Set all but main project to nullable

csharp/src/AddressBook/AddPerson.cs

@@ -45,13 +45,13 @@ private static Person PromptForAddress(TextReader input, TextWriter output)
             Person person = new Person();
 
             output.Write("Enter person ID: ");
-            person.Id = int.Parse(input.ReadLine());
+            person.Id = int.Parse(input.ReadLine() ?? string.Empty);
 
             output.Write("Enter name: ");
             person.Name = input.ReadLine();
 
             output.Write("Enter email address (blank for none): ");
-            string email = input.ReadLine();
+            string email = input.ReadLine() ?? string.Empty;
             if (email.Length > 0)
             {
                 person.Email = email;
@@ -60,7 +60,7 @@ private static Person PromptForAddress(TextReader input, TextWriter output)
             while (true)
             {
                 output.Write("Enter a phone number (or leave blank to finish): ");
-                string number = input.ReadLine();
+                string number = input.ReadLine() ?? string.Empty;
                 if (number.Length == 0)
                 {
                     break;
@@ -69,7 +69,7 @@ private static Person PromptForAddress(TextReader input, TextWriter output)
                 Person.Types.PhoneNumber phoneNumber = new Person.Types.PhoneNumber { Number = number };
 
                 output.Write("Is this a mobile, home, or work phone? ");
-                String type = input.ReadLine();
+                String type = input.ReadLine() ?? string.Empty;
                 switch (type)
                 {
                     case "mobile":

csharp/src/AddressBook/AddressBook.csproj

@@ -4,6 +4,7 @@
     <TargetFramework>netcoreapp3.1</TargetFramework>
     <OutputType>Exe</OutputType>
     <StartupObject>Google.Protobuf.Examples.AddressBook.Program</StartupObject>
+    <Nullable>Enable</Nullable>
     <IsPackable>False</IsPackable>
   </PropertyGroup>
 

csharp/src/Google.Protobuf.JsonDump/Google.Protobuf.JsonDump.csproj

@@ -3,6 +3,7 @@
   <PropertyGroup>
     <TargetFramework>netcoreapp3.1</TargetFramework>
     <OutputType>Exe</OutputType>
+    <Nullable>Enable</Nullable>
     <IsPackable>False</IsPackable>
   </PropertyGroup>
 

csharp/src/Google.Protobuf.JsonDump/Program.cs

@@ -50,7 +50,7 @@ private static int Main(string[] args)
                 Console.Error.WriteLine("including assembly e.g. ProjectNamespace.Message,Company.Project");
                 return 1;
             }
-            Type type = Type.GetType(args[0]);
+            Type? type = Type.GetType(args[0]);
             if (type == null)
             {
                 Console.Error.WriteLine("Unable to load type {0}.", args[0]);
@@ -61,7 +61,7 @@ private static int Main(string[] args)
                 Console.Error.WriteLine("Type {0} doesn't implement IMessage.", args[0]);
                 return 1;
             }
-            IMessage message = (IMessage) Activator.CreateInstance(type);
+            IMessage message = (IMessage) Activator.CreateInstance(type)!;
             using (var input = File.OpenRead(args[1]))
             {
                 message.MergeFrom(input);

csharp/src/Google.Protobuf.Test.TestProtos/Google.Protobuf.Test.TestProtos.csproj

@@ -9,6 +9,7 @@
     <TargetFrameworks>net462;netstandard1.1;netstandard2.0</TargetFrameworks>
     <LangVersion>10.0</LangVersion>
     <AssemblyOriginatorKeyFile>../../keys/Google.Protobuf.snk</AssemblyOriginatorKeyFile>
+    <Nullable>Enable</Nullable>
     <SignAssembly>true</SignAssembly>
     <IsPackable>False</IsPackable>
   </PropertyGroup>

csharp/src/Google.Protobuf.Test/ByteStringTest.cs

@@ -39,8 +39,6 @@
 using System.Linq;
 using System.Buffers;
 using System.Runtime.InteropServices;
-using System.Threading;
-using System.Runtime.CompilerServices;
 using System.Threading.Tasks;
 
 namespace Google.Protobuf
@@ -66,15 +64,15 @@ public void Equality()
             Assert.IsFalse(b1 == b3);
             Assert.IsFalse(b1 == b4);
             Assert.IsFalse(b1 == null);
-            Assert.IsTrue((ByteString) null == null);
+            Assert.IsTrue((ByteString?) null == null);
             Assert.IsFalse(b1 != b1);
             Assert.IsFalse(b1 != b2);
             Assert.IsTrue(ByteString.Empty == ByteString.Empty);
 #pragma warning restore 1718
             Assert.IsTrue(b1 != b3);
             Assert.IsTrue(b1 != b4);
             Assert.IsTrue(b1 != null);
-            Assert.IsFalse((ByteString) null != null);
+            Assert.IsFalse((ByteString?) null != null);
         }
 
