Added unit tests for MicrosoftExtensionsConnectionStringProvider.

Author: ckadluba

test/Serilog.Sinks.MSSqlServer.Tests/Configuration/Implementations/Microsoft.Extensions.Configuration/MicrosoftExtensionsConnectionStringProviderTests.cs

@@ -0,0 +1,46 @@
+using Microsoft.Extensions.Configuration;
+using Moq;
+using Serilog.Sinks.MSSqlServer.Configuration;
+using Xunit;
+
+namespace Serilog.Sinks.MSSqlServer.Tests.Configuration.Implementations.Microsoft.Extensions.Configuration
+{
+    public class MicrosoftExtensionsConnectionStringProviderTests
+    {
+        [Fact]
+        public void GetConnectionStringCalledWithConnectionStringReturnsSameValue()
+        {
+            // Arrange
+            const string connectionString = "Server=localhost;Database=LogTest;Integrated Security=SSPI;";
+            var configurationMock = new Mock<IConfiguration>();
+            var sut = new MicrosoftExtensionsConnectionStringProvider();
+
+            // Act
+            var result = sut.GetConnectionString(connectionString, configurationMock.Object);
+
+            // Assert
+            Assert.Equal(connectionString, result);
+        }
+
+        [Fact]
+        public void GetConnectionStringCalledWithNameItGetsConnectionStringFromConfig()
+        {
+            // Arrange
+            const string connectionStringName = "LogDatabase";
+            const string connectionString = "Server=localhost;Database=LogTest;Integrated Security=SSPI;";
+            var configurationMock = new Mock<IConfiguration>();
+            var configSectionMock = new Mock<IConfigurationSection>();
+            configurationMock.Setup(c => c.GetSection(It.IsAny<string>())).Returns(configSectionMock.Object);
+            configSectionMock.Setup(c => c[It.IsAny<string>()]).Returns(connectionString);
+            var sut = new MicrosoftExtensionsConnectionStringProvider();
+
+            // Act
+            var result = sut.GetConnectionString(connectionStringName, configurationMock.Object);
+
+            // Assert
+            configurationMock.Verify(c => c.GetSection("ConnectionStrings"), Times.Once);
+            configSectionMock.Verify(c => c[connectionStringName], Times.Once);
+            Assert.Equal(connectionString, result);
+        }
+    }
+}