13 files changed, 73 insertions, 13 deletions

diff --git a/src/test/burn/TestData/DependencyTests/PatchA/PatchA.wixproj b/src/test/burn/TestData/DependencyTests/PatchA/PatchA.wixproj
index 4809934d..bf20b708 100644
--- a/src/test/burn/TestData/DependencyTests/PatchA/PatchA.wixproj
+++ b/src/test/burn/TestData/DependencyTests/PatchA/PatchA.wixproj
@@ -1,7 +1,7 @@
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
 <Project Sdk="WixToolset.Sdk">
   <PropertyGroup>
-    <OutputType>PatchCreation</OutputType>
+    <OutputType>Patch</OutputType>
     <TargetExt>.msp</TargetExt>
     <SuppressSpecificWarnings>1079</SuppressSpecificWarnings>
   </PropertyGroup>
diff --git a/src/test/burn/TestData/DependencyTests/PatchB/PatchB.wixproj b/src/test/burn/TestData/DependencyTests/PatchB/PatchB.wixproj
index c099f008..5fbdd549 100644
--- a/src/test/burn/TestData/DependencyTests/PatchB/PatchB.wixproj
+++ b/src/test/burn/TestData/DependencyTests/PatchB/PatchB.wixproj
@@ -1,7 +1,7 @@
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
 <Project Sdk="WixToolset.Sdk">
   <PropertyGroup>
-    <OutputType>PatchCreation</OutputType>
+    <OutputType>Patch</OutputType>
     <TargetExt>.msp</TargetExt>
     <SuppressSpecificWarnings>1079</SuppressSpecificWarnings>
   </PropertyGroup>
diff --git a/src/test/burn/TestData/PatchTests/PatchA2/PatchA2.wixproj b/src/test/burn/TestData/PatchTests/PatchA2/PatchA2.wixproj
index da9acb5e..3deb2263 100644
--- a/src/test/burn/TestData/PatchTests/PatchA2/PatchA2.wixproj
+++ b/src/test/burn/TestData/PatchTests/PatchA2/PatchA2.wixproj
@@ -1,7 +1,7 @@
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
 <Project Sdk="WixToolset.Sdk">
   <PropertyGroup>
-    <OutputType>PatchCreation</OutputType>
+    <OutputType>Patch</OutputType>
     <TargetExt>.msp</TargetExt>
     <SuppressSpecificWarnings>1079</SuppressSpecificWarnings>
   </PropertyGroup>
@@ -9,4 +9,4 @@
     <ProjectReference Include="..\PackageAv1\PackageAv1.wixproj" />
     <ProjectReference Include="..\PackageAv1_0_1\PackageAv1_0_1.wixproj" />
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/test/burn/TestData/SlipstreamTests/PatchA/PatchA.wixproj b/src/test/burn/TestData/SlipstreamTests/PatchA/PatchA.wixproj
index da9acb5e..3deb2263 100644
--- a/src/test/burn/TestData/SlipstreamTests/PatchA/PatchA.wixproj
+++ b/src/test/burn/TestData/SlipstreamTests/PatchA/PatchA.wixproj
@@ -1,7 +1,7 @@
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
 <Project Sdk="WixToolset.Sdk">
   <PropertyGroup>
-    <OutputType>PatchCreation</OutputType>
+    <OutputType>Patch</OutputType>
     <TargetExt>.msp</TargetExt>
     <SuppressSpecificWarnings>1079</SuppressSpecificWarnings>
   </PropertyGroup>
@@ -9,4 +9,4 @@
     <ProjectReference Include="..\PackageAv1\PackageAv1.wixproj" />
     <ProjectReference Include="..\PackageAv1_0_1\PackageAv1_0_1.wixproj" />
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/test/burn/TestData/SlipstreamTests/PatchAB/PatchAB.wixproj b/src/test/burn/TestData/SlipstreamTests/PatchAB/PatchAB.wixproj
index 81fa9e12..5f9ee5f6 100644
--- a/src/test/burn/TestData/SlipstreamTests/PatchAB/PatchAB.wixproj
+++ b/src/test/burn/TestData/SlipstreamTests/PatchAB/PatchAB.wixproj
@@ -1,7 +1,7 @@
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
 <Project Sdk="WixToolset.Sdk">
   <PropertyGroup>
-    <OutputType>PatchCreation</OutputType>
+    <OutputType>Patch</OutputType>
     <TargetExt>.msp</TargetExt>
     <SuppressSpecificWarnings>1079</SuppressSpecificWarnings>
   </PropertyGroup>
@@ -11,4 +11,4 @@
     <ProjectReference Include="..\PackageBv1\PackageBv1.wixproj" />
     <ProjectReference Include="..\PackageBv1_0_1\PackageBv1_0_1.wixproj" />
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/test/burn/TestData/SlipstreamTests/PatchAB2/PatchAB2.wixproj b/src/test/burn/TestData/SlipstreamTests/PatchAB2/PatchAB2.wixproj
index 81fa9e12..5f9ee5f6 100644
--- a/src/test/burn/TestData/SlipstreamTests/PatchAB2/PatchAB2.wixproj
+++ b/src/test/burn/TestData/SlipstreamTests/PatchAB2/PatchAB2.wixproj
@@ -1,7 +1,7 @@
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
 <Project Sdk="WixToolset.Sdk">
   <PropertyGroup>
-    <OutputType>PatchCreation</OutputType>
+    <OutputType>Patch</OutputType>
     <TargetExt>.msp</TargetExt>
     <SuppressSpecificWarnings>1079</SuppressSpecificWarnings>
   </PropertyGroup>
@@ -11,4 +11,4 @@
     <ProjectReference Include="..\PackageBv1\PackageBv1.wixproj" />
     <ProjectReference Include="..\PackageBv1_0_1\PackageBv1_0_1.wixproj" />
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/wix/WixToolset.Core.Burn/BurnBackendFactory.cs b/src/wix/WixToolset.Core.Burn/BurnBackendFactory.cs
index 03013a08..63f52200 100644
--- a/src/wix/WixToolset.Core.Burn/BurnBackendFactory.cs
+++ b/src/wix/WixToolset.Core.Burn/BurnBackendFactory.cs
@@ -18,6 +18,7 @@ namespace WixToolset.Core.Burn
             switch (outputType.ToLowerInvariant())
             {
                 case "bundle":
+                case "burn":
                 case ".exe":
                     backend = new BundleBackend();
                     return true;
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/WindowsInstallerBackendFactory.cs b/src/wix/WixToolset.Core.WindowsInstaller/WindowsInstallerBackendFactory.cs
index d14743e9..42e1a45d 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/WindowsInstallerBackendFactory.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/WindowsInstallerBackendFactory.cs
@@ -18,6 +18,7 @@ namespace WixToolset.Core.WindowsInstaller
             switch (outputType?.ToLowerInvariant())
             {
                 case "module":
+                case "msm":
                 case ".msm":
                     backend = new MsmBackend();
                     return true;
@@ -25,11 +26,14 @@ namespace WixToolset.Core.WindowsInstaller
                 case "msipackage":
                 case "package":
                 case "product":
+                case "msi":
                 case ".msi":
                     backend = new MsiBackend();
                     return true;
 
