Add IsCosmos extension method.

src/EFCore.Cosmos/Extensions/CosmosDatabaseFacadeExtensions.cs

@@ -2,8 +2,10 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Reflection;
 using JetBrains.Annotations;
 using Microsoft.Azure.Cosmos;
+using Microsoft.EntityFrameworkCore.Cosmos.Infrastructure.Internal;
 using Microsoft.EntityFrameworkCore.Cosmos.Internal;
 using Microsoft.EntityFrameworkCore.Cosmos.Storage.Internal;
 using Microsoft.EntityFrameworkCore.Infrastructure;
@@ -39,5 +41,23 @@ private static TService GetService<TService>(IInfrastructure<IServiceProvider> d
 
             return service;
         }
+
+        /// <summary>
+        ///     <para>
+        ///         Returns <c>true</c> if the database provider currently in use is the Cosmos provider.
+        ///     </para>
+        ///     <para>
+        ///         This method can only be used after the <see cref="DbContext" /> has been configured because
+        ///         it is only then that the provider is known. This means that this method cannot be used
+        ///         in <see cref="DbContext.OnConfiguring" /> because this is where application code sets the
+        ///         provider to use as part of configuring the context.
+        ///     </para>
+        /// </summary>
+        /// <param name="database"> The facade from <see cref="DbContext.Database" />. </param>
+        /// <returns> <c>true</c> if the Cosmos provider is being used. </returns>
+        public static bool IsCosmos([NotNull] this DatabaseFacade database)
+            => database.ProviderName.Equals(
+                typeof(CosmosOptionsExtension).GetTypeInfo().Assembly.GetName().Name,
+                StringComparison.Ordinal);
     }
 }

src/EFCore.Cosmos/Extensions/CosmosDbContextOptionsExtensions.cs

@@ -39,8 +39,8 @@ public static DbContextOptionsBuilder UseCosmos(
             Check.NotEmpty(authKeyOrResourceToken, nameof(authKeyOrResourceToken));
             Check.NotEmpty(databaseName, nameof(databaseName));
 
-            var extension = optionsBuilder.Options.FindExtension<CosmosDbOptionsExtension>()
-                            ?? new CosmosDbOptionsExtension();
+            var extension = optionsBuilder.Options.FindExtension<CosmosOptionsExtension>()
+                            ?? new CosmosOptionsExtension();
 
             extension = extension
                 .WithServiceEndPoint(serviceEndPoint)

src/EFCore.Cosmos/Extensions/CosmosServiceCollectionExtensions.cs

@@ -30,7 +30,7 @@ public static IServiceCollection AddEntityFrameworkCosmos([NotNull] this IServic
 
             var builder = new EntityFrameworkServicesBuilder(serviceCollection)
                 .TryAdd<LoggingDefinitions, CosmosLoggingDefinitions>()
-                .TryAdd<IDatabaseProvider, DatabaseProvider<CosmosDbOptionsExtension>>()
+                .TryAdd<IDatabaseProvider, DatabaseProvider<CosmosOptionsExtension>>()
                 .TryAdd<IDatabase, CosmosDatabaseWrapper>()
                 .TryAdd<IExecutionStrategyFactory, CosmosExecutionStrategyFactory>()
                 .TryAdd<IDbContextTransactionManager, CosmosTransactionManager>()

src/EFCore.Cosmos/Infrastructure/CosmosDbContextOptionsBuilder.cs

@@ -43,10 +43,10 @@ public virtual CosmosDbContextOptionsBuilder Region(string region)
         /// </summary>
         /// <param name="setAction"> An action to set the option. </param>
         /// <returns> The same builder instance so that multiple calls can be chained. </returns>
-        protected virtual CosmosDbContextOptionsBuilder WithOption([NotNull] Func<CosmosDbOptionsExtension, CosmosDbOptionsExtension> setAction)
+        protected virtual CosmosDbContextOptionsBuilder WithOption([NotNull] Func<CosmosOptionsExtension, CosmosOptionsExtension> setAction)
         {
             ((IDbContextOptionsBuilderInfrastructure)OptionsBuilder).AddOrUpdateExtension(
-                setAction(OptionsBuilder.Options.FindExtension<CosmosDbOptionsExtension>() ?? new CosmosDbOptionsExtension()));
+                setAction(OptionsBuilder.Options.FindExtension<CosmosOptionsExtension>() ?? new CosmosOptionsExtension()));
 
