Implement JSON parsing in C#.

This includes all the well-known types except Any.
Some aspects are likely to require further work when the details of the JSON parsing expectations are hammered out in more detail. Some of these have "ignored" tests already.

Note that the choice *not* to use Json.NET was made for two reasons:
- Going from 0 dependencies to 1 dependency is a big hit, and there's not much benefit here
- Json.NET parses more leniently than we'd want; accommodating that would be nearly as much work as writing the tokenizer
This only really affects the JsonTokenizer, which could be replaced by Json.NET. The JsonParser code would be about the same length with Json.NET... but I wouldn't be as confident in it.

1 files changed, 727 insertions, 0 deletions

diff --git a/csharp/src/Google.Protobuf.Test/JsonParserTest.cs b/csharp/src/Google.Protobuf.Test/JsonParserTest.cs
new file mode 100644
index 00000000..b1c7b46c
--- /dev/null
+++ b/csharp/src/Google.Protobuf.Test/JsonParserTest.cs
@@ -0,0 +1,727 @@
+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#endregion
+
+using Google.Protobuf.TestProtos;
+using Google.Protobuf.WellKnownTypes;
+using NUnit.Framework;
+using System;
+
+namespace Google.Protobuf
+{
+    /// <summary>
+    /// Unit tests for JSON parsing. Some tests are ignored at the moment as the desired behaviour
+    /// isn't fully known, either in terms of which exceptions should be thrown or whether they should
+    /// count as valid values.
+    /// </summary>
+    public class JsonParserTest
+    {
+        // Sanity smoke test
+        [Test]
+        public void AllTypesRoundtrip()
+        {
+            AssertRoundtrip(SampleMessages.CreateFullTestAllTypes());
+        }
+
+        [Test]
+        public void Maps()
+        {
+            AssertRoundtrip(new TestMap { MapStringString = { { "with spaces", "bar" }, { "a", "b" } } });
+            AssertRoundtrip(new TestMap { MapInt32Int32 = { { 0, 1 }, { 2, 3 } } });
+            AssertRoundtrip(new TestMap { MapBoolBool = { { false, true }, { true, false } } });
+        }
+
+        [Test]
+        [TestCase(" 1 ")]
+        [TestCase("+1")]
+        [TestCase("1,000")]
+        [TestCase("1.5")]
+        public void IntegerMapKeysAreStrict(string keyText)
+        {
+            // Test that integer parsing is strict. We assume that if this is correct for int32,
+            // it's correct for other numeric key types.
+            var json = "{ \"mapInt32Int32\": { \"" + keyText + "\" : \"1\" } }";
+            Assert.Throws<InvalidProtocolBufferException>(() => JsonParser.Default.Parse<TestMap>(json));
+        }
+
+        [Test]
+        public void SourceContextRoundtrip()
+        {
+            AssertRoundtrip(new SourceContext { FileName = "foo.proto" });
+        }
+
+        [Test]
+        public void SingularWrappers_DefaultNonNullValues()
+        {
+            var message = new TestWellKnownTypes
+            {
+                StringField = "",
+                BytesField = ByteString.Empty,
+                BoolField = false,
+                FloatField = 0f,
+                DoubleField = 0d,
+                Int32Field = 0,
+                Int64Field = 0,
+                Uint32Field = 0,
+                Uint64Field = 0
+            };
+            AssertRoundtrip(message);
+        }
+
+        [Test]
+        public void SingularWrappers_NonDefaultValues()
+        {
+            var message = new TestWellKnownTypes
+            {
+                StringField = "x",
+                BytesField = ByteString.CopyFrom(1, 2, 3),
+                BoolField = true,
+                FloatField = 12.5f,
