What's new in GSON 2.0

GSON 1.x used to automatically unwrap single-element arrays as necessary.
GSON 2.x doesn't.
com.google.gson.functional.ArrayTest.testSingleStringArrayDeserialization
com.google.gson.functional.PrimitiveTest#testPrimitiveIntegerAutoboxedInASingleElementArrayDeserialization
com.google.gson.functional.PrimitiveTest#testPrimitiveLongAutoboxedInASingleElementArrayDeserialization
com.google.gson.functional.PrimitiveTest#testPrimitiveBooleanAutoboxedDeserialization
com.google.gson.functional.PrimitiveTest.testPrimitiveBooleanAutoboxedInASingleElementArrayDeserialization
com.google.gson.functional.PrimitiveTest.testPrimitiveDoubleAutoboxedInASingleElementArrayDeserialization
com.google.gson.functional.PrimitiveTest.testBigDecimalInASingleElementArrayDeserialization
com.google.gson.functional.PrimitiveTest.testBigIntegerInASingleElementArrayDeserialization
com.google.gson.functional.StringTest.testStringValueAsSingleElementArrayDeserialization
com.google.gson.functional.EnumTest.testTopLevelEnumInASingleElementArrayDeserialization

GSON 1.x permitted primitive types to be overridden
GSON 2.x doesn't.
com.google.gson.functional.ArrayTest.testArrayOfPrimitivesWithCustomTypeAdapter
com.google.gson.functional.PrimitiveTest.testOverridingDefaultPrimitiveSerialization


GSON 1.x rejects integers that have any fraction, even if it is ".0"
GSON 2.x permits integers to have ".0" fractions like "1.0"
com.google.gson.functional.PrimitiveTest.testDeserializingDecimalPointValuesAsIntegerFails

GSON 1.x truncates oversized large integers and longs
GSON 2.x fails on oversized large integers and longs
com.google.gson.functional.PrimitiveTest.testDeserializingBigIntegerAsInteger
com.google.gson.functional.PrimitiveTest.testDeserializingBigIntegerAsLong


GSON 1.x uses arbitrary precision for primitive type conversion (so -122.08e-2132 != 0)
GSON 2.x uses double precision (so -122.08e-2132 == 0)
com.google.gson.functional.PrimitiveTest.testDeserializingBigDecimalAsLongFails


GSON 1.x supports type adapters for primitive types
GSON 2.x doesn't
com.google.gson.functional.CustomTypeAdaptersTest.testCustomSerializerForLong
com.google.gson.functional.CustomTypeAdaptersTest.testCustomDeserializerForLong