         [Test]

csharp/src/Google.Protobuf.Test/CodedInputStreamTest.cs

@@ -119,11 +119,11 @@ private static void AssertReadVarint(byte[] data, ulong value)
         private static void AssertReadVarintFailure(InvalidProtocolBufferException expected, byte[] data)
         {
             CodedInputStream input = new CodedInputStream(data);
-            var exception = Assert.Throws<InvalidProtocolBufferException>(() => input.ReadRawVarint32());
+            var exception = Assert.Throws<InvalidProtocolBufferException>(() => input.ReadRawVarint32())!;
             Assert.AreEqual(expected.Message, exception.Message);
 
             input = new CodedInputStream(data);
-            exception = Assert.Throws<InvalidProtocolBufferException>(() => input.ReadRawVarint64());
+            exception = Assert.Throws<InvalidProtocolBufferException>(() => input.ReadRawVarint64())!;
             Assert.AreEqual(expected.Message, exception.Message);
 
             AssertReadFromParseContext(new ReadOnlySequence<byte>(data), (ref ParseContext ctx) =>
@@ -153,7 +153,7 @@ private static void AssertReadVarintFailure(InvalidProtocolBufferException expec
             }, false);
 
             // Make sure we get the same error when reading directly from a Stream.
-            exception = Assert.Throws<InvalidProtocolBufferException>(() => CodedInputStream.ReadRawVarint32(new MemoryStream(data)));
+            exception = Assert.Throws<InvalidProtocolBufferException>(() => CodedInputStream.ReadRawVarint32(new MemoryStream(data)))!;
             Assert.AreEqual(expected.Message, exception.Message);
         }
 
@@ -876,9 +876,9 @@ public void RecursionLimitAppliedWhileSkippingGroup()
         [Test]
         public void Construction_Invalid()
         {
-            Assert.Throws<ArgumentNullException>(() => new CodedInputStream((byte[]) null));
+            Assert.Throws<ArgumentNullException>(() => new CodedInputStream((byte[]?) null));
             Assert.Throws<ArgumentNullException>(() => new CodedInputStream(null, 0, 0));
-            Assert.Throws<ArgumentNullException>(() => new CodedInputStream((Stream) null));
+            Assert.Throws<ArgumentNullException>(() => new CodedInputStream((Stream?) null));
             Assert.Throws<ArgumentOutOfRangeException>(() => new CodedInputStream(new byte[10], 100, 0));
             Assert.Throws<ArgumentOutOfRangeException>(() => new CodedInputStream(new byte[10], 5, 10));
         }

csharp/src/Google.Protobuf.Test/Collections/MapFieldTest.cs

@@ -67,9 +67,9 @@ public void NullValuesProhibited()
         private void TestNullValues<T>(T nonNullValue)
         {
             var map = new MapField<int, T>();
-            var nullValue = (T) (object) null;
-            Assert.Throws<ArgumentNullException>(() => map.Add(0, nullValue));
-            Assert.Throws<ArgumentNullException>(() => map[0] = nullValue);
+            var nullValue = (T?) (object?) null;
+            Assert.Throws<ArgumentNullException>(() => map.Add(0, nullValue!));
+            Assert.Throws<ArgumentNullException>(() => map[0] = nullValue!);
             map.Add(1, nonNullValue);
             map[1] = nonNullValue;
         }
@@ -78,14 +78,14 @@ private void TestNullValues<T>(T nonNullValue)
         public void Add_ForbidsNullKeys()
         {
             var map = new MapField<string, ForeignMessage>();
-            Assert.Throws<ArgumentNullException>(() => map.Add(null, new ForeignMessage()));
+            Assert.Throws<ArgumentNullException>(() => map.Add(null!, new ForeignMessage()));
         }
 