+                DoubleField = 12.25d,
+                Int32Field = 1,
+                Int64Field = 2,
+                Uint32Field = 3,
+                Uint64Field = 4
+            };
+            AssertRoundtrip(message);
+        }
+
+        [Test]
+        public void SingularWrappers_ExplicitNulls()
+        {
+            var message = new TestWellKnownTypes();
+            var json = new JsonFormatter(new JsonFormatter.Settings(true)).Format(message);
+            var parsed = JsonParser.Default.Parse<TestWellKnownTypes>(json);
+            Assert.AreEqual(message, parsed);
+        }
+
+        [Test]
+        [TestCase(typeof(Int32Value), "32", 32)]
+        [TestCase(typeof(Int64Value), "32", 32L)]
+        [TestCase(typeof(UInt32Value), "32", 32U)]
+        [TestCase(typeof(UInt64Value), "32", 32UL)]
+        [TestCase(typeof(StringValue), "\"foo\"", "foo")]
+        [TestCase(typeof(FloatValue), "1.5", 1.5f)]
+        [TestCase(typeof(DoubleValue), "1.5", 1.5d)]
+        public void Wrappers_Standalone(System.Type wrapperType, string json, object expectedValue)
+        {
+            IMessage parsed = (IMessage) Activator.CreateInstance(wrapperType);
+            IMessage expected = (IMessage) Activator.CreateInstance(wrapperType);
+            JsonParser.Default.Merge(parsed, "null");
+            Assert.AreEqual(expected, parsed);
+
+            JsonParser.Default.Merge(parsed, json);
+            expected.Descriptor.Fields[Wrappers.WrapperValueFieldNumber].Accessor.SetValue(expected, expectedValue);
+            Assert.AreEqual(expected, parsed);
+        }
+
+        [Test]
+        public void BytesWrapper_Standalone()
+        {
+            ByteString data = ByteString.CopyFrom(1, 2, 3);
+            // Can't do this with attributes...
+            var parsed = JsonParser.Default.Parse<BytesValue>("\"" + data.ToBase64() + "\"");
+            var expected = new BytesValue { Value = data };
+            Assert.AreEqual(expected, parsed);
+        }
+
+        [Test]
+        public void RepeatedWrappers()
+        {
+            var message = new RepeatedWellKnownTypes
+            {
+                BoolField = { true, false },
+                BytesField = { ByteString.CopyFrom(1, 2, 3), ByteString.CopyFrom(4, 5, 6), ByteString.Empty },
+                DoubleField = { 12.5, -1.5, 0d },
+                FloatField = { 123.25f, -20f, 0f },
+                Int32Field = { int.MaxValue, int.MinValue, 0 },
+                Int64Field = { long.MaxValue, long.MinValue, 0L },
+                StringField = { "First", "Second", "" },
+                Uint32Field = { uint.MaxValue, uint.MinValue, 0U },
+                Uint64Field = { ulong.MaxValue, ulong.MinValue, 0UL },
+            };
+            AssertRoundtrip(message);
+        }
+
+        [Test]
+        public void IndividualWrapperTypes()
+        {
+            Assert.AreEqual(new StringValue { Value = "foo" }, StringValue.Parser.ParseJson("\"foo\""));
+            Assert.AreEqual(new Int32Value { Value = 1 }, Int32Value.Parser.ParseJson("1"));
+            // Can parse strings directly too
+            Assert.AreEqual(new Int32Value { Value = 1 }, Int32Value.Parser.ParseJson("\"1\""));
+        }
+
+        private static void AssertRoundtrip<T>(T message) where T : IMessage<T>, new()
+        {
+            var clone = message.Clone();
+            var json = message.ToString();
+            var parsed = JsonParser.Default.Parse<T>(json);
+            Assert.AreEqual(clone, parsed);
+        }
+
+        [Test]
+        [TestCase("0", 0)]
+        [TestCase("-0", 0)] // Not entirely clear whether we intend to allow this...
