nits

Author: jkotalik

src/Servers/IIS/IIS/samples/NativeIISSample/Startup.cs

@@ -117,15 +117,14 @@ public void Configure(IApplicationBuilder app)
 
         public static void Main(string[] args)
         {
-            throw new Exception();
-            //var host = new WebHostBuilder()
-            //    .UseKestrel()
-            //    .UseIIS()
-            //    .UseIISIntegration()
-            //    .UseStartup<Startup>()
-            //    .Build();
-
-            //host.Run();
+            var host = new WebHostBuilder()
+                .UseKestrel()
+                .UseIIS()
+                .UseIISIntegration()
+                .UseStartup<Startup>()
+                .Build();
+
+            host.Run();
         }
     }
 }

src/Servers/IIS/IIS/src/StartupHook.cs

@@ -18,6 +18,12 @@
 using Microsoft.Extensions.FileProviders;
 using Microsoft.Extensions.StackTrace.Sources;
 
+
+/// <summary>
+/// Startup hooks are pieces of code that will run before a users program main executes
+/// See: https://github.com/dotnet/core-setup/blob/master/Documentation/design-docs/host-startup-hook.md
+/// The type must be named StartupHook without any namespace, and should be internal.
+/// </summary>
 internal class StartupHook
 {
     /// <summary>
@@ -33,10 +39,21 @@ public static void Initialize()
             return;
         }
 
-        if (Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT").Equals("Development", StringComparison.OrdinalIgnoreCase) ||
-            Environment.GetEnvironmentVariable("DOTNET_ENVIRONMENT").Equals("Development", StringComparison.OrdinalIgnoreCase))
+        var detailedErrors = Environment.GetEnvironmentVariable("ASPNETCORE_DETAILEDERRORS");
+        var detailedErrorsEnabled = string.IsNullOrEmpty(detailedErrors) ?
+            false :
+            detailedErrors.Equals("1", StringComparison.OrdinalIgnoreCase) ||
+                detailedErrors.Equals("true", StringComparison.OrdinalIgnoreCase);
+
+        var aspnetCoreEnvironment = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT");
+        var aspnetCoreEnvironmentDevelopment = string.IsNullOrEmpty(aspnetCoreEnvironment) ? false : aspnetCoreEnvironment.Equals("Development", StringComparison.OrdinalIgnoreCase);
+
+        var dotnetEnvironment = Environment.GetEnvironmentVariable("DOTNET_ENVIRONMENT");
+        var dotnetEnvironmentDevelopment = string.IsNullOrEmpty(dotnetEnvironment) ? false : dotnetEnvironment.Equals("Development", StringComparison.OrdinalIgnoreCase);
+
+        if (!detailedErrorsEnabled && !aspnetCoreEnvironmentDevelopment && !dotnetEnvironmentDevelopment)
         {
-            // Not running in development.
+            // Not running in development or detailed errors aren't enabled
             return;
         }
 

src/Servers/IIS/IIS/test/Common.FunctionalTests/Inprocess/StartupTests.cs

@@ -575,14 +575,18 @@ public async Task StartupIsSuspendedWhenEventIsUsed()
             await request;
         }
 
-        [ConditionalFact]
+        [ConditionalTheory]
         [RequiresIIS(IISCapability.PoolEnvironmentVariables)]
         [RequiresNewHandler]
-        public async Task ExceptionIsLoggedToEventLogAndPutInResponseWhenDeveloperExceptionPageIsEnabled()
+        [InlineData("ASPNETCORE_ENVIRONMENT", "Development")]
+        [InlineData("DOTNET_ENVIRONMENT", "deVelopment")]
+        [InlineData("ASPNETCORE_DETAILED_ERRORS", "1")]
+        [InlineData("ASPNETCORE_DETAILED_ERRORS", "TRUE")]
+        public async Task ExceptionIsLoggedToEventLogAndPutInResponseWhenDeveloperExceptionPageIsEnabled(string environmentVariable, string value)
         {
             var deploymentParameters = Fixture.GetBaseDeploymentParameters();
             deploymentParameters.TransformArguments((a, _) => $"{a} Throw");
-            deploymentParameters.EnvironmentVariables["ASPNETCORE_ENVIRONMENT"] = "Development";
+            deploymentParameters.EnvironmentVariables[environmentVariable] = value;
             var deploymentResult = await DeployAsync(deploymentParameters);
             var result = await deploymentResult.HttpClient.GetAsync("/");
             Assert.False(result.IsSuccessStatusCode);