         [Test]
         public void Indexer_ForbidsNullKeys()
         {
             var map = new MapField<string, ForeignMessage>();
-            Assert.Throws<ArgumentNullException>(() => map[null] = new ForeignMessage());
+            Assert.Throws<ArgumentNullException>(() => map[null!] = new ForeignMessage());
         }
 
         [Test]
@@ -230,7 +230,7 @@ public void Remove_Key()
             Assert.AreEqual(1, map.Count);
             Assert.IsTrue(map.Remove("foo"));
             Assert.AreEqual(0, map.Count);
-            Assert.Throws<ArgumentNullException>(() => map.Remove(null));
+            Assert.Throws<ArgumentNullException>(() => map.Remove(null!));
         }
 
         [Test]
@@ -245,7 +245,7 @@ public void Remove_Pair()
             Assert.AreEqual(1, map.Count);
             Assert.IsTrue(collection.Remove(NewKeyValuePair("foo", "bar")));
             Assert.AreEqual(0, map.Count);
-            Assert.Throws<ArgumentException>(() => collection.Remove(new KeyValuePair<string, string>(null, "")));
+            Assert.Throws<ArgumentException>(() => collection.Remove(new KeyValuePair<string, string>(null!, "")));
         }
 
         [Test]
@@ -356,7 +356,7 @@ public void IDictionary_Remove()
             Assert.AreEqual(1, dictionary.Count);
             dictionary.Remove("x");
             Assert.AreEqual(0, dictionary.Count);
-            Assert.Throws<ArgumentNullException>(() => dictionary.Remove(null));
+            Assert.Throws<ArgumentNullException>(() => dictionary.Remove(null!));
         }
 
         [Test]
@@ -369,7 +369,7 @@ public void IDictionary_CopyTo()
             CollectionAssert.AreEqual(new[] { default, new DictionaryEntry("x", "y"), default }, array);
             var objectArray = new object[3];
             dictionary.CopyTo(objectArray, 1);
-            CollectionAssert.AreEqual(new object[] { null, new DictionaryEntry("x", "y"), null }, objectArray);
+            CollectionAssert.AreEqual(new object[] { null!, new DictionaryEntry("x", "y"), null! }, objectArray);
         }
 
         [Test]
@@ -415,7 +415,7 @@ public void IDictionary_Indexer_Get()
             Assert.AreEqual("y", dictionary["x"]);
             Assert.IsNull(dictionary["a"]);
             Assert.IsNull(dictionary[5]);
-            Assert.Throws<ArgumentNullException>(() => dictionary[null].GetHashCode());
+            Assert.Throws<ArgumentNullException>(() => dictionary[null!]!.GetHashCode());
         }
 
         [Test]
@@ -429,7 +429,7 @@ public void IDictionary_Indexer_Set()
             Assert.AreEqual("c", map["a"]);
             Assert.Throws<InvalidCastException>(() => dictionary[5] = "x");
             Assert.Throws<InvalidCastException>(() => dictionary["x"] = 5);
-            Assert.Throws<ArgumentNullException>(() => dictionary[null] = "z");
+            Assert.Throws<ArgumentNullException>(() => dictionary[null!] = "z");
             Assert.Throws<ArgumentNullException>(() => dictionary["x"] = null);
         }
 
@@ -503,7 +503,7 @@ public void KeysContains()
             Assert.IsFalse(keys.Contains("bar")); // It's a value!
             Assert.IsFalse(keys.Contains("1"));
             // Keys can't be null, so we should prevent contains check
-            Assert.Throws<ArgumentNullException>(() => keys.Contains(null));
+            Assert.Throws<ArgumentNullException>(() => keys.Contains(null!));
         }
 
         [Test]
@@ -523,7 +523,7 @@ public void ValuesContains()
             Assert.IsFalse(values.Contains("foo")); // It's a key!
             Assert.IsFalse(values.Contains("1"));
             // Values can be null, so this makes sense
-            Assert.IsFalse(values.Contains(null));
+            Assert.IsFalse(values.Contains(null!));
         }
 
