Fix CS2002 warning when EnableDefaultCompileItems=true in file-based …

…apps

Add condition to only include explicit Compile item when EnableDefaultCompileItems is not true. This prevents the main file from being included twice (once explicitly and once via default globbing).

Updated existing test to verify no CS2002 warning is emitted.
Added new test for Directory.Build.props scenario.

Co-authored-by: jjonescz <[email protected]>

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

@@ -1414,7 +1414,7 @@ public static void WriteProjectFile(
 
             writer.WriteLine($"""
                   <ItemGroup>
-                    <Compile Include="{EscapeValue(targetFilePath)}" />
+                    <Compile Condition="'$(EnableDefaultCompileItems)'!='true'" Include="{EscapeValue(targetFilePath)}" />
                   </ItemGroup>
 
                 """);

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

@@ -750,8 +750,32 @@ public void MultipleFiles_RunEntryPoint()
             .WithWorkingDirectory(testInstance.Path)
             .Execute()
             .Should().Pass()
-            // warning CS2002: Source file 'Program.cs' specified multiple times
-            .And.HaveStdOutContaining("warning CS2002")
+            .And.NotHaveStdOutContaining("warning CS2002")
+            .And.HaveStdOutContaining("Hello, String from Util");
+    }
+
+    /// <summary>
+    /// Setting EnableDefaultCompileItems=true via Directory.Build.props should not cause CS2002 warning.
+    /// </summary>
+    [Fact]
+    public void MultipleFiles_EnableDefaultCompileItemsViaDirectoryBuildProps()
+    {
+        var testInstance = _testAssetsManager.CreateTestDirectory();
+        File.WriteAllText(Path.Join(testInstance.Path, "Program.cs"), s_programDependingOnUtil);
+        File.WriteAllText(Path.Join(testInstance.Path, "Util.cs"), s_util);
+        File.WriteAllText(Path.Join(testInstance.Path, "Directory.Build.props"), """
+            <Project>
+                <PropertyGroup>
+                    <EnableDefaultCompileItems>true</EnableDefaultCompileItems>
+                </PropertyGroup>
+            </Project>
+            """);
+
+        new DotnetCommand(Log, "run", "Program.cs")
+            .WithWorkingDirectory(testInstance.Path)
+            .Execute()
+            .Should().Pass()
+            .And.NotHaveStdOutContaining("warning CS2002")
             .And.HaveStdOutContaining("Hello, String from Util");
     }