Handle --minimum-expected-tests (#50527)

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

Author: Youssef1313

src/Cli/dotnet/Commands/CliCommandStrings.resx

@@ -2645,4 +2645,7 @@ Proceed?</value>
   <data name="PackCmdVersion" xml:space="preserve">
     <value>VERSION</value>
   </data>
+  <data name="CmdMinimumExpectedTestsDescription" xml:space="preserve">
+    <value>Specifies the minimum number of tests that are expected to run.</value>
+  </data>
 </root>

src/Cli/dotnet/Commands/Test/ExitCode.cs

@@ -14,4 +14,5 @@ internal static class ExitCode
     public const int Success = 0;
     public const int GenericFailure = 1;
     public const int ZeroTests = 8;
+    public const int MinimumExpectedTestsPolicyViolation = 9;
 }

src/Cli/dotnet/Commands/Test/Terminal/TerminalTestReporter.cs

@@ -62,6 +62,7 @@ internal event EventHandler OnProgressStopUpdate
     private bool? _shouldShowPassedTests;
 
     public bool HasHandshakeFailure => _handshakeFailuresCount > 0;
+    public int TotalTests => _assemblies.Values.Sum(a => a.TotalTests);
 
     // Specifying no timeout, the regex is linear. And the timeout does not measure the regex only, but measures also any
     // thread suspends, so the regex gets blamed incorrectly.

src/Cli/dotnet/Commands/Test/TestCommandParser.cs

@@ -237,6 +237,7 @@ private static Command GetTestingPlatformCliCommand()
         command.Options.Add(TestingPlatformOptions.ConfigFileOption);
         command.Options.Add(TestingPlatformOptions.DiagnosticOutputDirectoryOption);
         command.Options.Add(TestingPlatformOptions.MaxParallelTestModulesOption);
+        command.Options.Add(TestingPlatformOptions.MinimumExpectedTestsOption);
         command.Options.Add(CommonOptions.ArchitectureOption);
         command.Options.Add(CommonOptions.PropertiesOption);
         command.Options.Add(TestingPlatformOptions.ConfigurationOption);

src/Cli/dotnet/Commands/Test/TestingPlatformCommand.cs

@@ -80,9 +80,18 @@ private int RunInternal(ParseResult parseResult)
         }
 
         _actionQueue.EnqueueCompleted();
-        var exitCode = _actionQueue.WaitAllActions();
         // Don't inline exitCode variable. We want to always call WaitAllActions first.
-        return _eventHandlers.HasHandshakeFailure ? ExitCode.GenericFailure : exitCode;
+        var exitCode = _actionQueue.WaitAllActions();
+        exitCode = _eventHandlers.HasHandshakeFailure ? ExitCode.GenericFailure : exitCode;
+        if (exitCode == ExitCode.Success &&
+            parseResult.HasOption(TestingPlatformOptions.MinimumExpectedTestsOption) &&
+            parseResult.GetValue(TestingPlatformOptions.MinimumExpectedTestsOption) is { } minimumExpectedTests &&
+            _output.TotalTests < minimumExpectedTests)
+        {
+            exitCode = ExitCode.MinimumExpectedTestsPolicyViolation;
+        }
+
+        return exitCode;
     }
 
     private void PrepareEnvironment(ParseResult parseResult, out TestOptions testOptions, out int degreeOfParallelism)
@@ -142,6 +151,7 @@ private void InitializeOutput(int degreeOfParallelism, ParseResult parseResult,
             UseCIAnsi = inCI,
             ShowAssembly = true,
             ShowAssemblyStartAndComplete = true,
+            MinimumExpectedTests = parseResult.GetValue(TestingPlatformOptions.MinimumExpectedTestsOption),
         });
 
         _output.TestExecutionStarted(DateTimeOffset.Now, degreeOfParallelism, _isDiscovery, isHelp, _isRetry);

src/Cli/dotnet/Commands/Test/TestingPlatformOptions.cs

@@ -62,6 +62,12 @@ internal static class TestingPlatformOptions
         HelpName = CliCommandStrings.CmdNumberName
     };
 
+    public static readonly Option<int> MinimumExpectedTestsOption = new("--minimum-expected-tests")
+    {
+        Description = CliCommandStrings.CmdMinimumExpectedTestsDescription,
+        HelpName = CliCommandStrings.CmdNumberName
+    };
+
     public static readonly Option<string> ConfigurationOption = CommonOptions.ConfigurationOption(CliCommandStrings.TestConfigurationOptionDescription);
 
     public static readonly Option<string> FrameworkOption = CommonOptions.FrameworkOption(CliCommandStrings.TestFrameworkOptionDescription);