+        [TestCase("1", 1)]
+        [TestCase("-1", -1)]
+        [TestCase("2147483647", 2147483647)]
+        [TestCase("-2147483648", -2147483648)]
+        public void StringToInt32_Valid(string jsonValue, int expectedParsedValue)
+        {
+            string json = "{ \"singleInt32\": \"" + jsonValue + "\"}";
+            var parsed = TestAllTypes.Parser.ParseJson(json);
+            Assert.AreEqual(expectedParsedValue, parsed.SingleInt32);
+        }
+
+        [Test]
+        [TestCase("+0")]
+        [TestCase("00")]
+        [TestCase("-00")]
+        [TestCase("--1")]
+        [TestCase("+1")]
+        [TestCase("1.5")]
+        [TestCase("1e10")]
+        [TestCase("2147483648")]
+        [TestCase("-2147483649")]
+        public void StringToInt32_Invalid(string jsonValue)
+        {
+            string json = "{ \"singleInt32\": \"" + jsonValue + "\"}";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+
+        [Test]
+        [TestCase("0", 0U)]
+        [TestCase("1", 1U)]
+        [TestCase("4294967295", 4294967295U)]
+        public void StringToUInt32_Valid(string jsonValue, uint expectedParsedValue)
+        {
+            string json = "{ \"singleUint32\": \"" + jsonValue + "\"}";
+            var parsed = TestAllTypes.Parser.ParseJson(json);
+            Assert.AreEqual(expectedParsedValue, parsed.SingleUint32);
+        }
+
+        // Assume that anything non-bounds-related is covered in the Int32 case
+        [Test]
+        [TestCase("-1")]
+        [TestCase("4294967296")]
+        public void StringToUInt32_Invalid(string jsonValue)
+        {
+            string json = "{ \"singleUint32\": \"" + jsonValue + "\"}";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+
+        [Test]
+        [TestCase("0", 0L)]
+        [TestCase("1", 1L)]
+        [TestCase("-1", -1L)]
+        [TestCase("9223372036854775807", 9223372036854775807)]
+        [TestCase("-9223372036854775808", -9223372036854775808)]
+        public void StringToInt64_Valid(string jsonValue, long expectedParsedValue)
+        {
+            string json = "{ \"singleInt64\": \"" + jsonValue + "\"}";
+            var parsed = TestAllTypes.Parser.ParseJson(json);
+            Assert.AreEqual(expectedParsedValue, parsed.SingleInt64);
+        }
+
+        // Assume that anything non-bounds-related is covered in the Int32 case
+        [Test]
+        [TestCase("-9223372036854775809")]
+        [TestCase("9223372036854775808")]
+        public void StringToInt64_Invalid(string jsonValue)
+        {
+            string json = "{ \"singleInt64\": \"" + jsonValue + "\"}";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+
+        [Test]
+        [TestCase("0", 0UL)]
+        [TestCase("1", 1UL)]
+        [TestCase("18446744073709551615", 18446744073709551615)]
+        public void StringToUInt64_Valid(string jsonValue, ulong expectedParsedValue)
+        {
+            string json = "{ \"singleUint64\": \"" + jsonValue + "\"}";
+            var parsed = TestAllTypes.Parser.ParseJson(json);
+            Assert.AreEqual(expectedParsedValue, parsed.SingleUint64);
+        }
+
+        // Assume that anything non-bounds-related is covered in the Int32 case
+        [Test]
+        [TestCase("-1")]
+        [TestCase("18446744073709551616")]
+        public void StringToUInt64_Invalid(string jsonValue)
+        {
+            string json = "{ \"singleUint64\": \"" + jsonValue + "\"}";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+
+        [Test]
+        [TestCase("0", 0d)]
+        [TestCase("1", 1d)]
+        [TestCase("1.000000", 1d)]
+        [TestCase("1.0000000000000000000000001", 1d)] // We don't notice that we haven't preserved the exact value
+        [TestCase("-1", -1d)]
+        [TestCase("1e1", 10d)]
+        [TestCase("1e01", 10d)] // Leading decimals are allowed in exponents
+        [TestCase("1E1", 10d)] // Either case is fine
+        [TestCase("-1e1", -10d)]
+        [TestCase("1.5e1", 15d)]
+        [TestCase("-1.5e1", -15d)]
+        [TestCase("15e-1", 1.5d)]
+        [TestCase("-15e-1", -1.5d)]
+        [TestCase("1.79769e308", 1.79769e308)]
+        [TestCase("-1.79769e308", -1.79769e308)]
+        [TestCase("Infinity", double.PositiveInfinity)]
+        [TestCase("-Infinity", double.NegativeInfinity)]
+        [TestCase("NaN", double.NaN)]
+        public void StringToDouble_Valid(string jsonValue, double expectedParsedValue)
+        {
+            string json = "{ \"singleDouble\": \"" + jsonValue + "\"}";
+            var parsed = TestAllTypes.Parser.ParseJson(json);
+            Assert.AreEqual(expectedParsedValue, parsed.SingleDouble);
+        }
+
+        [Test]
+        [TestCase("1.7977e308")]
+        [TestCase("-1.7977e308")]
+        [TestCase("1e309")]
+        [TestCase("1,0")]
+        [TestCase("1.0.0")]
+        [TestCase("+1")]
+        [TestCase("00")]
+        [TestCase("--1")]
+        [TestCase("\u00BD")] // 1/2 as a single Unicode character. Just sanity checking...
