Implement JSON assignment type (FF-999)

dot-net-sdk/EppoClient.cs

@@ -6,6 +6,7 @@
 using eppo_sdk.store;
 using eppo_sdk.tasks;
 using eppo_sdk.validators;
+using Newtonsoft.Json.Linq;
 using NLog;
 
 namespace eppo_sdk;
@@ -29,6 +30,11 @@ private EppoClient(ConfigurationStore configurationStore, EppoClientConfig eppoC
         _fetchExperimentsTask = fetchExperimentsTask;
     }
 
+    public JObject? GetJsonAssignment(string subjectKey, string flagKey, SubjectAttributes? subjectAttributes = null)
+    {
+        return GetAssignment(subjectKey, flagKey, subjectAttributes ?? new SubjectAttributes())?.JsonValue();
+    }
+
     public bool? GetBoolAssignment(string subjectKey, string flagKey, SubjectAttributes? subjectAttributes = null)
     {
         return GetAssignment(subjectKey, flagKey, subjectAttributes ?? new SubjectAttributes())?.BoolValue();
@@ -40,7 +46,7 @@ private EppoClient(ConfigurationStore configurationStore, EppoClientConfig eppoC
     }
 
 
-    public int? GetIntegerAssignment(string subjectKey, string flagKey, SubjectAttributes? subjectAttributes = null)
+    public long? GetIntegerAssignment(string subjectKey, string flagKey, SubjectAttributes? subjectAttributes = null)
     {
         return GetAssignment(subjectKey, flagKey, subjectAttributes ?? new SubjectAttributes())?.IntegerValue();
     }
@@ -52,7 +58,7 @@ private EppoClient(ConfigurationStore configurationStore, EppoClientConfig eppoC
     }
 
 
-    private EppoValue? GetAssignment(string subjectKey, string flagKey, SubjectAttributes subjectAttributes)
+    private HasEppoValue? GetAssignment(string subjectKey, string flagKey, SubjectAttributes subjectAttributes)
     {
         InputValidator.ValidateNotBlank(subjectKey, "Invalid argument: subjectKey cannot be blank");
         InputValidator.ValidateNotBlank(flagKey, "Invalid argument: flagKey cannot be blank");
@@ -93,23 +99,26 @@ private EppoClient(ConfigurationStore configurationStore, EppoClientConfig eppoC
 
         var assignedVariation =
             GetAssignedVariation(subjectKey, flagKey, configuration.subjectShards, allocation.variations);
-        try
-        {
-            _eppoClientConfig.AssignmentLogger
-                .LogAssignment(new AssignmentLogData(
-                    flagKey,
-                    rule.allocationKey,
-                    assignedVariation.typedValue.StringValue(),
-                    subjectKey,
-                    subjectAttributes
-                ));
-        }
-        catch (Exception)
+        if (assignedVariation != null && !assignedVariation.IsNull())
         {
-            // Ignore Exception
+            try
+            {
+                _eppoClientConfig.AssignmentLogger
+                    .LogAssignment(new AssignmentLogData(
+                        flagKey,
+                        rule.allocationKey,
+                        assignedVariation.StringValue() ?? "null",
+                        subjectKey,
+                        subjectAttributes
+                    ));
+            }
+            catch (Exception)
+            {
+                // Ignore Exception
+            }
         }
 
-        return assignedVariation?.typedValue;
+        return assignedVariation;
     }
 
     private bool IsInExperimentSample(string subjectKey, string flagKey, int subjectShards,
@@ -126,10 +135,10 @@ private Variation GetAssignedVariation(string subjectKey, string flagKey, int su
         return variations.Find(config => Shard.IsInRange(shard, config.shardRange))!;
     }
 
-    public EppoValue GetSubjectVariationOverride(string subjectKey, ExperimentConfiguration experimentConfiguration)
+    public HasEppoValue GetSubjectVariationOverride(string subjectKey, ExperimentConfiguration experimentConfiguration)
     {
         var hexedSubjectKey = Shard.GetHex(subjectKey);
-        return experimentConfiguration.typedOverrides.GetValueOrDefault(hexedSubjectKey, new EppoValue());
+        return new HasEppoValue(experimentConfiguration.typedOverrides.GetValueOrDefault(hexedSubjectKey, null));
     }
 
     public static EppoClient Init(EppoClientConfig eppoClientConfig)

dot-net-sdk/dto/Condition.cs

@@ -3,16 +3,15 @@
 
 namespace eppo_sdk.dto;
 
-public class Condition
+public class Condition : HasEppoValue
 {
     public string attribute { get; set; }
-    public EppoValue value { get; set; }
 
