Made ConsulConfigurationProvider.Dispose idempotent (#99)

Author: jamarino

src/Winton.Extensions.Configuration.Consul/ConsulConfigurationProvider.cs

@@ -27,6 +27,7 @@ internal sealed class ConsulConfigurationProvider : ConfigurationProvider, IDisp
         private readonly IConsulConfigurationSource _source;
         private ulong _lastIndex;
         private Task? _pollTask;
+        private bool _disposed;
 
         public ConsulConfigurationProvider(
             IConsulConfigurationSource source,
@@ -44,8 +45,14 @@ public ConsulConfigurationProvider(
 
         public void Dispose()
         {
+            if (_disposed)
+            {
+                return;
+            }
+
             _cancellationTokenSource.Cancel();
             _cancellationTokenSource.Dispose();
+            _disposed = true;
         }
 
         public override void Load()

test/Winton.Extensions.Configuration.Consul.Test/ConsulConfigurationProviderTests.cs

@@ -112,6 +112,23 @@ private async Task ShouldCancelPollingTaskWhenReloading()
                     kv => kv.List("Test", It.IsAny<QueryOptions>(), It.IsAny<CancellationToken>()),
                     Times.Between(expectedKvCalls, expectedKvCalls + 1, Range.Inclusive));
             }
+
+            [Fact]
+            private void ShouldNotThrowOnMultipleDisposeCalls()
+            {
+                _source.ReloadOnChange = true;
+                _source.Optional = true;
+                _kvEndpoint
+                    .Setup(kv => kv.List("Test", It.IsAny<QueryOptions>(), It.IsAny<CancellationToken>()))
+                    .ReturnsAsync(new QueryResult<KVPair[]> { StatusCode = HttpStatusCode.OK });
+
+                _provider.Load();
+                _provider.Dispose();
+
+                var secondDispose = _provider.Invoking(p => p.Dispose());
+
+                secondDispose.Should().NotThrow();
+            }
         }
 
         public sealed class DoNotReloadOnChange : ConsulConfigurationProviderTests