Fix edge case in GameVersion and refactor

- Test coverage has been added for the entire class, and verbose/redundant code has been refactored
- Fixes JSON serialization: JsonConstructor requires that the ctor parameters match fields/properties of the target class.
Previously, this meant that the JSON constructor would always throw an ArgumentNullException, as `Input` was not a class property.

Dalamud.Test/Game/GameVersionTests.cs

@@ -1,10 +1,71 @@
+using System;
+
 using Dalamud.Common.Game;
+
+using Newtonsoft.Json;
+
 using Xunit;
 
 namespace Dalamud.Test.Game
 {
     public class GameVersionTests
     {
+        [Fact]
+        public void VersionComparisons()
+        {
+            var v1 = GameVersion.Parse("2021.01.01.0000.0000");
+            var v2 = GameVersion.Parse("2021.01.01.0000.0000");
+            Assert.True(v1 == v2);
+            Assert.False(v1 != v2);
+            Assert.False(v1 < v2);
+            Assert.True(v1 <= v2);
+            Assert.False(v1 > v2);
+            Assert.True(v1 >= v2);
+        }
+
+        [Fact]
+        public void VersionAddition()
+        {
+            var v1 = GameVersion.Parse("2021.01.01.0000.0000");
+            var v2 = GameVersion.Parse("2021.01.05.0000.0000");
+            Assert.Equal(v2, v1 + TimeSpan.FromDays(4));
+        }
+
+        [Fact]
+        public void VersionAdditionAny()
+        {
+            Assert.Equal(GameVersion.Any, GameVersion.Any + TimeSpan.FromDays(4));
+        }
+
+        [Fact]
+        public void VersionSubtraction()
+        {
+            var v1 = GameVersion.Parse("2021.01.05.0000.0000");
+            var v2 = GameVersion.Parse("2021.01.01.0000.0000");
+            Assert.Equal(v2, v1 - TimeSpan.FromDays(4));
+        }
+
+        [Fact]
+        public void VersionSubtractionAny()
+        {
+            Assert.Equal(GameVersion.Any, GameVersion.Any - TimeSpan.FromDays(4));
+        }
+
+        [Fact]
+        public void VersionClone()
+        {
+            var v1 = GameVersion.Parse("2021.01.01.0000.0000");
+            var v2 = v1.Clone();
+            Assert.NotSame(v1, v2);
+        }
+
+        [Fact]
+        public void VersionCast()
+        {
+            var v = GameVersion.Parse("2021.01.01.0000.0000");
+            Assert.Equal("2021.01.01.0000.0000", v);
+        }
+
         [Theory]
         [InlineData("any", "any")]
         [InlineData("2021.01.01.0000.0000", "2021.01.01.0000.0000")]
@@ -14,6 +75,18 @@ namespace Dalamud.Test.Game
             var v2 = GameVersion.Parse(ver2);
 
             Assert.Equal(v1, v2);
+            Assert.Equal(0, v1.CompareTo(v2));
+            Assert.Equal(v1.GetHashCode(), v2.GetHashCode());
+        }
+
+        [Fact]
+        public void VersionNullEquality()
+        {
+            // Tests `Equals(GameVersion? value)`
+            Assert.False(GameVersion.Parse("2021.01.01.0000.0000").Equals(null));
+
+            // Tests `Equals(object? value)`
+            Assert.False(GameVersion.Parse("2021.01.01.0000.0000").Equals((object)null));
         }
 
         [Theory]
@@ -31,6 +104,67 @@ namespace Dalamud.Test.Game
             Assert.True(v1.CompareTo(v2) < 0);
         }
 
