Fail early if there are no dotnet analyzers on the server (#1811)

Tests/SonarScanner.MSBuild.PreProcessor.Test/PreProcessorTests.cs

@@ -286,30 +286,18 @@ public async Task Execute_EndToEnd_SuccessCase_With_Organization()
         }
 
         [TestMethod]
-        public async Task Execute_NoPlugin_ReturnsTrue()
+        public async Task Execute_NoPlugin_ReturnsFalseAndLogsError()
         {
             using var scope = new TestScope(TestContext);
             var factory = new MockObjectFactory();
             factory.Server.Data.Languages.Clear();
             factory.Server.Data.Languages.Add("invalid_plugin");
-            var settings = factory.ReadSettings();
             var preProcessor = new PreProcessor(factory, factory.Logger);
 
             var success = await preProcessor.Execute(CreateArgs());
-            success.Should().BeTrue("Expecting the pre-processing to complete successfully");
-
-            AssertDirectoriesCreated(settings);
-
-            factory.TargetsInstaller.Verify(x => x.InstallLoaderTargets(scope.WorkingDir), Times.Once());
-            factory.Server.AssertMethodCalled(nameof(ISonarWebServer.DownloadProperties), 1);
-            factory.Server.AssertMethodCalled(nameof(ISonarWebServer.DownloadAllLanguages), 1);
-            factory.Server.AssertMethodCalled(nameof(ISonarWebServer.DownloadQualityProfile), 0);   // No valid plugin
-            factory.Server.AssertMethodCalled(nameof(ISonarWebServer.DownloadRules), 0);               // No valid plugin
-
-            AssertAnalysisConfig(settings.AnalysisConfigFilePath, 0, factory.Logger);
+            success.Should().BeFalse("Expecting the pre-processing to fail");
 
-            // only contains SonarQubeAnalysisConfig (no rulesets or additional files)
-            AssertDirectoryContains(settings.SonarConfigDirectory, Path.GetFileName(settings.AnalysisConfigFilePath));
+            factory.Logger.AssertErrorLogged("Could not find any dotnet analyzer plugin on the server (SonarQube/SonarCloud)!");
         }
 
         [TestMethod]

src/SonarScanner.MSBuild.PreProcessor/PreProcessor.cs

@@ -137,8 +137,15 @@ private async Task<ArgumentsAndRuleSets> FetchArgumentsAndRuleSets(ISonarWebServ
                 args.TryGetSetting(SonarProperties.ProjectBranch, out var projectBranch);
                 argumentsAndRuleSets.ServerSettings = await server.DownloadProperties(args.ProjectKey, projectBranch);
                 var availableLanguages = await server.DownloadAllLanguages();
+                var knownLanguages = Languages.Where(availableLanguages.Contains).ToList();
+                if (knownLanguages.Count == 0)
+                {
+                    logger.LogError(Resources.ERR_DotNetAnalyzersNotFound);
+                    argumentsAndRuleSets.IsSuccess = false;
+                    return argumentsAndRuleSets;
+                }
 
-                foreach (var language in Languages.Where(availableLanguages.Contains))
+                foreach (var language in knownLanguages)
                 {
                     var qualityProfile = await server.DownloadQualityProfile(args.ProjectKey, projectBranch, language);
                     if (qualityProfile is not { })

src/SonarScanner.MSBuild.PreProcessor/Resources.resx

@@ -2,16 +2,16 @@
 <root>
   <!-- 
     Microsoft ResX Schema 
-    
+
     Version 2.0
-    
+
     The primary goals of this format is to allow a simple XML format 
     that is mostly human readable. The generation and parsing of the 
     various data types are done through the TypeConverter classes 
     associated with the data types.
-    
+
     Example:
-    
+
     ... ado.net/XML headers & schema ...
     <resheader name="resmimetype">text/microsoft-resx</resheader>
     <resheader name="version">2.0</resheader>
@@ -26,29 +26,29 @@
         <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
         <comment>This is a comment</comment>
     </data>
-                
+
     There are any number of "resheader" rows that contain simple 
     name/value pairs.
-    
+
     Each data row contains a name, and value. The row also contains a 
     type or mimetype. Type corresponds to a .NET class that support 
     text/value conversion through the TypeConverter architecture. 
     Classes that don't support this are serialized and stored with the 
     mimetype set.
-    
+
     The mimetype is used for serialized objects, and tells the 
     ResXResourceReader how to depersist the object. This is currently not 
     extensible. For a given mimetype the value must be set accordingly:
-    
+
     Note - application/x-microsoft.net.object.binary.base64 is the format 
     that the ResXResourceWriter will generate, however the reader can 
     read any of the formats listed below.
-    
+
     mimetype: application/x-microsoft.net.object.binary.base64
     value   : The object must be serialized with 
             : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
             : and then encoded with base64 encoding.
-    
+
     mimetype: application/x-microsoft.net.object.soap.base64
     value   : The object must be serialized with 
             : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
@@ -357,4 +357,7 @@ Use '/?' or '/h' to see the help message.</value>
   <data name="MSG_SonarCloudDetected_SkipVersionCheck" xml:space="preserve">
     <value>SonarCloud detected, skipping server version check.</value>
   </data>
+  <data name="ERR_DotNetAnalyzersNotFound" xml:space="preserve">
+    <value>Could not find any dotnet analyzer plugin on the server (SonarQube/SonarCloud)!</value>
+  </data>
 </root>