+                case "msppackage":
                 case "patch":
+                case "msp":
                 case ".msp":
                     backend = new MspBackend();
                     return true;
diff --git a/src/wix/WixToolset.Core/BindContext.cs b/src/wix/WixToolset.Core/BindContext.cs
index 1c1f7528..50ccdec6 100644
--- a/src/wix/WixToolset.Core/BindContext.cs
+++ b/src/wix/WixToolset.Core/BindContext.cs
@@ -42,6 +42,8 @@ namespace WixToolset.Core
 
         public string OutputPath { get; set; }
 
+        public string OutputType { get; set; }
+
         public PdbType PdbType { get; set; }
 
         public string PdbPath { get; set; }
diff --git a/src/wix/WixToolset.Core/Binder.cs b/src/wix/WixToolset.Core/Binder.cs
index 204ab6ee..fd6e1470 100644
--- a/src/wix/WixToolset.Core/Binder.cs
+++ b/src/wix/WixToolset.Core/Binder.cs
@@ -58,18 +58,27 @@ namespace WixToolset.Core
 
             var backendFactories = extensionManager.GetServices<IBackendFactory>();
 
-            var entrySection = context.IntermediateRepresentation.Sections.First();
+            var outputType = context is BindContext bindContext ? bindContext.OutputType : null;
+
+            if (String.IsNullOrEmpty(outputType))
+            {
+                var entrySection = context.IntermediateRepresentation.Sections.First();
+
+                outputType = entrySection.Type.ToString();
+            }
 
             foreach (var factory in backendFactories)
             {
-                if (factory.TryCreateBackend(entrySection.Type.ToString(), context.OutputPath, out var backend))
+                if (factory.TryCreateBackend(outputType, context.OutputPath, out var backend))
                 {
                     var result = backend.Bind(context);
                     return result;
                 }
             }
 
