Publish can skip Build

src/dotnet/commands/dotnet-publish/Program.cs

@@ -28,6 +28,7 @@ namespace Microsoft.DotNet.Tools.Publish
             var configuration = app.Option("-c|--configuration <CONFIGURATION>", "Configuration under which to build", CommandOptionType.SingleValue);
             var projectPath = app.Argument("<PROJECT>", "The project to publish, defaults to the current directory. Can be a path to a project.json or a project directory");
             var nativeSubdirectories = app.Option("--native-subdirectory", "Temporary mechanism to include subdirectories from native assets of dependency packages in output", CommandOptionType.NoValue);
+            var noBuild = app.Option("--no-build", "Do not build projects before publishing", CommandOptionType.NoValue);
 
             app.OnExecute(() =>
             {
@@ -41,6 +42,7 @@ namespace Microsoft.DotNet.Tools.Publish
                 publish.NativeSubdirectories = nativeSubdirectories.HasValue();
                 publish.ProjectPath = projectPath.Value;
                 publish.VersionSuffix = versionSuffix.Value();
+                publish.ShouldBuild = !noBuild.HasValue();
 
                 if (string.IsNullOrEmpty(publish.ProjectPath))
                 {

src/dotnet/commands/dotnet-publish/PublishCommand.cs

@@ -35,6 +35,7 @@ namespace Microsoft.DotNet.Tools.Publish
         public string VersionSuffix { get; set; }
         public int NumberOfProjects { get; private set; }
         public int NumberOfPublishedProjects { get; private set; }
+        public bool ShouldBuild { get; set; }
 
         public bool TryPrepareForPublish()
         {
@@ -119,34 +120,7 @@ namespace Microsoft.DotNet.Tools.Publish
             }
 
             // Compile the project (and transitively, all it's dependencies)
-            var args = new List<string>() {
+            if (ShouldBuild && !InvokeBuildOnProject(context, buildBasePath, configuration))
-                "--framework",
-                $"{context.TargetFramework.DotNetFrameworkName}",
-                "--configuration",
-                configuration,
-                context.ProjectFile.ProjectDirectory
-            };
-
-            if (!string.IsNullOrEmpty(context.RuntimeIdentifier))
-            {
-                args.Insert(0, context.RuntimeIdentifier);
-                args.Insert(0, "--runtime");
-            }
-
-            if (!string.IsNullOrEmpty(VersionSuffix))
-            {
-                args.Add("--version-suffix");
-                args.Add(VersionSuffix);
-            }
-
-            if (!string.IsNullOrEmpty(buildBasePath))
-            {
-                args.Add("--build-base-path");
-                args.Add(buildBasePath);
-            }
-
-            var result = Build.BuildCommand.Run(args.ToArray());
-            if (result != 0)
             {
                 return false;
             }
@@ -206,6 +180,40 @@ namespace Microsoft.DotNet.Tools.Publish
             return true;
         }
 
+        private Boolean InvokeBuildOnProject(ProjectContext context, String buildBasePath, String configuration)
+        {
+            var args = new List<string>()
+            {
+                "--framework",
+                $"{context.TargetFramework.DotNetFrameworkName}",
+                "--configuration",
+                configuration,
+                context.ProjectFile.ProjectDirectory
+            };
+
+            if (!string.IsNullOrEmpty(context.RuntimeIdentifier))
+            {
+                args.Insert(0, context.RuntimeIdentifier);
+                args.Insert(0, "--runtime");
+            }
+
+            if (!string.IsNullOrEmpty(VersionSuffix))
+            {
+                args.Add("--version-suffix");
+                args.Add(VersionSuffix);
+            }
+
+            if (!string.IsNullOrEmpty(buildBasePath))
+            {
+                args.Add("--build-base-path");
+                args.Add(buildBasePath);
+            }
+
+            var result = Build.BuildCommand.Run(args.ToArray());
+
+            return result == 0;
+        }
+
         private HashSet<string> GetExclusionList(ProjectContext context, Dictionary<string, LibraryExport> exports)
         {
             var exclusionList = new HashSet<string>();

test/Microsoft.DotNet.Tools.Tests.Utilities/Commands/PublishCommand.cs

@@ -19,9 +19,10 @@ namespace Microsoft.DotNet.Tools.Test.Utilities
         private readonly string _framework;
         private readonly string _runtime;
         private readonly string _config;
+        private readonly bool _noBuild;
         private readonly string _output;
 
-        public PublishCommand(string projectPath, string framework = "", string runtime = "", string output = "", string config = "", bool forcePortable = false)
+        public PublishCommand(string projectPath, string framework = "", string runtime = "", string output = "", string config = "", bool forcePortable = false, bool noBuild = false)
             : base("dotnet")
         {
             _path = projectPath;
@@ -30,6 +31,7 @@ namespace Microsoft.DotNet.Tools.Test.Utilities
             _runtime = runtime;
             _output = output;
             _config = config;
+            _noBuild = noBuild;
         }
 
         public override CommandResult Execute(string args = "")
@@ -91,12 +93,13 @@ namespace Microsoft.DotNet.Tools.Test.Utilities
 
         private string BuildArgs()
         {
-            return $"{_path} {FrameworkOption} {RuntimeOption} {OutputOption} {ConfigOption}";
+            return $"{_path} {FrameworkOption} {RuntimeOption} {OutputOption} {ConfigOption} {NoBuildFlag}";
         }
 
         private string FrameworkOption => string.IsNullOrEmpty(_framework) ? "" : $"-f {_framework}";
         private string RuntimeOption => string.IsNullOrEmpty(_runtime) ? "" : $"-r {_runtime}";
         private string OutputOption => string.IsNullOrEmpty(_output) ? "" : $"-o \"{_output}\"";
         private string ConfigOption => string.IsNullOrEmpty(_config) ? "" : $"-c {_output}";
+        private string NoBuildFlag => _noBuild ? "--no-build" :"";
     }
 }

test/dotnet-publish.Tests/PublishTests.cs

@@ -176,6 +176,31 @@ namespace Microsoft.DotNet.Tools.Publish.Tests
             publishCommand.Execute().Should().Fail();
         }
 
+        [Fact]
+        public void PublishFailsWhenProjectNotBuiltAndNoBuildFlagSet()
+        {
+            TestInstance instance = TestAssetsManager.CreateTestInstance("TestAppCompilationContext")
+                                                     .WithLockFiles();
+
+            var testProject = _getProjectJson(instance.TestRoot, "TestApp");
+            var publishCommand = new PublishCommand(testProject, noBuild: true);
+
+            publishCommand.Execute().Should().Fail();
+        }
+
+        [Fact]
+        public void PublishSucceedsWhenProjectPreviouslyCompiledAndNoBuildFlagSet()
+        {
+            TestInstance instance = TestAssetsManager.CreateTestInstance("TestAppCompilationContext")
+                                                     .WithLockFiles()
+                                                     .WithBuildArtifacts();
+
+            var testProject = _getProjectJson(instance.TestRoot, "TestApp");
+            var publishCommand = new PublishCommand(testProject, noBuild: true);
+
+            publishCommand.Execute().Should().Pass();
+        }
+
         [Fact]
         public void PublishScriptsRun()
         {