1 files changed, 88 insertions, 0 deletions
diff --git a/src/StardewModdingAPI.Toolkit/Serialisation/Converters/SemanticVersionConverter.cs b/src/StardewModdingAPI.Toolkit/Serialisation/Converters/SemanticVersionConverter.cs
new file mode 100644
index 00000000..9b2f5e7d
--- /dev/null
+++ b/src/StardewModdingAPI.Toolkit/Serialisation/Converters/SemanticVersionConverter.cs
@@ -0,0 +1,88 @@
+using System;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+
+namespace StardewModdingAPI.Toolkit.Serialisation.Converters
+{
+    /// <summary>Handles deserialisation of <see cref="ISemanticVersion"/>.</summary>
+    internal class SemanticVersionConverter : JsonConverter
+    {
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>Get whether this converter can read JSON.</summary>
+        public override bool CanRead => true;
+
+        /// <summary>Get whether this converter can write JSON.</summary>
+        public override bool CanWrite => true;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Get whether this instance can convert the specified object type.</summary>
+        /// <param name="objectType">The object type.</param>
+        public override bool CanConvert(Type objectType)
+        {
+            return typeof(ISemanticVersion).IsAssignableFrom(objectType);
+        }
+
+        /// <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)
+        {
+            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($"Can't parse {nameof(ISemanticVersion)} from {reader.TokenType} node (path: {reader.Path}).");
+            }
+        }
+
+        /// <summary>Writes the JSON representation of the object.</summary>
+        /// <param name="writer">The JSON writer.</param>
+        /// <param name="value">The value.</param>
+        /// <param name="serializer">The calling serializer.</param>
+        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+        {
+            writer.WriteValue(value?.ToString());
+        }
+
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>Read a JSON object.</summary>
+        /// <param name="obj">The JSON object to read.</param>
+        private ISemanticVersion ReadObject(JObject obj)
+        {
+            int major = obj.ValueIgnoreCase<int>("MajorVersion");
+            int minor = obj.ValueIgnoreCase<int>("MinorVersion");
+            int patch = obj.ValueIgnoreCase<int>("PatchVersion");
+            string build = obj.ValueIgnoreCase<string>("Build");
+            if (build == "0")
+                build = null; // '0' from incorrect examples in old SMAPI documentation
+
+            return new SemanticVersion(major, minor, patch, build);
+        }
+
+        /// <summary>Read a JSON string.</summary>
+        /// <param name="str">The JSON string value.</param>
+        /// <param name="path">The path to the current JSON node.</param>
+        private ISemanticVersion ReadString(string str, string path)
+        {
+            if (string.IsNullOrWhiteSpace(str))
+                return null;
+            if (!SemanticVersion.TryParse(str, out ISemanticVersion version))
+                throw new SParseException($"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 (SemanticVersion)version;
+        }
+    }
+}