enable nullable annotations for most of the SMAPI toolkit (#837)

4 files changed, 23 insertions, 29 deletions

diff --git a/src/SMAPI.Toolkit/Serialization/Converters/ManifestContentPackForConverter.cs b/src/SMAPI.Toolkit/Serialization/Converters/ManifestContentPackForConverter.cs
index d2dc0d22..faaeedea 100644
--- a/src/SMAPI.Toolkit/Serialization/Converters/ManifestContentPackForConverter.cs
+++ b/src/SMAPI.Toolkit/Serialization/Converters/ManifestContentPackForConverter.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using Newtonsoft.Json;
 using StardewModdingAPI.Toolkit.Serialization.Models;
@@ -35,7 +33,7 @@ namespace StardewModdingAPI.Toolkit.Serialization.Converters
         /// <param name="objectType">The object type.</param>
         /// <param name="existingValue">The object being read.</param>
         /// <param name="serializer">The calling serializer.</param>
-        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+        public override object? ReadJson(JsonReader reader, Type objectType, object? existingValue, JsonSerializer serializer)
         {
             return serializer.Deserialize<ManifestContentPackFor>(reader);
         }
@@ -44,7 +42,7 @@ namespace StardewModdingAPI.Toolkit.Serialization.Converters
         /// <param name="writer">The JSON writer.</param>
         /// <param name="value">The value.</param>
         /// <param name="serializer">The calling serializer.</param>
-        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+        public override void WriteJson(JsonWriter writer, object? value, JsonSerializer serializer)
         {
             throw new InvalidOperationException("This converter does not write JSON.");
         }
diff --git a/src/SMAPI.Toolkit/Serialization/Converters/ManifestDependencyArrayConverter.cs b/src/SMAPI.Toolkit/Serialization/Converters/ManifestDependencyArrayConverter.cs
index 2c3c2ee7..c499a2c6 100644
--- a/src/SMAPI.Toolkit/Serialization/Converters/ManifestDependencyArrayConverter.cs
+++ b/src/SMAPI.Toolkit/Serialization/Converters/ManifestDependencyArrayConverter.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using Newtonsoft.Json;
@@ -37,13 +35,13 @@ namespace StardewModdingAPI.Toolkit.Serialization.Converters
         /// <param name="objectType">The object type.</param>
         /// <param name="existingValue">The object being read.</param>
         /// <param name="serializer">The calling serializer.</param>
-        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+        public override object ReadJson(JsonReader reader, Type objectType, object? existingValue, JsonSerializer serializer)
         {
             List<ManifestDependency> result = new List<ManifestDependency>();
             foreach (JObject obj in JArray.Load(reader).Children<JObject>())
             {
-                string uniqueID = obj.ValueIgnoreCase<string>(nameof(ManifestDependency.UniqueID));
-                string minVersion = obj.ValueIgnoreCase<string>(nameof(ManifestDependency.MinimumVersion));
+                string uniqueID = obj.ValueIgnoreCase<string>(nameof(ManifestDependency.UniqueID))!; // will be validated separately if null
+                string? minVersion = obj.ValueIgnoreCase<string>(nameof(ManifestDependency.MinimumVersion));
                 bool required = obj.ValueIgnoreCase<bool?>(nameof(ManifestDependency.IsRequired)) ?? true;
                 result.Add(new ManifestDependency(uniqueID, minVersion, required));
             }
@@ -54,7 +52,7 @@ namespace StardewModdingAPI.Toolkit.Serialization.Converters
         /// <param name="writer">The JSON writer.</param>
         /// <param name="value">The value.</param>
         /// <param name="serializer">The calling serializer.</param>
-        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+        public override void WriteJson(JsonWriter writer, object? value, JsonSerializer serializer)
         {
             throw new InvalidOperationException("This converter does not write JSON.");
         }
diff --git a/src/SMAPI.Toolkit/Serialization/Converters/SemanticVersionConverter.cs b/src/SMAPI.Toolkit/Serialization/Converters/SemanticVersionConverter.cs
index 9205cebe..c32c3185 100644
--- a/src/SMAPI.Toolkit/Serialization/Converters/SemanticVersionConverter.cs
+++ b/src/SMAPI.Toolkit/Serialization/Converters/SemanticVersionConverter.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
@@ -41,15 +39,17 @@ namespace StardewModdingAPI.Toolkit.Serialization.Converters
         /// <param name="objectType">The object type.</param>
         /// <param name="existingValue">The object being read.</param>
         /// <param name="serializer">The calling serializer.</param>
-        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+        public override object? ReadJson(JsonReader reader, Type objectType, object? existingValue, JsonSerializer serializer)
         {
             string path = reader.Path;
             switch (reader.TokenType)
             {
                 case JsonToken.StartObject:
                     return this.ReadObject(JObject.Load(reader));
+
                 case JsonToken.String:
                     return this.ReadString(JToken.Load(reader).Value<string>(), path);
+
                 default:
                     throw new SParseException($"Can't parse {nameof(ISemanticVersion)} from {reader.TokenType} node (path: {reader.Path}).");
             }
@@ -59,7 +59,7 @@ namespace StardewModdingAPI.Toolkit.Serialization.Converters
         /// <param name="writer">The JSON writer.</param>
         /// <param name="value">The value.</param>
         /// <param name="serializer">The calling serializer.</param>
-        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+        public override void WriteJson(JsonWriter writer, object? value, JsonSerializer serializer)
         {
             writer.WriteValue(value?.ToString());
         }
@@ -75,7 +75,7 @@ namespace StardewModdingAPI.Toolkit.Serialization.Converters
             int major = obj.ValueIgnoreCase<int>(nameof(ISemanticVersion.MajorVersion));
             int minor = obj.ValueIgnoreCase<int>(nameof(ISemanticVersion.MinorVersion));
             int patch = obj.ValueIgnoreCase<int>(nameof(ISemanticVersion.PatchVersion));
-            string prereleaseTag = obj.ValueIgnoreCase<string>(nameof(ISemanticVersion.PrereleaseTag));
+            string? prereleaseTag = obj.ValueIgnoreCase<string>(nameof(ISemanticVersion.PrereleaseTag));
 
