Simplified tests for Populate() issue with no operand attributes and resolved the error.

Author: jpdillingham

Utility.CommandLine.Arguments.Tests/Arguments.cs

@@ -554,21 +554,9 @@ public class TestClassWithNoProperties
         ///     containing a single argument/value pair, and with a Type containing no properties.
         /// </summary>
         [Fact]
-        public void PopulateArguments()
-        {
-            Exception ex = Record.Exception(() => CommandLine.Arguments.Populate(GetType(), "--hello world"));
-
-            Assert.Null(ex);
-        }
-
-        /// <summary>
-        ///     Tests the <see cref="Utility.CommandLine.Arguments.Populate(Type, string)"/> method with an explicit string
-        ///     containing two operands, and with a Type containing no properties.
-        /// </summary>
-        [Fact]
-        public void PopulateOperands()
+        public void Populate()
         {
-            Exception ex = Record.Exception(() => CommandLine.Arguments.Populate(GetType(), "one two"));
+            Exception ex = Record.Exception(() => CommandLine.Arguments.Populate(GetType(), "--hello world one two"));
 
             Assert.Null(ex);
         }

Utility.CommandLine.Arguments/Arguments.cs

@@ -312,13 +312,18 @@ public static void Populate(Type type, Arguments arguments)
 
             PropertyInfo operandsProperty = GetOperandsProperty(type);
 
-            if (operandsProperty.PropertyType.IsAssignableFrom(typeof(List<string>)))
+            // check to ensure the target class has a property marked with the Operands attribute; if not GetOperandsProperty()
+            // will return null.
+            if (operandsProperty != default(PropertyInfo))
             {
-                operandsProperty.SetValue(null, arguments.OperandList);
-            }
-            else
-            {
-                operandsProperty.SetValue(null, arguments.OperandList.ToArray());
+                if (operandsProperty.PropertyType.IsAssignableFrom(typeof(List<string>)))
+                {
+                    operandsProperty.SetValue(null, arguments.OperandList);
+                }
+                else
+                {
+                    operandsProperty.SetValue(null, arguments.OperandList.ToArray());
+                }
             }
         }
 
@@ -458,7 +463,7 @@ private static PropertyInfo GetOperandsProperty(Type type)
                     .Any(a => a.AttributeType.Name == typeof(OperandsAttribute).Name))
                         .FirstOrDefault();
 
-            if (property.PropertyType != typeof(string[]) && property.PropertyType != typeof(List<string>))
+            if (property != default(PropertyInfo) && property.PropertyType != typeof(string[]) && property.PropertyType != typeof(List<string>))
             {
                 throw new InvalidCastException("The target for the Operands attribute must be of string[] or List<string>.");
             }