Allow build --no-restore for file-based programs (#49013)

Author: marcpopMSFT

src/Cli/dotnet/Commands/Run/RunCommand.cs

@@ -110,14 +110,14 @@ public int Execute()
         }
         else
         {
-            if (EntryPointFileFullPath is not null)
+            if (NoCache)
             {
-                projectFactory = CreateVirtualCommand().PrepareProjectInstance().CreateProjectInstance;
+                throw new GracefulException(CliCommandStrings.InvalidOptionCombination, RunCommandParser.NoCacheOption.Name, RunCommandParser.NoBuildOption.Name);
             }
 
-            if (NoCache)
+            if (EntryPointFileFullPath is not null)
             {
-                throw new GracefulException(CliCommandStrings.InvalidOptionCombination, RunCommandParser.NoCacheOption.Name, RunCommandParser.NoBuildOption.Name);
+                projectFactory = CreateVirtualCommand().PrepareProjectInstance().CreateProjectInstance;
             }
         }
 

src/Cli/dotnet/Commands/Run/VirtualProjectBuildingCommand.cs

@@ -97,11 +97,6 @@ public override int Execute()
         {
             if (NoCache)
             {
-                if (NoRestore)
-                {
-                    throw new GracefulException(CliCommandStrings.InvalidOptionCombination, RunCommandParser.NoCacheOption.Name, RunCommandParser.NoRestoreOption.Name);
-                }
-
                 cacheEntry = ComputeCacheEntry(out _);
             }
             else if (!NeedsToBuild(out cacheEntry))

test/dotnet.Tests/CommandTests/Run/RunFileTests.cs

@@ -719,7 +719,7 @@ Resource not found
     }
 
     [Fact]
-    public void NoRestore()
+    public void NoRestore_01()
     {
         var testInstance = _testAssetsManager.CreateTestDirectory();
         var programFile = Path.Join(testInstance.Path, "Program.cs");
@@ -750,6 +750,43 @@ public void NoRestore()
             .And.HaveStdOut("Hello from Program");
     }
 
+    [Fact]
+    public void NoRestore_02()
+    {
+        var testInstance = _testAssetsManager.CreateTestDirectory();
+        var programFile = Path.Join(testInstance.Path, "Program.cs");
+        File.WriteAllText(programFile, s_program);
+
+        // Remove artifacts from possible previous runs of this test.
+        var artifactsDir = VirtualProjectBuildingCommand.GetArtifactsPath(programFile);
+        if (Directory.Exists(artifactsDir)) Directory.Delete(artifactsDir, recursive: true);
+
+        // It is an error when never restored before.
+        new DotnetCommand(Log, "build", "--no-restore", "Program.cs")
+            .WithWorkingDirectory(testInstance.Path)
+            .Execute()
+            .Should().Fail()
+            .And.HaveStdOutContaining("NETSDK1004"); // error NETSDK1004: Assets file '...\obj\project.assets.json' not found. Run a NuGet package restore to generate this file.
+
+        // Run restore.
+        new DotnetCommand(Log, "restore", "Program.cs")
+            .WithWorkingDirectory(testInstance.Path)
+            .Execute()
+            .Should().Pass();
+
+        // --no-restore works.
+        new DotnetCommand(Log, "build", "--no-restore", "Program.cs")
+            .WithWorkingDirectory(testInstance.Path)
+            .Execute()
+            .Should().Pass();
+
+        new DotnetCommand(Log, "run", "--no-build", "Program.cs")
+            .WithWorkingDirectory(testInstance.Path)
+            .Execute()
+            .Should().Pass()
+            .And.HaveStdOut("Hello from Program");
+    }
+
     [Fact]
     public void NoBuild_01()
     {
@@ -1168,12 +1205,6 @@ public void UpToDate_InvalidOptions()
             .Execute()
             .Should().Fail()
             .And.HaveStdErrContaining(string.Format(CliCommandStrings.InvalidOptionCombination, RunCommandParser.NoCacheOption.Name, RunCommandParser.NoBuildOption.Name));
-
-        new DotnetCommand(Log, "run", "Program.cs", "--no-cache", "--no-restore")
-            .WithWorkingDirectory(testInstance.Path)
-            .Execute()
-            .Should().Fail()
-            .And.HaveStdErrContaining(string.Format(CliCommandStrings.InvalidOptionCombination, RunCommandParser.NoCacheOption.Name, RunCommandParser.NoRestoreOption.Name));
     }
 
     private static string ToJson(string s) => JsonSerializer.Serialize(s);