Compare updated template evaluator (#4092)

src/Sdk/WorkflowParser/WorkflowValidationException.cs

@@ -0,0 +1,45 @@
+#nullable enable
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.Serialization;
+
+namespace GitHub.Actions.WorkflowParser
+{
+    public class WorkflowValidationException : Exception
+    {
+        public WorkflowValidationException()
+            : this(WorkflowStrings.WorkflowNotValid())
+        {
+        }
+
+        public WorkflowValidationException(IEnumerable<WorkflowValidationError> errors)
+            : this(WorkflowStrings.WorkflowNotValidWithErrors(string.Join(" ", (errors ?? Enumerable.Empty<WorkflowValidationError>()).Take(ErrorCount).Select(e => e.Message))))
+        {
+            m_errors = new List<WorkflowValidationError>(errors ?? Enumerable.Empty<WorkflowValidationError>());
+        }
+
+        public WorkflowValidationException(String message)
+            : base(message)
+        {
+        }
+
+        public WorkflowValidationException(
+            String message,
+            Exception innerException)
+            : base(message, innerException)
+        {
+        }
+
+        internal IReadOnlyList<WorkflowValidationError> Errors => (m_errors ?? new List<WorkflowValidationError>()).AsReadOnly();
+
+        private List<WorkflowValidationError>? m_errors;
+
+        /// <summary>
+        /// Previously set to 2 when there were UI limitations.
+        /// Setting this to 10 to increase the number of errors returned from parser.
+        /// </summary>
+        private const int ErrorCount = 10;
+    }
+}