             return new SemanticVersion(major, minor, patch, prereleaseTag: prereleaseTag);
         }
@@ -83,11 +83,11 @@ namespace StardewModdingAPI.Toolkit.Serialization.Converters
         /// <summary>Read a JSON string.</summary>
         /// <param name="str">The JSON string value.</param>
         /// <param name="path">The path to the current JSON node.</param>
-        private ISemanticVersion ReadString(string str, string path)
+        private ISemanticVersion? ReadString(string str, string path)
         {
             if (string.IsNullOrWhiteSpace(str))
                 return null;
-            if (!SemanticVersion.TryParse(str, allowNonStandard: this.AllowNonStandard, out ISemanticVersion version))
+            if (!SemanticVersion.TryParse(str, allowNonStandard: this.AllowNonStandard, out ISemanticVersion? version))
                 throw new SParseException($"Can't parse semantic version from invalid value '{str}', should be formatted like 1.2, 1.2.30, or 1.2.30-beta (path: {path}).");
             return version;
         }
diff --git a/src/SMAPI.Toolkit/Serialization/Converters/SimpleReadOnlyConverter.cs b/src/SMAPI.Toolkit/Serialization/Converters/SimpleReadOnlyConverter.cs
index c923350c..1c59f5e7 100644
--- a/src/SMAPI.Toolkit/Serialization/Converters/SimpleReadOnlyConverter.cs
+++ b/src/SMAPI.Toolkit/Serialization/Converters/SimpleReadOnlyConverter.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
@@ -27,21 +25,12 @@ namespace StardewModdingAPI.Toolkit.Serialization.Converters
             return objectType == typeof(T) || Nullable.GetUnderlyingType(objectType) == typeof(T);
         }
 
-        /// <summary>Writes the JSON representation of the object.</summary>
-        /// <param name="writer">The JSON writer.</param>
-        /// <param name="value">The value.</param>
-        /// <param name="serializer">The calling serializer.</param>
-        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
-        {
-            throw new InvalidOperationException("This converter does not write JSON.");
-        }
-
         /// <summary>Reads the JSON representation of the object.</summary>
         /// <param name="reader">The JSON reader.</param>
         /// <param name="objectType">The object type.</param>
         /// <param name="existingValue">The object being read.</param>
         /// <param name="serializer">The calling serializer.</param>
-        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+        public override object? ReadJson(JsonReader reader, Type objectType, object? existingValue, JsonSerializer serializer)
         {
             string path = reader.Path;
             switch (reader.TokenType)
@@ -60,6 +49,15 @@ namespace StardewModdingAPI.Toolkit.Serialization.Converters
             }
         }
 
+        /// <summary>Writes the JSON representation of the object.</summary>
+        /// <param name="writer">The JSON writer.</param>
+        /// <param name="value">The value.</param>
+        /// <param name="serializer">The calling serializer.</param>
+        public override void WriteJson(JsonWriter writer, object? value, JsonSerializer serializer)
+        {
+            throw new InvalidOperationException("This converter does not write JSON.");
+        }
+
 
         /*********
         ** Protected methods