\"=>\"string\",", BEGIN_OBJECT, NAME, STRING, IOException.class);
    assertDocument("{\"name\"=>\"string\",\"name\"", BEGIN_OBJECT, NAME, STRING, NAME);
    assertDocument("[}", BEGIN_ARRAY, IOException.class);
-    assertDocument("[,]", BEGIN_ARRAY, NULL, NULL, END_ARRAY);
+    assertDocument("[,]", BEGIN_ARRAY, END_ARRAY);
    assertDocument("{", BEGIN_OBJECT, IOException.class);
    assertDocument("{\"name\"", BEGIN_OBJECT, NAME, IOException.class);
    assertDocument("{\"name\",", BEGIN_OBJECT, NAME, IOException.class);