get rid of the error msg (#8158)

Author: StellaHuang95

Python/Product/PythonTools/PythonTools/Editor/Formatting/PythonFormatter.cs

@@ -59,10 +59,16 @@ string[] extraArgs
         protected abstract string[] GetToolCommandArgs(string documentFilePath, Range range, string[] extraArgs);
 
         protected virtual async Task<string> RunToolAsync(string interpreterExePath, string documentFilePath, Range range, string[] extraArgs) {
+            var args = GetToolCommandArgs(documentFilePath, range, extraArgs);
+
+            if (args == null) { 
+                return "";
+            }
+
             var output = ProcessOutput.RunHiddenAndCapture(
                 interpreterExePath,
                 System.Text.Encoding.UTF8,
-                GetToolCommandArgs(documentFilePath, range, extraArgs)
+                args
             );
 
             await output;

Python/Product/PythonTools/PythonTools/Editor/Formatting/PythonFormatterBlack.cs

@@ -24,7 +24,8 @@ public PythonFormatterBlack() : base("black", false) { }
 
         protected override string[] GetToolCommandArgs(string documentFilePath, Range range, string[] extraArgs) {
             if (range != null) {
-                throw new PythonFormatterRangeNotSupportedException("Black does not support the Format Selection command.");
+                return null;
+                // throw new PythonFormatterRangeNotSupportedException("Black does not support the Format Selection command.");
             }
 
             return new[] { "-m", Package, "--diff", documentFilePath };