Improve Gas Yaml Serialization (#40070)

* Make yaml gas serialization cleaner

* fix exception

* fix validation code

* rudimentary test & permissive loading

* change it a bit

* Test fixes and adjustments

Content.Shared/Atmos/GasArraySerializer.cs

@@ -0,0 +1,105 @@
+using Robust.Shared.Serialization;
+using Robust.Shared.Serialization.Manager;
+using Robust.Shared.Serialization.Markdown;
+using Robust.Shared.Serialization.Markdown.Mapping;
+using Robust.Shared.Serialization.Markdown.Sequence;
+using Robust.Shared.Serialization.Markdown.Validation;
+using Robust.Shared.Serialization.TypeSerializers.Interfaces;
+
+namespace Content.Shared.Atmos;
+
+public sealed class GasArraySerializer : ITypeSerializer<float[], SequenceDataNode>, ITypeSerializer<float[], MappingDataNode>
+{
+    public ValidationNode Validate(ISerializationManager serializationManager,
+        SequenceDataNode node,
+        IDependencyCollection dependencies,
+        ISerializationContext? context = null)
+    {
+        var list = new List<ValidationNode>();
+
+        foreach (var elem in node.Sequence)
+        {
+            list.Add(serializationManager.ValidateNode<float>(elem, context));
+        }
+
+        return new ValidatedSequenceNode(list);
+    }
+
+    public float[] Read(ISerializationManager serializationManager,
+        SequenceDataNode node,
+        IDependencyCollection dependencies,
+        SerializationHookContext hookCtx,
+        ISerializationContext? context = null,
+        ISerializationManager.InstantiationDelegate<float[]>? instanceProvider = null)
+    {
+        var list = instanceProvider != null ? instanceProvider() : new float[Atmospherics.AdjustedNumberOfGases];
+
+        for (var i = 0; i < node.Sequence.Count; i++)
+        {
+            list[i] = serializationManager.Read<float>(node.Sequence[i], hookCtx, context);
+        }
+
+        return list;
+    }
+
+    public ValidationNode Validate(ISerializationManager serializationManager,
+        MappingDataNode node,
+        IDependencyCollection dependencies,
+        ISerializationContext? context = null)
+    {
+        var dict = new Dictionary<ValidationNode, ValidationNode>();
+
+        foreach (var (key, value) in node.Children)
+        {
+            ValidationNode keyNode = Enum.TryParse<Gas>(key, out _)
+                ? new ValidatedValueNode(node.GetKeyNode(key))
+                : new ErrorNode(node.GetKeyNode(key), $"Failed to parse Gas: {key}");
+
+            dict.Add(keyNode, serializationManager.ValidateNode<float>(value, context));
+        }
+
+        return new ValidatedMappingNode(dict);
+    }
+
+    public float[] Read(ISerializationManager serializationManager,
+        MappingDataNode node,
+        IDependencyCollection dependencies,
+        SerializationHookContext hookCtx,
+        ISerializationContext? context = null,
+        ISerializationManager.InstantiationDelegate<float[]>? instanceProvider = null)
+    {
+        var list = instanceProvider != null ? instanceProvider() : new float[Atmospherics.AdjustedNumberOfGases];
+
+        foreach (var (gas, value) in node.Children)
+        {
+            // In the event that an invalid gas got serialized into something,
+            // we simply ignore it and continue reading.
+            // Errors should already be caught by Validate().
+            if (!Enum.TryParse<Gas>(gas, out var gasEnum))
+                continue;
+
+            list[(int)gasEnum] = serializationManager.Read<float>(value, hookCtx, context);
+        }
+
+        return list;
+    }
+
+    public DataNode Write(ISerializationManager serializationManager,
+        float[] value,
+        IDependencyCollection dependencies,
+        bool alwaysWrite = false,
+        ISerializationContext? context = null)
+    {
+        var mapping = new MappingDataNode();
+
+        for (var i = 0; i < Atmospherics.TotalNumberOfGases; i++)
+        {
+            if (value[i] <= 0)
+                continue;
+
+            mapping.Add(((Gas) i).ToString(), serializationManager.WriteValue(value[i], alwaysWrite, context));
+        }
+
+        return mapping;
+    }
+}