         [Test]

csharp/src/Google.Protobuf.Test/Collections/ProtobufEqualityComparersTest.cs

@@ -99,7 +99,7 @@ public void NullableSingleComparisons()
 
         private static void ValidateEqualityComparer<T>(EqualityComparer<T> comparer, IEnumerable<T> values)
         {
-            var array = values.ToArray();
+            T[] array = values.ToArray();
             // Each value should be equal to itself, but not to any other value.
             for (int i = 0; i < array.Length; i++)
             {
@@ -114,7 +114,7 @@ private static void ValidateEqualityComparer<T>(EqualityComparer<T> comparer, IE
                     {
                         Assert.IsFalse(comparer.Equals(array[i], array[j]),
                             "{0} and {1} should not be equal", array[i], array[j]);
-                        Assert.AreNotEqual(comparer.GetHashCode(array[i]), comparer.GetHashCode(array[j]),
+                        Assert.AreNotEqual(comparer.GetHashCode(array[i]!), comparer.GetHashCode(array[j]!),
                             "Hash codes for {0} and {1} should not be equal", array[i], array[j]);
                     }
                 }

csharp/src/Google.Protobuf.Test/Collections/RepeatedFieldTest.cs

@@ -48,11 +48,11 @@ public class RepeatedFieldTest
         public void NullValuesRejected()
         {
             var list = new RepeatedField<string>();
-            Assert.Throws<ArgumentNullException>(() => list.Add((string)null));
-            Assert.Throws<ArgumentNullException>(() => list.Add((IEnumerable<string>)null));
-            Assert.Throws<ArgumentNullException>(() => list.Add((RepeatedField<string>)null));
-            Assert.Throws<ArgumentNullException>(() => list.Contains(null));
-            Assert.Throws<ArgumentNullException>(() => list.IndexOf(null));
+            Assert.Throws<ArgumentNullException>(() => list.Add((string?)null!));
+            Assert.Throws<ArgumentNullException>(() => list.Add((IEnumerable<string>?)null));
+            Assert.Throws<ArgumentNullException>(() => list.Add((RepeatedField<string>?)null));
+            Assert.Throws<ArgumentNullException>(() => list.Contains(null!));
+            Assert.Throws<ArgumentNullException>(() => list.IndexOf(null!));
         }
 
         [Test]
@@ -88,7 +88,7 @@ public void AddRange_SlowPath_NullsProhibited_ReferenceType()
             var list = new RepeatedField<string>();
             // It's okay for this to throw ArgumentNullException if necessary.
             // It's not ideal, but not awful.
-            Assert.Catch<ArgumentException>(() => list.AddRange(new[] { "foo", null }.Select(x => x)));
+            Assert.Catch<ArgumentException>(() => list.AddRange(new[] { "foo", null! }.Select(x => x)));
         }
 
         [Test]
@@ -137,7 +137,7 @@ public void AddRange_Optimized_NullsProhibited_ReferenceType()
             var list = new RepeatedField<string>();
             // It's okay for this to throw ArgumentNullException if necessary.
             // It's not ideal, but not awful.
-            Assert.Catch<ArgumentException>(() => list.AddRange(new List<string> { "foo", null }));
+            Assert.Catch<ArgumentException>(() => list.AddRange(new List<string> { "foo", null! }));
         }
 
         [Test]
@@ -207,15 +207,15 @@ public void Insert_Invalid()
             var list = new RepeatedField<string> { "first", "second" };
             Assert.Throws<ArgumentOutOfRangeException>(() => list.Insert(-1, "foo"));
             Assert.Throws<ArgumentOutOfRangeException>(() => list.Insert(3, "foo"));
-            Assert.Throws<ArgumentNullException>(() => list.Insert(0, null));
+            Assert.Throws<ArgumentNullException>(() => list.Insert(0, null!));
         }
 