+        public void StringToDouble_Invalid(string jsonValue)
+        {
+            string json = "{ \"singleDouble\": \"" + jsonValue + "\"}";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+
+        [Test]
+        [TestCase("0", 0f)]
+        [TestCase("1", 1f)]
+        [TestCase("1.000000", 1f)]
+        [TestCase("-1", -1f)]
+        [TestCase("3.402823e38", 3.402823e38f)]
+        [TestCase("-3.402823e38", -3.402823e38f)]
+        [TestCase("1.5e1", 15f)]
+        [TestCase("15e-1", 1.5f)]
+        public void StringToFloat_Valid(string jsonValue, float expectedParsedValue)
+        {
+            string json = "{ \"singleFloat\": \"" + jsonValue + "\"}";
+            var parsed = TestAllTypes.Parser.ParseJson(json);
+            Assert.AreEqual(expectedParsedValue, parsed.SingleFloat);
+        }
+
+        [Test]
+        [TestCase("3.402824e38")]
+        [TestCase("-3.402824e38")]
+        [TestCase("1,0")]
+        [TestCase("1.0.0")]
+        [TestCase("+1")]
+        [TestCase("00")]
+        [TestCase("--1")]
+        public void StringToFloat_Invalid(string jsonValue)
+        {
+            string json = "{ \"singleFloat\": \"" + jsonValue + "\"}";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+
+        [Test]
+        [TestCase("0", 0)]
+        [TestCase("-0", 0)] // Not entirely clear whether we intend to allow this...
+        [TestCase("1", 1)]
+        [TestCase("-1", -1)]
+        [TestCase("2147483647", 2147483647)]
+        [TestCase("-2147483648", -2147483648)]
+        public void NumberToInt32_Valid(string jsonValue, int expectedParsedValue)
+        {
+            string json = "{ \"singleInt32\": " + jsonValue + "}";
+            var parsed = TestAllTypes.Parser.ParseJson(json);
+            Assert.AreEqual(expectedParsedValue, parsed.SingleInt32);
+        }
+
+        [Test]
+        [TestCase("+0")]
+        [TestCase("00")]
+        [TestCase("-00")]
+        [TestCase("--1")]
+        [TestCase("+1")]
+        [TestCase("1.5", Ignore = true, Reason = "Desired behaviour unclear")]
+        [TestCase("1e10")]
+        [TestCase("2147483648")]
+        [TestCase("-2147483649")]
+        public void NumberToInt32_Invalid(string jsonValue)
+        {
+            string json = "{ \"singleInt32\": " + jsonValue + "}";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+
+        [Test]
+        [TestCase("0", 0U)]
+        [TestCase("1", 1U)]
+        [TestCase("4294967295", 4294967295U)]
+        public void NumberToUInt32_Valid(string jsonValue, uint expectedParsedValue)
+        {
+            string json = "{ \"singleUint32\": " + jsonValue + "}";
+            var parsed = TestAllTypes.Parser.ParseJson(json);
+            Assert.AreEqual(expectedParsedValue, parsed.SingleUint32);
+        }
+
+        // Assume that anything non-bounds-related is covered in the Int32 case
+        [Test]
+        [TestCase("-1")]
+        [TestCase("4294967296")]
+        public void NumberToUInt32_Invalid(string jsonValue)
+        {
+            string json = "{ \"singleUint32\": " + jsonValue + "}";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+
+        [Test]
+        [TestCase("0", 0L)]
+        [TestCase("1", 1L)]
+        [TestCase("-1", -1L)]
+        [TestCase("9223372036854775807", 9223372036854775807, Ignore = true, Reason = "Desired behaviour unclear")]
+        [TestCase("-9223372036854775808", -9223372036854775808, Ignore = true, Reason = "Desired behaviour unclear")]
+        public void NumberToInt64_Valid(string jsonValue, long expectedParsedValue)
+        {
+            string json = "{ \"singleInt64\": " + jsonValue + "}";
+            var parsed = TestAllTypes.Parser.ParseJson(json);
+            Assert.AreEqual(expectedParsedValue, parsed.SingleInt64);
+        }
+
+        // Assume that anything non-bounds-related is covered in the Int32 case
+        [Test]
+        [TestCase("-9223372036854775809", Ignore = true, Reason = "Desired behaviour unclear")]
+        [TestCase("9223372036854775808", Ignore = true, Reason = "Desired behaviour unclear")]
+        public void NumberToInt64_Invalid(string jsonValue)
