Set DiagnosticMessage defaults

Refactor `GetDiagnosticSource` into `MakeDiagnostic`
which sets the defaults.

Author: mbg

csharp/autobuilder/Semmle.Autobuild.CSharp/CSharpAutobuilder.cs

@@ -134,41 +134,36 @@ protected override void AutobuildFailureDiagnostic()
                 // otherwise, we just report that the one script we found didn't work
                 if (this.buildCommandAutoRule.CandidatePaths.Count() > 1)
                 {
-                    var source = GetDiagnosticSource("multiple-build-scripts", "There are multiple potential build scripts");
-                    message = new DiagnosticMessage(source)
-                    {
-                        MarkdownMessage =
-                            "CodeQL found multiple potential build scripts for your project and " +
-                            $"attempted to run `{buildCommandAutoRule.ScriptPath}`, which failed. " +
-                            "This may not be the right build script for your project. " +
-                            "You can specify which build script to use by providing a suitable build command for your project."
-                    };
+                    message = MakeDiagnostic("multiple-build-scripts", "There are multiple potential build scripts");
+                    message.MarkdownMessage =
+                        "CodeQL found multiple potential build scripts for your project and " +
+                        $"attempted to run `{buildCommandAutoRule.ScriptPath}`, which failed. " +
+                        "This may not be the right build script for your project. " +
+                        "You can specify which build script to use by providing a suitable build command for your project.";
                 }
                 else
                 {
-                    var source = GetDiagnosticSource("script-failure", "Unable to build project using build script");
-                    message = new DiagnosticMessage(source)
-                    {
-                        MarkdownMessage =
-                            "CodeQL attempted to build your project using a script located at " +
-                            $"`{buildCommandAutoRule.ScriptPath}`, which failed. " +
-                            "You can manually specify a suitable build command for your project."
-                    };
+                    message = MakeDiagnostic("script-failure", "Unable to build project using build script");
+                    message.MarkdownMessage =
+                        "CodeQL attempted to build your project using a script located at " +
+                        $"`{buildCommandAutoRule.ScriptPath}`, which failed. " +
+                        "You can manually specify a suitable build command for your project.";
                 }
 
                 message.Severity = DiagnosticMessage.TspSeverity.Error;
                 Diagnostic(message);
             }
+
             // both dotnet and msbuild builds require project or solution files; if we haven't found any
             // then neither of those rules would've worked
             if (this.ProjectsOrSolutionsToBuild.Count == 0)
             {
-                var source = GetDiagnosticSource("no-projects-or-solutions", "No project or solutions files found");
-                var message = new DiagnosticMessage(source)
-                {
-                    PlaintextMessage = "CodeQL could not find any project or solution files in your repository.",
-                    Severity = DiagnosticMessage.TspSeverity.Error
-                };
+                var message = MakeDiagnostic("no-projects-or-solutions", "No project or solutions files found");
+                message.PlaintextMessage = "CodeQL could not find any project or solution files in your repository.";
+                message.Severity = DiagnosticMessage.TspSeverity.Error;
+
+                Diagnostic(message);
+            }
 
                 Diagnostic(message);
             }

csharp/autobuilder/Semmle.Autobuild.Shared/Autobuilder.cs

@@ -319,14 +319,21 @@ void exitCallback(int ret, string msg, bool silent)
         public abstract BuildScript GetBuildScript();
 
         /// <summary>
-        /// Constructs a standard <see cref="DiagnosticMessage.TspSource" /> for some message
-        /// <see cref="id" /> with a human-friendly <see cref="name" />.
+        /// Constructs a standard <see cref="DiagnosticMessage" /> for some message with
+        /// <see cref="id" /> and a human-friendly <see cref="name" />.
         /// </summary>
         /// <param name="id">The last part of the message id.</param>
         /// <param name="name">The human-friendly description of the message.</param>
-        /// <returns>The resulting <see cref="DiagnosticMessage.TspSource" />.</returns>
-        protected DiagnosticMessage.TspSource GetDiagnosticSource(string id, string name) =>
-            new($"{this.Options.Language.UpperCaseName.ToLower()}/autobuilder/{id}", name);
+        /// <returns>The resulting <see cref="DiagnosticMessage" />.</returns>
+        protected DiagnosticMessage MakeDiagnostic(string id, string name)
+        {
+            DiagnosticMessage diag = new(new($"{this.Options.Language.UpperCaseName.ToLower()}/autobuilder/{id}", name));
+            diag.Source.ExtractorName = Options.Language.UpperCaseName.ToLower();
+            diag.Visibility.StatusPage = true;
+
+            return diag;
+        }
+
 
         /// <summary>
         /// Produces a diagnostic for the tool status page that we were unable to automatically
@@ -336,13 +343,11 @@ protected DiagnosticMessage.TspSource GetDiagnosticSource(string id, string name
         /// </summary>
         protected virtual void AutobuildFailureDiagnostic()
         {
-            var message = new DiagnosticMessage(GetDiagnosticSource("autobuild-failure", "Unable to build project"))
-            {
-                PlaintextMessage =
-                    "We were unable to automatically build your project. " +
-                    "You can manually specify a suitable build command for your project.",
-                Severity = DiagnosticMessage.TspSeverity.Error
-            };
+            var message = MakeDiagnostic("autobuild-failure", "Unable to build project");
+            message.PlaintextMessage =
+                "We were unable to automatically build your project. " +
+                "You can manually specify a suitable build command for your project.";
+            message.Severity = DiagnosticMessage.TspSeverity.Error;
 
             Diagnostic(message);
         }