Compare updated template evaluator (#4092)

src/Sdk/WorkflowParser/Conversion/TemplateTokenExtensions.cs

@@ -0,0 +1,76 @@
+#nullable disable // Consider removing in the future to minimize likelihood of NullReferenceException; refer https://learn.microsoft.com/en-us/dotnet/csharp/nullable-references
+
+using System;
+using GitHub.Actions.Expressions.Data;
+using GitHub.Actions.WorkflowParser.ObjectTemplating.Tokens;
+
+namespace GitHub.Actions.WorkflowParser.Conversion
+{
+    internal static class TemplateTokenExtensions
+    {
+        public static ArrayExpressionData ToExpressionData(this SequenceToken sequence)
+        {
+            var token = sequence as TemplateToken;
+            var expressionData = token.ToExpressionData();
+            return expressionData.AssertArray("converted sequence token");
+        }
+
+        public static DictionaryExpressionData ToExpressionData(this MappingToken mapping)
+        {
+            var token = mapping as TemplateToken;
+            var expressionData = token.ToExpressionData();
+            return expressionData.AssertDictionary("converted mapping token");
+        }
+
+        public static ExpressionData ToExpressionData(this TemplateToken token)
+        {
+            switch (token.Type)
+            {
+                case TokenType.Mapping:
+                    var mapping = token as MappingToken;
+                    var dictionary = new DictionaryExpressionData();
+                    if (mapping.Count > 0)
+                    {
+                        foreach (var pair in mapping)
+                        {
+                            var keyLiteral = pair.Key.AssertString("dictionary context data key");
+                            var key = keyLiteral.Value;
+                            var value = pair.Value.ToExpressionData();
+                            dictionary.Add(key, value);
+                        }
+                    }
+                    return dictionary;
+
+                case TokenType.Sequence:
+                    var sequence = token as SequenceToken;
+                    var array = new ArrayExpressionData();
+                    if (sequence.Count > 0)
+                    {
+                        foreach (var item in sequence)
+                        {
+                            array.Add(item.ToExpressionData());
+                        }
+                    }
+                    return array;
+
+                case TokenType.Null:
+                    return null;
+
+                case TokenType.Boolean:
+                    var boolean = token as BooleanToken;
+                    return new BooleanExpressionData(boolean.Value);
+
+                case TokenType.Number:
+                    var number = token as NumberToken;
+                    return new NumberExpressionData(number.Value);
+
+                case TokenType.String:
+                    var stringToken = token as StringToken;
+                    return new StringExpressionData(stringToken.Value);
+
+                default:
+                    throw new NotSupportedException($"Unexpected {nameof(TemplateToken)} type '{token.Type}'");
+            }
+        }
+    }
+}