+        {
+            string json = "{ \"singleInt64\": " + jsonValue + "}";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+
+        [Test]
+        [TestCase("0", 0UL)]
+        [TestCase("1", 1UL)]
+        [TestCase("18446744073709551615", 18446744073709551615, Ignore = true, Reason = "Desired behaviour unclear")]
+        public void NumberToUInt64_Valid(string jsonValue, ulong expectedParsedValue)
+        {
+            string json = "{ \"singleUint64\": " + jsonValue + "}";
+            var parsed = TestAllTypes.Parser.ParseJson(json);
+            Assert.AreEqual(expectedParsedValue, parsed.SingleUint64);
+        }
+
+        // Assume that anything non-bounds-related is covered in the Int32 case
+        [Test]
+        [TestCase("-1")]
+        [TestCase("18446744073709551616")]
+        public void NumberToUInt64_Invalid(string jsonValue)
+        {
+            string json = "{ \"singleUint64\": " + jsonValue + "}";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+
+        [Test]
+        [TestCase("0", 0d)]
+        [TestCase("1", 1d)]
+        [TestCase("1.000000", 1d)]
+        [TestCase("1.0000000000000000000000001", 1d)] // We don't notice that we haven't preserved the exact value
+        [TestCase("-1", -1d)]
+        [TestCase("1e1", 10d)]
+        [TestCase("1e01", 10d)] // Leading decimals are allowed in exponents
+        [TestCase("1E1", 10d)] // Either case is fine
+        [TestCase("-1e1", -10d)]
+        [TestCase("1.5e1", 15d)]
+        [TestCase("-1.5e1", -15d)]
+        [TestCase("15e-1", 1.5d)]
+        [TestCase("-15e-1", -1.5d)]
+        [TestCase("1.79769e308", 1.79769e308)]
+        [TestCase("-1.79769e308", -1.79769e308)]
+        public void NumberToDouble_Valid(string jsonValue, double expectedParsedValue)
+        {
+            string json = "{ \"singleDouble\": " + jsonValue + "}";
+            var parsed = TestAllTypes.Parser.ParseJson(json);
+            Assert.AreEqual(expectedParsedValue, parsed.SingleDouble);
+        }
+
+        [Test]
+        [TestCase("1.7977e308", Ignore = true, Reason = "Desired behaviour unclear")]
+        [TestCase("-1.7977e308", Ignore = true, Reason = "Desired behaviour unclear")]
+        [TestCase("1e309", Ignore = true, Reason = "Desired behaviour unclear")]
+        [TestCase("1,0")]
+        [TestCase("1.0.0")]
+        [TestCase("+1")]
+        [TestCase("00")]
+        [TestCase("--1")]
+        [TestCase("\u00BD")] // 1/2 as a single Unicode character. Just sanity checking...
+        public void NumberToDouble_Invalid(string jsonValue)
+        {
+            string json = "{ \"singleDouble\": " + jsonValue + "}";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+
+        [Test]
+        [TestCase("0", 0f)]
+        [TestCase("1", 1f)]
+        [TestCase("1.000000", 1f)]
+        [TestCase("-1", -1f)]
+        [TestCase("3.402823e38", 3.402823e38f)]
+        [TestCase("-3.402823e38", -3.402823e38f)]
+        [TestCase("1.5e1", 15f)]
+        [TestCase("15e-1", 1.5f)]
+        public void NumberToFloat_Valid(string jsonValue, float expectedParsedValue)
+        {
+            string json = "{ \"singleFloat\": " + jsonValue + "}";
+            var parsed = TestAllTypes.Parser.ParseJson(json);
+            Assert.AreEqual(expectedParsedValue, parsed.SingleFloat);
+        }
+
+        [Test]
+        [TestCase("3.402824e38")]
+        [TestCase("-3.402824e38")]
+        [TestCase("1,0")]
+        [TestCase("1.0.0")]
+        [TestCase("+1")]
+        [TestCase("00")]
+        [TestCase("--1")]
+        public void NumberToFloat_Invalid(string jsonValue)
+        {
+            string json = "{ \"singleFloat\": " + jsonValue + "}";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+
+        // The simplest way of testing that the value has parsed correctly is to reformat it,
+        // as we trust the formatting. In many cases that will give the same result as the input,
+        // so in those cases we accept an expectedFormatted value of null. Sometimes the results
+        // will be different though, due to a different number of digits being provided.
