Added tests for logging

src/Microsoft.AspNetCore.Cors/Infrastructure/CorsService.cs

@@ -97,26 +97,40 @@ namespace Microsoft.AspNetCore.Cors.Infrastructure
         public virtual void EvaluateRequest(HttpContext context, CorsPolicy policy, CorsResult result)
         {
             var origin = context.Request.Headers[CorsConstants.Origin];
-            if (StringValues.IsNullOrEmpty(origin) || !policy.AllowAnyOrigin && !policy.Origins.Contains(origin))
+            if (StringValues.IsNullOrEmpty(origin))
             {
                 return;
             }
 
+            if (!policy.AllowAnyOrigin && !policy.Origins.Contains(origin))
+            {
+                _logger?.RequestHasOriginHeader();
+                _logger.PolicyFailure($"Request origin {origin} does not have permission to access the resource.");
+                return;
+            }
+
             _logger?.RequestHasOriginHeader();
             AddOriginToResult(origin, policy, result);
             result.SupportsCredentials = policy.SupportsCredentials;
-            _logger?.PolicySuccess();
             AddHeaderValues(result.AllowedExposedHeaders, policy.ExposedHeaders);
+            _logger?.PolicySuccess();
         }
 
         public virtual void EvaluatePreflightRequest(HttpContext context, CorsPolicy policy, CorsResult result)
         {
             var origin = context.Request.Headers[CorsConstants.Origin];
-            if (StringValues.IsNullOrEmpty(origin) || !policy.AllowAnyOrigin && !policy.Origins.Contains(origin))
+            if (StringValues.IsNullOrEmpty(origin))
             {
                 return;
             }
 
+            if (!policy.AllowAnyOrigin && !policy.Origins.Contains(origin))
+            {
+                _logger?.RequestHasOriginHeader();
+                _logger.PolicyFailure($"Request origin {origin} does not have permission to access the resource.");
+                return;
+            }
+
             _logger?.RequestHasOriginHeader();
             var accessControlRequestMethod = context.Request.Headers[CorsConstants.AccessControlRequestMethod];
             if (StringValues.IsNullOrEmpty(accessControlRequestMethod))
@@ -160,8 +174,8 @@ namespace Microsoft.AspNetCore.Cors.Infrastructure
             result.SupportsCredentials = policy.SupportsCredentials;
             result.PreflightMaxAge = policy.PreflightMaxAge;
             result.AllowedMethods.Add(accessControlRequestMethod);
-            _logger?.PolicySuccess();
             AddHeaderValues(result.AllowedHeaders, requestHeaders);
+            _logger?.PolicySuccess();
         }
 
         /// <inheritdoc />

test/Microsoft.AspNetCore.Cors.Test/CorsServiceTests.cs

@@ -4,6 +4,7 @@
 using System;
 using Microsoft.AspNetCore.Http;
 using Xunit;
+using Microsoft.Extensions.Logging.Testing;
 
 namespace Microsoft.AspNetCore.Cors.Infrastructure
 {
@@ -227,6 +228,81 @@ namespace Microsoft.AspNetCore.Cors.Infrastructure
             Assert.Contains("PUT", result.AllowedMethods);
         }
 
+        public static TheoryData<string, string, string[], string> LoggingData
+        {
+            get
+            {
+                return new TheoryData<string, string, string[], string>
+                {
+                    {
+                        "http://example.com",
+                        "PUT",
+                        null,
+                        "Policy execution failed. Request origin http://example.com does not have permission to access the resource."
+                    },
+                    {
+                        "http://allowedexample.com",
+                        "DELETE",
+                        null,
+                        "Policy execution failed. Request method DELETE not allowed in CORS policy."
+                    },
+                    {
+                        "http://allowedexample.com",
+                        "PUT",
+                        new[] { "test" },
+                        "Policy execution failed. One or more request header(s) not allowed in CORS policy."
+                    },
+                    {
+                        "http://allowedexample.com",
+                        "PUT",
+                        null,
+                        "Policy execution successful."
+                    },
+                };
+            }
+        }
+
+        [Theory]
+        [MemberData(nameof(LoggingData))]
+        public void EvaluatePolicy_LoggingForPreflightRequests(string origin, string method, string[] headers, string logMessage)
+        {
+            var sink = new TestSink();
+            var loggerFactory = new TestLoggerFactory(sink, enabled: true);
+
+            var corsService = new CorsService(new TestCorsOptions(), loggerFactory);
+            var requestContext = GetHttpContext(method: "OPTIONS", origin: origin, accessControlRequestMethod: method, accessControlRequestHeaders: headers);
+            var policy = new CorsPolicy();
+            policy.Origins.Add("http://allowedexample.com");
+            policy.Methods.Add("PUT");
+
+            // Act
+            var result = corsService.EvaluatePolicy(requestContext, policy);
+
+            Assert.Equal("The request is preflight.", sink.Writes[0].State.ToString());
+            Assert.Equal("The request has an origin header.", sink.Writes[1].State.ToString());
+            Assert.Equal(logMessage, sink.Writes[2].State.ToString());
+        }
+
+        [Theory]
+        [InlineData("http://allowedexample.com", "Policy execution successful.")]
+        [InlineData("http://example.com", "Policy execution failed. Request origin http://example.com does not have permission to access the resource.")]
+        public void EvaluatePolicy_LoggingForRequests(string origin, string logMessage)
+        {
+            var sink = new TestSink();
+            var loggerFactory = new TestLoggerFactory(sink, enabled: true);
+
+            var corsService = new CorsService(new TestCorsOptions(), loggerFactory);
+            var requestContext = GetHttpContext(origin: origin);
+            var policy = new CorsPolicy();
+            policy.Origins.Add("http://allowedexample.com");
+
+            // Act
+            var result = corsService.EvaluatePolicy(requestContext, policy);
+
+            Assert.Equal("The request has an origin header.", sink.Writes[0].State.ToString());
+            Assert.Equal(logMessage, sink.Writes[1].State.ToString());
+        }
+
         [Theory]
         [InlineData("OpTions")]
         [InlineData("OPTIONS")]