-            // TODO: messaging that a backend could not be found to bind the output type?
+            var messaging = context.ServiceProvider.GetService<IMessaging>();
+
+            messaging.Write(CoreErrors.BackendNotFound(outputType, context.OutputPath));
 
             return null;
         }
diff --git a/src/wix/WixToolset.Core/CommandLine/BuildCommand.cs b/src/wix/WixToolset.Core/CommandLine/BuildCommand.cs
index 965280d0..9ed68d81 100644
--- a/src/wix/WixToolset.Core/CommandLine/BuildCommand.cs
+++ b/src/wix/WixToolset.Core/CommandLine/BuildCommand.cs
@@ -316,6 +316,11 @@ namespace WixToolset.Core.CommandLine
                     context.PdbPath = inputsOutputs.PdbPath;
                     context.CancellationToken = cancellationToken;
 
+                    if (context is BindContext bindContext)
+                    {
+                        bindContext.OutputType = this.commandLine.OutputType;
+                    }
+
                     var binder = this.ServiceProvider.GetService<IBinder>();
                     bindResult = binder.Bind(context);
                 }
diff --git a/src/wix/WixToolset.Core/CoreErrors.cs b/src/wix/WixToolset.Core/CoreErrors.cs
index 6dbd6c88..16feb9dc 100644
--- a/src/wix/WixToolset.Core/CoreErrors.cs
+++ b/src/wix/WixToolset.Core/CoreErrors.cs
@@ -26,6 +26,11 @@ namespace WixToolset.Core
             return Message(sourceLineNumbers, Ids.UnableToOpenFile, "Unable to open file: {0}. Error detail: {1}", path, detail);
         }
 
+        public static Message BackendNotFound(string outputType, string outputPath)
+        {
+            return Message(null, Ids.BackendNotFound, "Unable to find a backend to process output type: {0} for output file: {1}. Specify a different output type or output file extension.", outputType, outputPath);
+        }
+
         private static Message Message(SourceLineNumber sourceLineNumber, Ids id, string format, params object[] args)
         {
             return new Message(sourceLineNumber, MessageLevel.Error, (int)id, format, args);
@@ -37,6 +42,7 @@ namespace WixToolset.Core
             UnableToDeleteFile = 7011,
             UnableToMoveFile = 7012,
             UnableToOpenFile = 7013,
+            BackendNotFound = 7014,
         } // last available is 7099. 7100 is WindowsInstallerBackendWarnings.
     }
 }
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/BadInputFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/BadInputFixture.cs
index f571d13b..ce28faff 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/BadInputFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/BadInputFixture.cs
@@ -222,6 +222,39 @@ namespace WixToolsetTest.CoreIntegration
         }
 
         [Fact]
+        public void CannotBuildWithUnknownOutputType()
+        {
+            var folder = TestData.Get(@"TestData");
+
+            using (var fs = new DisposableFileSystem())
+            {
+                var baseFolder = fs.GetFolder();
+                var intermediateFolder = Path.Combine(baseFolder, "obj");
+                var outputPath = Path.Combine(intermediateFolder, @"test.pkg");
+
+                var result = WixRunner.Execute(new[]
+                {
+                    "build",
+                    Path.Combine(folder, "SimplePackage", "SimplePackage.wxs"),
+                    "-intermediateFolder", intermediateFolder,
+                    "-bindpath", Path.Combine(folder, ".Data"),
+                    "-outputType", "invalid",
+                    "-o", outputPath,
+                });
+
+                var messages = result.Messages.Select(m => m.ToString()).ToList();
+                messages.Sort();
+
+                WixAssert.CompareLineByLine(new[]
+                {
+                    @"Unable to find a backend to process output type: invalid for output file: <folder>\test.pkg. Specify a different output type or output file extension.",
+                }, messages.Select(s => s.Replace(intermediateFolder, "<folder>")).ToArray());
+
+                Assert.Equal(7014, result.ExitCode);
+            }
+        }
+
+        [Fact]
         public void GuardsAgainstVariousBundleValuesFromLoc()
         {
             var folder = TestData.Get(@"TestData");