             return this;
         }

src/EFCore.Cosmos/Infrastructure/Internal/CosmosDbOptionExtension.cs

@@ -13,7 +13,7 @@
 
 namespace Microsoft.EntityFrameworkCore.Cosmos.Infrastructure.Internal
 {
-    public class CosmosDbOptionsExtension : IDbContextOptionsExtension
+    public class CosmosOptionsExtension : IDbContextOptionsExtension
     {
         private string _serviceEndPoint;
         private string _authKeyOrResourceToken;
@@ -23,11 +23,11 @@ public class CosmosDbOptionsExtension : IDbContextOptionsExtension
         private string _logFragment;
         private long? _serviceProviderHash;
 
-        public CosmosDbOptionsExtension()
+        public CosmosOptionsExtension()
         {
         }
 
-        protected CosmosDbOptionsExtension(CosmosDbOptionsExtension copyFrom)
+        protected CosmosOptionsExtension(CosmosOptionsExtension copyFrom)
         {
             _serviceEndPoint = copyFrom._serviceEndPoint;
             _authKeyOrResourceToken = copyFrom._authKeyOrResourceToken;
@@ -38,7 +38,7 @@ protected CosmosDbOptionsExtension(CosmosDbOptionsExtension copyFrom)
 
         public virtual string ServiceEndPoint => _serviceEndPoint;
 
-        public virtual CosmosDbOptionsExtension WithServiceEndPoint(string serviceEndPoint)
+        public virtual CosmosOptionsExtension WithServiceEndPoint(string serviceEndPoint)
         {
             var clone = Clone();
 
@@ -49,7 +49,7 @@ public virtual CosmosDbOptionsExtension WithServiceEndPoint(string serviceEndPoi
 
         public virtual string AuthKeyOrResourceToken => _authKeyOrResourceToken;
 
-        public virtual CosmosDbOptionsExtension WithAuthKeyOrResourceToken(string authKeyOrResourceToken)
+        public virtual CosmosOptionsExtension WithAuthKeyOrResourceToken(string authKeyOrResourceToken)
         {
             var clone = Clone();
 
@@ -60,7 +60,7 @@ public virtual CosmosDbOptionsExtension WithAuthKeyOrResourceToken(string authKe
 
         public virtual string DatabaseName => _databaseName;
 
-        public virtual CosmosDbOptionsExtension WithDatabaseName(string database)
+        public virtual CosmosOptionsExtension WithDatabaseName(string database)
         {
             var clone = Clone();
 
@@ -71,7 +71,7 @@ public virtual CosmosDbOptionsExtension WithDatabaseName(string database)
 
         public virtual string Region => _region;
 
-        public virtual CosmosDbOptionsExtension WithRegion(string region)
+        public virtual CosmosOptionsExtension WithRegion(string region)
         {
             var clone = Clone();
 
@@ -92,7 +92,7 @@ public virtual CosmosDbOptionsExtension WithRegion(string region)
         /// </summary>
         /// <param name="executionStrategyFactory"> The option to change. </param>
         /// <returns> A new instance with the option changed. </returns>
-        public virtual CosmosDbOptionsExtension WithExecutionStrategyFactory(
+        public virtual CosmosOptionsExtension WithExecutionStrategyFactory(
             [CanBeNull] Func<ExecutionStrategyDependencies, IExecutionStrategy> executionStrategyFactory)
         {
             var clone = Clone();
@@ -102,7 +102,7 @@ public virtual CosmosDbOptionsExtension WithExecutionStrategyFactory(
             return clone;
         }
 
-        protected virtual CosmosDbOptionsExtension Clone() => new CosmosDbOptionsExtension(this);
+        protected virtual CosmosOptionsExtension Clone() => new CosmosOptionsExtension(this);
 
         public bool ApplyServices(IServiceCollection services)
         {

src/EFCore.Cosmos/Infrastructure/Internal/CosmosSingletonOptions.cs

@@ -55,7 +55,7 @@ public class CosmosSingletonOptions : ICosmosSingletonOptions
         /// </summary>
         public virtual void Initialize(IDbContextOptions options)
         {
-            var cosmosOptions = options.FindExtension<CosmosDbOptionsExtension>();
+            var cosmosOptions = options.FindExtension<CosmosOptionsExtension>();
             if (cosmosOptions != null)
             {
                 ServiceEndPoint = cosmosOptions.ServiceEndPoint;
@@ -72,7 +72,7 @@ public virtual void Initialize(IDbContextOptions options)
         /// </summary>
         public virtual void Validate(IDbContextOptions options)
         {
-            var inMemoryOptions = options.FindExtension<CosmosDbOptionsExtension>();
+            var inMemoryOptions = options.FindExtension<CosmosOptionsExtension>();
 
