fix: Do not report a permanent data source failure as fatal

src/LaunchDarkly.OpenFeature.ServerProvider/Provider.cs

@@ -214,9 +214,9 @@ private void StatusChangeHandler(object sender, DataSourceStatus status)
                     break;
                 case DataSourceState.Off:
                 default:
-                    // If we had initialized every, then we could still initialize flags, but I think we need to let
-                    // a consumer know we have encountered an unrecoverable problem with the connection.
-                    _statusProvider.SetStatus(ProviderStatus.Fatal, ProviderShutdownMessage);
+                    // The status is an error, and not fatal, because the LaunchDarkly client can continue to
+                    // evaluate flags using the data it already has.
+                    _statusProvider.SetStatus(ProviderStatus.Error, ProviderShutdownMessage);
                     _initCompletion.TrySetException(new LaunchDarklyProviderInitException(ProviderShutdownMessage));
                     break;
             }

test/LaunchDarkly.OpenFeature.ServerProvider.Tests/ClientIntegrationTests.cs

@@ -119,6 +119,39 @@ public async Task ItHandlesFailedInitialization()
             Thread.Sleep(100);
             Assert.Equal(1, errorCount);
         }
+
+        [Fact(Timeout = 5000)]
+        public async Task ItCanEvaluateFlagsAfterTheDataSourceHasBeenShutdown()
+        {
+            var mockClient = new Mock<ILdClient>();
+            mockClient.Setup(l => l.GetLogger())
+                .Returns(Components.NoLogging.Build(null).LogAdapter.Logger(null));
+            mockClient.Setup(l => l.Initialized).Returns(true);
+            mockClient.Setup(l => l.BoolVariationDetail("the-flag", It.IsAny<Sdk.Context>(), false))
+                .Returns(new Sdk.EvaluationDetail<bool>(true, 10, Sdk.EvaluationReason.FallthroughReason));
+
+            var mockDataSourceStatus = new Mock<IDataSourceStatusProvider>();
+            mockDataSourceStatus.Setup(l => l.Status).Returns(new DataSourceStatus
+            {
+                State = DataSourceState.Valid
+            });
+            mockClient.Setup(l => l.DataSourceStatusProvider).Returns(mockDataSourceStatus.Object);
+
+            var mockFlagTracker = new Mock<IFlagTracker>();
+            mockClient.Setup(l => l.FlagTracker).Returns(mockFlagTracker.Object);
+
+            var provider = new Provider(mockClient.Object);
+            await Api.Instance.SetProviderAsync(provider);
+
+            mockDataSourceStatus.Raise(e => e.StatusChanged += null,
+                mockDataSourceStatus.Object,
+                new DataSourceStatus { State = DataSourceState.Off });
+            Thread.Sleep(100);
+
+            var client = Api.Instance.GetClient();
+            Assert.True(await client.GetBooleanValueAsync("the-flag", false,
+                EvaluationContext.Builder().Set("targetingKey", "the-key").Build()));
+        }
 #endif
     }
 }