         [Test]
         public void Equals_RepeatedField()
         {
             var list = new RepeatedField<string> { "first", "second" };
-            Assert.IsFalse(list.Equals((RepeatedField<string>) null));
-            Assert.IsTrue(list.Equals(list));
+            Assert.IsFalse(list.Equals((RepeatedField<string>?) null));
+            Assert.IsTrue(list!.Equals(list));
             Assert.IsFalse(list.Equals(new RepeatedField<string> { "first", "third" }));
             Assert.IsFalse(list.Equals(new RepeatedField<string> { "first" }));
             Assert.IsTrue(list.Equals(new RepeatedField<string> { "first", "second" }));
@@ -225,8 +225,8 @@ public void Equals_RepeatedField()
         public void Equals_Object()
         {
             var list = new RepeatedField<string> { "first", "second" };
-            Assert.IsFalse(list.Equals((object) null));
-            Assert.IsTrue(list.Equals((object) list));
+            Assert.IsFalse(list.Equals((object?) null));
+            Assert.IsTrue(list!.Equals((object) list));
             Assert.IsFalse(list.Equals((object) new RepeatedField<string> { "first", "third" }));
             Assert.IsFalse(list.Equals((object) new RepeatedField<string> { "first" }));
             Assert.IsTrue(list.Equals((object) new RepeatedField<string> { "first", "second" }));
@@ -273,7 +273,7 @@ public void Indexer_Set()
             var list = new RepeatedField<string> { "first", "second" };
             list[0] = "changed";
             Assert.AreEqual("changed", list[0]);
-            Assert.Throws<ArgumentNullException>(() => list[0] = null);
+            Assert.Throws<ArgumentNullException>(() => list[0] = null!);
             Assert.Throws<ArgumentOutOfRangeException>(() => list[-1] = "bad");
             Assert.Throws<ArgumentOutOfRangeException>(() => list[2] = "bad");
         }

csharp/src/Google.Protobuf.Test/Compatibility/PropertyInfoExtensionsTest.cs

@@ -37,14 +37,14 @@ namespace Google.Protobuf.Compatibility
 {
     public class PropertyInfoExtensionsTest
     {
-        public string PublicReadWrite { get; set; }
-        private string PrivateReadWrite { get; set; }
-        public string PublicReadPrivateWrite { get; private set; }
-        public string PrivateReadPublicWrite { private get; set; }
-        public string PublicReadOnly { get { return null; } }
-        private string PrivateReadOnly { get { return null; } }
-        public string PublicWriteOnly { set { } }
-        private string PrivateWriteOnly { set {  } }
+        public string? PublicReadWrite { get; set; }
+        private string? PrivateReadWrite { get; set; }
+        public string? PublicReadPrivateWrite { get; private set; }
+        public string? PrivateReadPublicWrite { private get; set; }
+        public string? PublicReadOnly => null;
+        private string? PrivateReadOnly => null;
+        public string? PublicWriteOnly { set { } }
+        private string? PrivateWriteOnly { set {  } }
 
         [Test]
         [TestCase("PublicReadWrite")]

csharp/src/Google.Protobuf.Test/Compatibility/TypeExtensionsTest.cs

@@ -40,8 +40,8 @@ namespace Google.Protobuf.Compatibility
     public class TypeExtensionsTest
     {
         public class DerivedList : List<string> { }
-        public string PublicProperty { get; set; }
-        private string PrivateProperty { get; set; }
+        public string? PublicProperty { get; set; }
+        private string? PrivateProperty { get; set; }
 
         public void PublicMethod()
         {

csharp/src/Google.Protobuf.Test/DeprecatedMemberTest.cs

@@ -41,10 +41,10 @@ namespace Google.Protobuf
 {
     public class DeprecatedMemberTest
     {
-        private static void AssertIsDeprecated(MemberInfo member)
+        private static void AssertIsDeprecated(MemberInfo? member)
         {
             Assert.NotNull(member);
-            Assert.IsTrue(member.IsDefined(typeof(ObsoleteAttribute), false), "Member not obsolete: " + member);
+            Assert.IsTrue(member!.IsDefined(typeof(ObsoleteAttribute), false), "Member not obsolete: " + member);
         }
 
         [Test]

csharp/src/Google.Protobuf.Test/EqualityTester.cs

@@ -49,10 +49,10 @@ public static void AssertEquality<T>(T first, T second) where T : IEquatable<T>
             Assert.AreEqual(first.GetHashCode(), second.GetHashCode());
         }
 
-        public static void AssertInequality<T>(T first, T second, bool checkHashcode = true) where T : IEquatable<T>
+        public static void AssertInequality<T>(T first, T? second, bool checkHashcode = true) where T : IEquatable<T>
         {
-            Assert.IsFalse(first.Equals(second));
-            Assert.IsFalse(first.Equals((object) second));
+            Assert.IsFalse(first.Equals(second!));
+            Assert.IsFalse(first.Equals((object?) second));
             // While this isn't a requirement, the chances of this test failing due to
             // coincidence rather than a bug are very small.
             // For such rare cases, an argument can be used to disable the check.