Implement Stucture with JSON string

Author: luizbon

Diff for: src/OpenFeature.Contrib.ConfigCat/ConfigCatProvider.cs

@@ -58,10 +58,12 @@ public override Task<ResolutionDetails<double>> ResolveDoubleValue(string flagKe
         }
 
         /// <inheritdoc/>
-        public override Task<ResolutionDetails<Value>> ResolveStructureValue(string flagKey, Value defaultValue, EvaluationContext context = null)
+        public override async Task<ResolutionDetails<Value>> ResolveStructureValue(string flagKey, Value defaultValue, EvaluationContext context = null)
         {
-            throw new NotSupportedException(
-                "ConfigCat does not support structure values. Use JSON string instead.");
+            var stringDefaultValue = defaultValue?.AsString;
+            var result = await ProcessFlag(flagKey, context, stringDefaultValue);
+            var returnValue = result.Value == null ? defaultValue : new Value(result.Value);
+            return new ResolutionDetails<Value>(flagKey, returnValue, variant: result.Variant, errorMessage: result.ErrorMessage);
         }
 
         private async Task<ResolutionDetails<T>> ProcessFlag<T>(string flagKey, EvaluationContext context, T defaultValue)

Diff for: test/OpenFeature.Contrib.ConfigCat.Test/ConfigCatProviderTest.cs

@@ -59,6 +59,22 @@ public Task GetIntValue_ForFeature_ReturnExpectedResult(object value, int defaul
             return ExecuteResolveTest(value, defaultValue, expectedValue, expectedErrorType, sdkKey, (provider, key, def) => provider.ResolveIntegerValue(key, def));
         }
 
+        [Theory]
+        [AutoData]
+        public async Task GetStructureValue_ForFeature_ReturnExpectedResult(string sdkKey)
+        {
+            const string jsonValue = "{ \"key\": \"value\" }";
+            var defaultValue = new Value(jsonValue);
+            var configCatProvider = new ConfigCatProvider(sdkKey,
+                options => { options.FlagOverrides = BuildFlagOverrides(("example-feature", defaultValue)); });
+
+            var result = await configCatProvider.ResolveStructureValue( "example-feature", defaultValue);
+
+            Assert.Equal(defaultValue.AsString, result.Value.AsString);
+            Assert.Equal("example-feature", result.FlagKey);
+            Assert.Equal(ErrorType.None, result.ErrorType);
+        }
+
         private static async Task ExecuteResolveTest<T>(object value, T defaultValue, T expectedValue, ErrorType expectedErrorType, string sdkKey, Func<ConfigCatProvider, string, T, Task<ResolutionDetails<T>>> resolveFunc)
         {
             var configCatProvider = new ConfigCatProvider(sdkKey,