+        [Theory]
+        [InlineData("any", "2020.06.15.0000.0000")]
+        public void VersionComparisonInverse(string ver1, string ver2)
+        {
+            var v1 = GameVersion.Parse(ver1);
+            var v2 = GameVersion.Parse(ver2);
+
+            Assert.True(v1.CompareTo(v2) > 0);
+        }
+
+        [Fact]
+        public void VersionComparisonNull()
+        {
+            var v = GameVersion.Parse("2020.06.15.0000.0000");
+
+            // Tests `CompareTo(GameVersion? value)`
+            Assert.True(v.CompareTo(null) > 0);
+
+            // Tests `CompareTo(object? value)`
+            Assert.True(v.CompareTo((object)null) > 0);
+        }
+
+        [Fact]
+        public void VersionComparisonBoxed()
+        {
+            var v1 = GameVersion.Parse("2020.06.15.0000.0000");
+            var v2 = GameVersion.Parse("2020.06.15.0000.0000");
+            Assert.Equal(0, v1.CompareTo((object)v2));
+        }
+
+        [Fact]
+        public void VersionComparisonBoxedInvalid()
+        {
+            var v = GameVersion.Parse("2020.06.15.0000.0000");
+            Assert.Throws<ArgumentException>(() => v.CompareTo(42));
+        }
+
+        [Theory]
+        [InlineData("2020.06.15.0000.0000")]
+        [InlineData("2021.01.01.0000")]
+        [InlineData("2021.01.01")]
+        [InlineData("2021.01")]
+        [InlineData("2021")]
+        public void VersionParse(string ver)
+        {
+            var v = GameVersion.Parse(ver);
+            Assert.NotNull(v);
+        }
+
+        [Theory]
+        [InlineData("2020.06.15.0000.0000")]
+        [InlineData("2021.01.01.0000")]
+        [InlineData("2021.01.01")]
+        [InlineData("2021.01")]
+        [InlineData("2021")]
+        public void VersionTryParse(string ver)
+        {
+            Assert.True(GameVersion.TryParse(ver, out var v));
+            Assert.NotNull(v);
+        }
+
         [Theory]
         [InlineData("2020.06.15.0000.0000")]
         [InlineData("2021.01.01.0000")]
@@ -39,9 +173,8 @@ namespace Dalamud.Test.Game
         [InlineData("2021")]
         public void VersionConstructor(string ver)
         {
-            var v = GameVersion.Parse(ver);
-
-            Assert.True(v != null);
+            var v = new GameVersion(ver);
+            Assert.NotNull(v);
         }
 
         [Theory]
@@ -54,5 +187,78 @@ namespace Dalamud.Test.Game
             Assert.False(result);
             Assert.Null(v);
         }
+
+        [Theory]
+        [InlineData("any", "any")]
+        [InlineData("2020.06.15.0000.0000", "2020.06.15.0000.0000")]
+        [InlineData("2021.01.01.0000", "2021.01.01.0000.0000")]
+        [InlineData("2021.01.01", "2021.01.01.0000.0000")]
+        [InlineData("2021.01", "2021.01.00.0000.0000")]
+        [InlineData("2021", "2021.00.00.0000.0000")]
+        public void VersionToString(string ver1, string ver2)
+        {
+            var v1 = GameVersion.Parse(ver1);
+            Assert.Equal(ver2, v1.ToString());
+        }
+
+        [Fact]
+        public void VersionIsSerializationSafe()
+        {
+            var v = GameVersion.Parse("2020.06.15.0000.0000");
+            var serialized = JsonConvert.SerializeObject(v);
+            var deserialized = JsonConvert.DeserializeObject<GameVersion>(serialized);
+            Assert.Equal(v, deserialized);
+        }
+
+        [Fact]
+        public void VersionInvalidDeserialization()
+        {
+            var serialized = """
+                             {
+                                "Year": -1,
+                                "Month": -1,
+                                "Day": -1,
+                                "Major": -1,
+                                "Minor": -1,
+                             }
+                             """;
+            Assert.Throws<ArgumentOutOfRangeException>(() => JsonConvert.DeserializeObject<GameVersion>(serialized));
+        }
+
+        [Fact]
+        public void VersionConstructorNegativeYear()
+        {
+            Assert.Throws<ArgumentOutOfRangeException>(() => new GameVersion(-2024));
+        }
+
+        [Fact]
+        public void VersionConstructorNegativeMonth()
+        {
+            Assert.Throws<ArgumentOutOfRangeException>(() => new GameVersion(2024, -3));
+        }
+
+        [Fact]
+        public void VersionConstructorNegativeDay()
+        {
+            Assert.Throws<ArgumentOutOfRangeException>(() => new GameVersion(2024, 3, -13));
+        }
+
+        [Fact]
+        public void VersionConstructorNegativeMajor()
+        {
+            Assert.Throws<ArgumentOutOfRangeException>(() => new GameVersion(2024, 3, 13, -1));
+        }
+
+        [Fact]
+        public void VersionConstructorNegativeMinor()
+        {
+            Assert.Throws<ArgumentOutOfRangeException>(() => new GameVersion(2024, 3, 13, 0, -1));
+        }
+
+        [Fact]
+        public void VersionParseNull()
+        {
+            Assert.Throws<ArgumentNullException>(() => GameVersion.Parse(null!));
+        }
     }
 }