+        [Test]
+        // Z offset
+        [TestCase("2015-10-09T14:46:23.123456789Z", null)]
+        [TestCase("2015-10-09T14:46:23.123456Z", null)]
+        [TestCase("2015-10-09T14:46:23.123Z", null)]
+        [TestCase("2015-10-09T14:46:23Z", null)]
+        [TestCase("2015-10-09T14:46:23.123456000Z", "2015-10-09T14:46:23.123456Z")]
+        [TestCase("2015-10-09T14:46:23.1234560Z", "2015-10-09T14:46:23.123456Z")]
+        [TestCase("2015-10-09T14:46:23.123000000Z", "2015-10-09T14:46:23.123Z")]
+        [TestCase("2015-10-09T14:46:23.1230Z", "2015-10-09T14:46:23.123Z")]
+        [TestCase("2015-10-09T14:46:23.00Z", "2015-10-09T14:46:23Z")]
+
+        // +00:00 offset
+        [TestCase("2015-10-09T14:46:23.123456789+00:00", "2015-10-09T14:46:23.123456789Z")]
+        [TestCase("2015-10-09T14:46:23.123456+00:00", "2015-10-09T14:46:23.123456Z")]
+        [TestCase("2015-10-09T14:46:23.123+00:00", "2015-10-09T14:46:23.123Z")]
+        [TestCase("2015-10-09T14:46:23+00:00", "2015-10-09T14:46:23Z")]
+        [TestCase("2015-10-09T14:46:23.123456000+00:00", "2015-10-09T14:46:23.123456Z")]
+        [TestCase("2015-10-09T14:46:23.1234560+00:00", "2015-10-09T14:46:23.123456Z")]
+        [TestCase("2015-10-09T14:46:23.123000000+00:00", "2015-10-09T14:46:23.123Z")]
+        [TestCase("2015-10-09T14:46:23.1230+00:00", "2015-10-09T14:46:23.123Z")]
+        [TestCase("2015-10-09T14:46:23.00+00:00", "2015-10-09T14:46:23Z")]
+
+        // Other offsets (assume by now that the subsecond handling is okay)
+        [TestCase("2015-10-09T15:46:23.123456789+01:00", "2015-10-09T14:46:23.123456789Z")]
+        [TestCase("2015-10-09T13:46:23.123456789-01:00", "2015-10-09T14:46:23.123456789Z")]
+        [TestCase("2015-10-09T15:16:23.123456789+00:30", "2015-10-09T14:46:23.123456789Z")]
+        [TestCase("2015-10-09T14:16:23.123456789-00:30", "2015-10-09T14:46:23.123456789Z")]
+        [TestCase("2015-10-09T16:31:23.123456789+01:45", "2015-10-09T14:46:23.123456789Z")]
+        [TestCase("2015-10-09T13:01:23.123456789-01:45", "2015-10-09T14:46:23.123456789Z")]
+        [TestCase("2015-10-10T08:46:23.123456789+18:00", "2015-10-09T14:46:23.123456789Z")]
+        [TestCase("2015-10-08T20:46:23.123456789-18:00", "2015-10-09T14:46:23.123456789Z")]
+
+        // Leap years and min/max
+        [TestCase("2016-02-29T14:46:23.123456789Z", null)]
+        [TestCase("2000-02-29T14:46:23.123456789Z", null)]
+        [TestCase("0001-01-01T00:00:00Z", null)]
+        [TestCase("9999-12-31T23:59:59.999999999Z", null)]
+        public void Timestamp_Valid(string jsonValue, string expectedFormatted)
+        {
+            expectedFormatted = expectedFormatted ?? jsonValue;
+            string json = "\"" + jsonValue + "\"";
+            var parsed = Timestamp.Parser.ParseJson(json);
+            Assert.AreEqual(expectedFormatted, parsed.ToString());
+        }
+        
+        [Test]
+        [TestCase("2015-10-09 14:46:23.123456789Z", Description = "No T between date and time")]
+        [TestCase("2015/10/09T14:46:23.123456789Z", Description = "Wrong date separators")]
+        [TestCase("2015-10-09T14.46.23.123456789Z", Description = "Wrong time separators")]
+        [TestCase("2015-10-09T14:46:23,123456789Z", Description = "Wrong fractional second separators (valid ISO-8601 though)")]
