source code generator now aborts if there are errors in Actions.

Previously invalid yarn actions would still get processed and codegen to register them would happen.
The idea being we could flag "hey we know there is an action but it's in a bad state".
However this could cause compilation errors in the generated source code which is quite annoying to deal with.
So now warning still get to slip through and generate a "hey this has issues", but errors do not.

Author: McJones

Editor/Analysis/ActionsRegistrationGenerator~/ActionsGenerator.cs

@@ -117,6 +117,7 @@ public void Execute(GeneratorExecutionContext context)
             output.WriteLine($"Unable to determine project location on disk. Settings values will be ignored and codegen will occur");
         }
 
+        bool hasCriticalActionErrors = false;
         try
         {
             output.WriteLine("Source code generation for assembly " + context.Compilation.AssemblyName);
@@ -188,7 +189,6 @@ public void Execute(GeneratorExecutionContext context)
             {
                 output.WriteLine($"Not generating registration code for {context.Compilation.AssemblyName}: we've been told to exclude it, because its name begins with one of these prefixes: {string.Join(", ", prefixesToIgnore)}");
                 return;
-
             }
 
             if (!(context.Compilation is CSharpCompilation compilation))
@@ -227,14 +227,14 @@ public void Execute(GeneratorExecutionContext context)
                     {
                         output.WriteLine($"Flagging '{action.Name}' ({action.MethodName}): {diagnostic}");
                         action.ContainsErrors = true;
+                    
+                        if (diagnostic.Severity == DiagnosticSeverity.Error)
+                        {
+                            hasCriticalActionErrors = true;
+                        }
                     }
                 }
 
-                if (diagnostics.Count > 0)
-                {
-                    continue;
-                }
-
                 // Commands are parsed as whitespace, so spaces in the command name
                 // would render the command un-callable.
                 if (action.Name.Any(x => Char.IsWhiteSpace(x)))
@@ -261,6 +261,13 @@ public void Execute(GeneratorExecutionContext context)
                 output.WriteLine($"Action {action.Name}: {action.SourceFileName}:{action.Declaration?.GetLocation()?.GetLineSpan().StartLinePosition.Line} ({action.Type})");
             }
 
+            if (hasCriticalActionErrors)
+            {
+                stopwatch.Stop();
+                output.WriteLine($"Critical issues were encountered in the actions, aborting code generation, stopping analysis after {stopwatch.Elapsed.TotalMilliseconds}ms");
+                return;
+            }
+
             output.Write($"Generating source code...");
 
             var source = Analyser.GenerateRegistrationFileSource(actions);