     [JsonProperty(PropertyName = "operator", NamingStrategyType = typeof(DefaultNamingStrategy))]
     public OperatorType operatorType { get; set; }
 
     public override string ToString()
     {
-        return $"operator: {operatorType} | Attribute: {attribute} | value: {value}";
+        return $"operator: {operatorType} | Attribute: {attribute} | value: {Value}";
     }
-}
+}

dot-net-sdk/dto/EppoValueType.cs

@@ -7,5 +7,6 @@ public enum EppoValueType
     STRING,
     BOOLEAN,
     NULL,
-    ARRAY_OF_STRING
+    ARRAY_OF_STRING, 
+    JSON
 }

dot-net-sdk/dto/ExperimentConfiguration.cs

@@ -2,16 +2,16 @@
 
 public class ExperimentConfiguration
 {
     public string name { get; set; }
     public bool enabled { get; set; }
     public int subjectShards { get; set; }
-    public Dictionary<string, EppoValue> typedOverrides { get; set; }
+    public Dictionary<string, Object> typedOverrides { get; set; }
     public Dictionary<string, Allocation> allocations { get; set; }
     public List<Rule> rules { get; set; }
 
     public Allocation? GetAllocation(string allocationKey)
     {
         allocations.TryGetValue(allocationKey, out var value);
         return value;
     }
-}
+}

dot-net-sdk/dto/HasEppoValue.cs

@@ -0,0 +1,140 @@
+using System.Globalization;
+using System.Numerics;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+using NLog;
+
+namespace eppo_sdk.dto;
+
+
+public class HasEppoValue
+{
+
+    private static readonly Logger Logger = LogManager.GetCurrentClassLogger();
+
+    private bool _typed;
+
+    private Object? _value;
+    public Object? Value
+    {
+        get { return _value; }
+        set
+        {
+            if (!_typed)
+            {
+                _type = InferTypeFromValue(value);
+                _value = value;
+            }
+        }
+    }
+    public Object? typedValue
+    {
+        get { return _value; }
+        set
+        {
+            _typed = true;
+            _type = InferTypeFromValue(value);
+            _value = value;
+        }
+    }
+    private EppoValueType _type;
+    public EppoValueType Type { get { return _type; } }
+
+    public bool? BoolValue() => _value != null ? (bool)_value : null;
+    public double? DoubleValue() => Convert.ToDouble(_value);
+    public long? IntegerValue() => _value != null ? (long)_value : null;
+    public string? StringValue() => _value != null ? (string)_value : null;
+    public List<string>? ArrayValue()
+    {
+        if (_value == null)
+        {
+            return null;
+        }
+
+        if (_value is JArray array)
+        {
+
+            return new List<string>(array.ToObject<string[]>());
+        }
+        return (List<string>)_value;
+    }
+    public JObject? JsonValue() => _value == null ? null : (JObject)_value;
+
+
+
+    private static EppoValueType InferTypeFromValue(Object? value)
+    {
+        if (value == null) return EppoValueType.NULL;
+
+        if (value is Array || value.GetType().IsArray || value is JArray || value is List<string> || value is IEnumerable<string>)
+        {
+            return EppoValueType.ARRAY_OF_STRING;
+        }
+        else if (value is bool || value is Boolean)
+        {
+            return EppoValueType.BOOLEAN;
+        }
+        else if (value is float || value is double || value is Double || value is float)
+        {
+            return EppoValueType.NUMBER;
+
+        }
+        else if (value is int || value is long || value is BigInteger)
+        {
+            return EppoValueType.INTEGER;
+
+        }
+        else if (value is string || value is String)
+        {
+            return EppoValueType.STRING;
+        }
+        else if (value is JObject)
+        {
+            return EppoValueType.JSON;
+        }
+        else
+        {
+            Type type = value!.GetType();
+            Logger.Error($"Unexpected value of type {type}");
+            Console.WriteLine($"Unexpected value of type {type}");
+            return EppoValueType.NULL;
+        }
+    }
+
+    public static HasEppoValue Bool(string? value) => new(value, EppoValueType.BOOLEAN);
+    public static HasEppoValue Bool(bool value) => new(value, EppoValueType.BOOLEAN);
+    public static HasEppoValue Number(string value) => new(value, EppoValueType.NUMBER);
+    public static HasEppoValue String(string? value) => new(value, EppoValueType.STRING);
+    public static HasEppoValue Integer(string value) => new(value, EppoValueType.INTEGER);
+    public static HasEppoValue Null() => new();
+
+    public HasEppoValue()
+    {
+    }
+
+    public HasEppoValue(object? value, EppoValueType type)
+    {
+        this.Value = value;
+    }
+
+    [JsonConstructor]
+    public HasEppoValue(object? value)
+    {
+        this.Value = value;
+    }
+
+    public HasEppoValue(List<string> array)
+    {
+        this.Value = array;
+    }
+
+    public bool IsNumeric() => _type == EppoValueType.NUMBER || _type == EppoValueType.INTEGER;
+
+    public bool IsNull() => EppoValueType.NULL.Equals(Type);
+
+    public static bool IsNullValue(HasEppoValue? value) =>
+     value == null /* null pointer */ ||
+         value.IsNull() /* parsed as a null JSON token type */ ||
+         value.Value == null; /* Value type is set but value is null */
+
+}

dot-net-sdk/dto/SubjectAttributes.cs

@@ -1,6 +1,6 @@
 namespace eppo_sdk.dto;
 
-public class SubjectAttributes: Dictionary<string, EppoValue>
+public class SubjectAttributes: Dictionary<string, Object>
 {
 
 }