Found with dotnet-trace that GetDiagnostics takes half of the time.

Added the "DisableDiagnostics" option and removed the "DisableCompilationErrors" option.
Default is false.

Author: TiLied

CSharpToJavaScript/CSTOJS.cs

@@ -62,20 +62,22 @@ public static FileData[] Translate(FileData[] files, MetadataReference[]? refere
 
 			SemanticModel _model = compilation.GetSemanticModel(trees[i]);
 
-			ImmutableArray<Diagnostic> diagnostics = _model.GetDiagnostics();
-			for (int j = 0; j < diagnostics.Length; j++)
+			if (files[i].OptionsForFile.DisableDiagnostics == false)
 			{
-				if (files[i].OptionsForFile.Debug)
-					Log.WarningLine(diagnostics[j].ToString());
-
-				//Print an error if compilation fails.
-				if (diagnostics[j].Severity == DiagnosticSeverity.Error)
+				ImmutableArray<Diagnostic> diagnostics = _model.GetDiagnostics();
+				for (int j = 0; j < diagnostics.Length; j++)
 				{
-					if (files[i].OptionsForFile.DisableCompilationErrors == false)
+					if (diagnostics[j].Severity == DiagnosticSeverity.Hidden && files[i].OptionsForFile.Debug == true)
+						Log.WriteLine(diagnostics[j].ToString());
+					else if (diagnostics[j].Severity == DiagnosticSeverity.Info && files[i].OptionsForFile.Debug == true)
+						Log.InfoLine(diagnostics[j].ToString());
+					else if (diagnostics[j].Severity == DiagnosticSeverity.Warning)
+						Log.WarningLine(diagnostics[i].ToString());
+					else if (diagnostics[j].Severity == DiagnosticSeverity.Error)
 						Log.ErrorLine(diagnostics[i].ToString());
 				}
 			}
-
+			
 			SyntaxNode _root = trees[i].GetRoot();
 
 			WithSemanticRewriter _withSemanticRewriter = new(_model, files[i].OptionsForFile);

CSharpToJavaScript/CSTOJSOptions.cs

@@ -22,20 +22,23 @@ public class CSTOJSOptions
 	/// Default: <c>false</c>
 	/// </value>
 	public bool Debug { get; set; } = false;
+
 	/// <summary>
-	/// Useful for the tests.
+	/// Getting diagnostics is expensive. 
+	/// Enable if you want faster translation.
 	/// </summary>
 	/// <remarks>
 	/// <blockquote class="NOTE"><h5>NOTE</h5>
 	/// <para>
-	/// cstojs_options.xml: &lt;Option DisableCompilationErrors=&quot;false&quot; /&gt;
+	/// cstojs_options.xml: &lt;Option DisableDiagnostics=&quot;false&quot; /&gt;
 	/// </para>
 	/// </blockquote>
+	/// <para><see href = "https://learn.microsoft.com/en-us/dotnet/api/microsoft.codeanalysis.semanticmodel.getdiagnostics?view=roslyn-dotnet-4.13.0#remarks"><em>See remarks.</em></see></para>
 	/// </remarks>
 	/// <value>
 	/// Default: <c>false</c>
 	/// </value>
-	public bool DisableCompilationErrors { get; set; } = false;
+	public bool DisableDiagnostics { get; set; } = false;
 
 	/// <summary>
 	/// Self-explanatory, Use <c>var</c> over <c>let</c>.
@@ -163,7 +166,7 @@ public class CSTOJSOptions
 	/// Default: <c>new()</c>
 	/// </value>
 	public StringBuilder AddSBAtTheBottom { get; set; } = new();
-
+	
 	/// <summary>
 	/// Creates new default options. See <see cref="CSTOJSOptions" />.
 	/// </summary>