+        [TestCase(" 2015-10-09T14:46:23.123456789Z", Description = "Whitespace at start")]
+        [TestCase("2015-10-09T14:46:23.123456789Z ", Description = "Whitespace at end")]
+        [TestCase("2015-10-09T14:46:23.1234567890", Description = "Too many digits")]
+        [TestCase("2015-10-09T14:46:23.123456789", Description = "No offset")]
+        [TestCase("2015-13-09T14:46:23.123456789Z", Description = "Invalid month")]
+        [TestCase("2015-10-32T14:46:23.123456789Z", Description = "Invalid day")]
+        [TestCase("2015-10-09T24:00:00.000000000Z", Description = "Invalid hour (valid ISO-8601 though)")]
+        [TestCase("2015-10-09T14:60:23.123456789Z", Description = "Invalid minutes")]
+        [TestCase("2015-10-09T14:46:60.123456789Z", Description = "Invalid seconds")]
+        [TestCase("2015-10-09T14:46:23.123456789+18:01", Description = "Offset too large (positive)")]
+        [TestCase("2015-10-09T14:46:23.123456789-18:01", Description = "Offset too large (negative)")]
+        [TestCase("2015-10-09T14:46:23.123456789-00:00", Description = "Local offset (-00:00) makes no sense here")]
+        [TestCase("0001-01-01T00:00:00+00:01", Description = "Value before earliest when offset applied")]
+        [TestCase("9999-12-31T23:59:59.999999999-00:01", Description = "Value after latest when offset applied")]
+        [TestCase("2100-02-29T14:46:23.123456789Z", Description = "Feb 29th on a non-leap-year")]
+        public void Timestamp_Invalid(string jsonValue)
+        {
+            string json = "\"" + jsonValue + "\"";
+            Assert.Throws<InvalidProtocolBufferException>(() => Timestamp.Parser.ParseJson(json));
+        }
+
+        [Test]
+        public void StructValue_Null()
+        {
+            Assert.AreEqual(new Value { NullValue = 0 }, Value.Parser.ParseJson("null"));
+        }
+
+        [Test]
+        public void StructValue_String()
+        {
+            Assert.AreEqual(new Value { StringValue = "hi" }, Value.Parser.ParseJson("\"hi\""));
+        }
+
+        [Test]
+        public void StructValue_Bool()
+        {
+            Assert.AreEqual(new Value { BoolValue = true }, Value.Parser.ParseJson("true"));
+            Assert.AreEqual(new Value { BoolValue = false }, Value.Parser.ParseJson("false"));
+        }
+
+        [Test]
+        public void StructValue_List()
+        {
+            Assert.AreEqual(Value.ForList(Value.ForNumber(1), Value.ForString("x")), Value.Parser.ParseJson("[1, \"x\"]"));
+        }
+
+        [Test]
+        public void ParseListValue()
+        {
+            Assert.AreEqual(new ListValue { Values = { Value.ForNumber(1), Value.ForString("x") } }, ListValue.Parser.ParseJson("[1, \"x\"]"));
+        }
+
+        [Test]
+        public void StructValue_Struct()
+        {
+            Assert.AreEqual(
+                Value.ForStruct(new Struct { Fields = { { "x", Value.ForNumber(1) }, { "y", Value.ForString("z") } } }),
+                Value.Parser.ParseJson("{ \"x\": 1, \"y\": \"z\" }"));
+        }
+
+        [Test]
+        public void ParseStruct()
+        {
+            Assert.AreEqual(new Struct { Fields = { { "x", Value.ForNumber(1) }, { "y", Value.ForString("z") } } },
+                Struct.Parser.ParseJson("{ \"x\": 1, \"y\": \"z\" }"));
+        }
+
+        // TODO for duration parsing: upper and lower bounds.