             if (inMemoryOptions != null
                 && (ServiceEndPoint != inMemoryOptions.ServiceEndPoint

src/EFCore.Cosmos/Storage/Internal/CosmosClientWrapper.cs

@@ -57,7 +57,7 @@ public CosmosClientWrapper(
             [NotNull] IExecutionStrategyFactory executionStrategyFactory,
             [NotNull] IDiagnosticsLogger<DbLoggerCategory.Database.Command> commandLogger)
         {
-            var options = dbContextOptions.FindExtension<CosmosDbOptionsExtension>();
+            var options = dbContextOptions.FindExtension<CosmosOptionsExtension>();
 
             _singletonWrapper = singletonWrapper;
             _databaseId = options.DatabaseName;

src/EFCore.Cosmos/Storage/Internal/CosmosExecutionStrategyFactory.cs

@@ -38,7 +38,7 @@ public CosmosExecutionStrategyFactory([NotNull] ExecutionStrategyDependencies de
 
             Dependencies = dependencies;
 
-            _createExecutionStrategy = dependencies.Options?.FindExtension<CosmosDbOptionsExtension>()?.ExecutionStrategyFactory
+            _createExecutionStrategy = dependencies.Options?.FindExtension<CosmosOptionsExtension>()?.ExecutionStrategyFactory
                                        ?? CreateDefaultStrategy;
         }
 

src/EFCore.InMemory/Extensions/InMemoryDatabaseFacadeExtensions.cs

@@ -17,7 +17,7 @@ public static class InMemoryDatabaseFacadeExtensions
     {
         /// <summary>
         ///     <para>
-        ///         Returns true if the database provider currently in use is the in-memory provider.
+        ///         Returns <c>true</c> if the database provider currently in use is the in-memory provider.
         ///     </para>
         ///     <para>
         ///         This method can only be used after the <see cref="DbContext" /> has been configured because
@@ -27,7 +27,7 @@ public static class InMemoryDatabaseFacadeExtensions
         ///     </para>
         /// </summary>
         /// <param name="database"> The facade from <see cref="DbContext.Database" />. </param>
-        /// <returns> True if the in-memory database is being used; false otherwise. </returns>
+        /// <returns> <c>true</c> if the in-memory database is being used. </returns>
         public static bool IsInMemory([NotNull] this DatabaseFacade database)
             => database.ProviderName.Equals(
                 typeof(InMemoryOptionsExtension).GetTypeInfo().Assembly.GetName().Name,

test/EFCore.Cosmos.FunctionalTests/ConfigPatternsCosmosTest.cs

@@ -30,6 +30,7 @@ public void Cosmos_client_instance_is_shared_between_contexts()
                 {
                     client = context.Database.GetCosmosClient();
                     Assert.NotNull(client);
+                    Assert.True(context.Database.IsCosmos());
                 }
 
                 using (var context = new CustomerContext(options))

test/EFCore.Cosmos.Tests/Extensions/CosmosDbContextOptionsExtensionsTests.cs

@@ -18,14 +18,11 @@ public void Can_create_options_with_specified_region()
                 o => { o.Region(regionName); });
 
             var extension = options
-                .Options.FindExtension<CosmosDbOptionsExtension>();
+                .Options.FindExtension<CosmosOptionsExtension>();
 
             Assert.Equal(regionName, extension.Region);
         }
 
-        /// <summary>
-        /// The region will be checked by the cosmosdb sdk, because the region list is not constant
-        /// </summary>
         [ConditionalFact]
         public void Can_create_options_with_wrong_region()
         {
@@ -37,8 +34,9 @@ public void Can_create_options_with_wrong_region()
                 o => { o.Region(regionName); });
 
             var extension = options
-                .Options.FindExtension<CosmosDbOptionsExtension>();
+                .Options.FindExtension<CosmosOptionsExtension>();
 
+            // The region will be validated by the Cosmos SDK, because the region list is not constant
             Assert.Equal(regionName, extension.Region);
         }
     }