Toolshed refactor (#33598)

* Content changes for engine toolshed PR

* add contains command

* more permissive commands

Content.IntegrationTests/Tests/Toolshed/ToolshedTest.cs

@@ -74,15 +74,15 @@ public abstract class ToolshedTest : IInvocationContext
         return (T) res!;
     }
 
-    protected void ParseCommand(string command, Type? inputType = null, Type? expectedType = null, bool once = false)
+    protected void ParseCommand(string command, Type? inputType = null, Type? expectedType = null)
     {
         var parser = new ParserContext(command, Toolshed);
-        var success = CommandRun.TryParse(false, parser, inputType, expectedType, once, out _, out _, out var error);
+        var success = CommandRun.TryParse(parser, inputType, expectedType, out _);
 
-        if (error is not null)
-            ReportError(error);
+        if (parser.Error is not null)
+            ReportError(parser.Error);
 
-        if (error is null)
+        if (parser.Error is null)
             Assert.That(success, $"Parse failed despite no error being reported. Parsed {command}");
     }
 
@@ -153,11 +153,28 @@ public abstract class ToolshedTest : IInvocationContext
         return _errors;
     }
 
+    public bool HasErrors => _errors.Count > 0;
+
     public void ClearErrors()
     {
         _errors.Clear();
     }
 
+    public object? ReadVar(string name)
+    {
+        return Variables.GetValueOrDefault(name);
+    }
+
+    public void WriteVar(string name, object? value)
+    {
+        Variables[name] = value;
+    }
+
+    public IEnumerable<string> GetVars()
+    {
+        return Variables.Keys;
+    }
+
     public Dictionary<string, object?> Variables { get; } = new();
 
     protected void ExpectError(Type err)