+        // +/- 315576000000 seconds
+
+        [Test]
+        [TestCase("1.123456789s", null)]
+        [TestCase("1.123456s", null)]
+        [TestCase("1.123s", null)]
+        [TestCase("1.12300s", "1.123s")]
+        [TestCase("1.12345s", "1.123450s")]
+        [TestCase("1s", null)]
+        [TestCase("-1.123456789s", null)]
+        [TestCase("-1.123456s", null)]
+        [TestCase("-1.123s", null)]
+        [TestCase("-1s", null)]
+        [TestCase("0.123s", null)]
+        [TestCase("-0.123s", null)]
+        [TestCase("123456.123s", null)]
+        [TestCase("-123456.123s", null)]
+        // Upper and lower bounds
+        [TestCase("315576000000s", null)]
+        [TestCase("-315576000000s", null)]
+        public void Duration_Valid(string jsonValue, string expectedFormatted)
+        {
+            expectedFormatted = expectedFormatted ?? jsonValue;
+            string json = "\"" + jsonValue + "\"";
+            var parsed = Duration.Parser.ParseJson(json);
+            Assert.AreEqual(expectedFormatted, parsed.ToString());
+        }
+
+        // The simplest way of testing that the value has parsed correctly is to reformat it,
+        // as we trust the formatting. In many cases that will give the same result as the input,
+        // so in those cases we accept an expectedFormatted value of null. Sometimes the results
+        // will be different though, due to a different number of digits being provided.
+        [Test]
+        [TestCase("1.1234567890s", Description = "Too many digits")]
+        [TestCase("1.123456789", Description = "No suffix")]
+        [TestCase("1.123456789ss", Description = "Too much suffix")]
+        [TestCase("1.123456789S", Description = "Upper case suffix")]
+        [TestCase("+1.123456789s", Description = "Leading +")]
+        [TestCase(".123456789s", Description = "No integer before the fraction")]
+        [TestCase("1,123456789s", Description = "Comma as decimal separator")]
+        [TestCase("1x1.123456789s", Description = "Non-digit in integer part")]
+        [TestCase("1.1x3456789s", Description = "Non-digit in fractional part")]
+        [TestCase(" 1.123456789s", Description = "Whitespace before fraction")]
+        [TestCase("1.123456789s ", Description = "Whitespace after value")]
+        [TestCase("01.123456789s", Description = "Leading zero (positive)")]
+        [TestCase("-01.123456789s", Description = "Leading zero (negative)")]
+        [TestCase("--0.123456789s", Description = "Double minus sign")]
+        // Violate upper/lower bounds in various ways
+        [TestCase("315576000001s", Description = "Integer part too large")]
+        [TestCase("315576000000.000000001s", Description = "Integer part is upper bound; non-zero fraction")]
+        [TestCase("3155760000000s", Description = "Integer part too long (positive)")]
+        [TestCase("-3155760000000s", Description = "Integer part too long (negative)")]
+        public void Duration_Invalid(string jsonValue)
+        {
+            string json = "\"" + jsonValue + "\"";
+            Assert.Throws<InvalidProtocolBufferException>(() => Duration.Parser.ParseJson(json));
+        }
+
+        // Not as many tests for field masks as I'd like; more to be added when we have more
+        // detailed specifications.
+
+        [Test]
+        [TestCase("")]
+        [TestCase("foo", "foo")]
+        [TestCase("foo,bar", "foo", "bar")]
+        [TestCase("foo.bar", "foo.bar")]
+        [TestCase("fooBar", "foo_bar")]
+        [TestCase("fooBar.bazQux", "foo_bar.baz_qux")]
+        public void FieldMask_Valid(string jsonValue, params string[] expectedPaths)
+        {
+            string json = "\"" + jsonValue + "\"";
+            var parsed = FieldMask.Parser.ParseJson(json);
+            CollectionAssert.AreEqual(expectedPaths, parsed.Paths);
+        }
+
+        [Test]
+        public void DataAfterObject()
+        {
+            string json = "{} 10";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+    }
+}