fix: support nullable enums

rdavisau · May 10, 2019 · da1683b · da1683b
1 parent fc8fc81
commit da1683b
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Showing 5 changed files with 63 additions and 16 deletions.
diff --git a/src/DumpEditable/EditorRule.cs b/src/DumpEditable/EditorRule.cs
@@ -62,18 +62,32 @@ public static EditorRule ForNestedAnonymousType()
 
         public static EditorRule ForEnums() =>
             EditorRule.For(
-                (_, p) => p.PropertyType.IsEnum,
-                (o, p, get, set) => EditableDumpContainer.DefaultOptions.OptionsEditor(
-                    p.PropertyType.GetEnumValues().OfType<object>(), 
-                    false, 
-                    null)(o,p,get,set));
+                (_, p) => p.PropertyType.IsEnum || p.PropertyType.IsNullableEnum(),
+                (o, p, get, set) =>
+                {
+                    var isNullable = p.PropertyType.IsNullableEnum();
+                    var type = isNullable 
+                        ? Nullable.GetUnderlyingType(p.PropertyType) 
+                        : p.PropertyType;
+
+                    var options = type.GetEnumValues().OfType<object>().ToList();
+
+                    return EditableDumpContainer.DefaultOptions.OptionsEditor(
+                        options,
+                        isNullable 
+                            ? NullableOptionInclusionKind.IncludeAtEnd
+                            : NullableOptionInclusionKind.DontInclude,
+                        null)(o, p, get, set);
+                });
 
         public static EditorRule ForBool() =>
             EditorRule.For(
                 (_, p) => p.PropertyType == typeof(bool) || p.PropertyType == typeof(bool?),
                 (o, p, get, set) => EditableDumpContainer.DefaultOptions.OptionsEditor(
                         new [] { true, false }.OfType<object>(),
-                        p.PropertyType == typeof(bool?),
+                        p.PropertyType == typeof(bool?) 
+                            ? NullableOptionInclusionKind.IncludeAtEnd
+                            : NullableOptionInclusionKind.DontInclude,
                         null)(o, p, get, set));
 
         public static EditorRule ForTypeWithStringBasedEditor<T>(ParseFunc<string, T, bool> parseFunc, bool supportNullable = true, bool supportEnumerable = true)
@@ -95,7 +109,7 @@ public static EditorRule ForTypeWithStringBasedEditor<T>(ParseFunc<string, T, bo
 
                 return ret;
             };
-
+        
         public delegate V ParseFunc<T, U, V>(T input, out U output);
 
         public const string NullString = "(null)";

diff --git a/src/DumpEditable/Editors.cs b/src/DumpEditable/Editors.cs
@@ -5,6 +5,7 @@
 using System.Reflection;
 using LINQPad.Controls;
 using LINQPad.DumpEditable.Helpers;
+using LINQPad.DumpEditable.Models;
 using Microsoft.VisualBasic;
 using Newtonsoft.Json;
 
@@ -54,11 +55,11 @@ public static class Editors
             };
 
         public static Func<object, PropertyInfo, Func<object>, Action<object>, object> ChoicesWithRadioButtons<T>(
-            IEnumerable<T> choices, bool allowNull, Func<T, string> toString = null) =>
-            ChoicesWithRadioButtons(choices.OfType<object>(), allowNull, o => toString((T) o));
+            IEnumerable<T> choices, NullableOptionInclusionKind nullKind, Func<T, string> toString = null) =>
+            ChoicesWithRadioButtons(choices.OfType<object>(), nullKind, o => toString((T) o));
 
         public static Func<object, PropertyInfo, Func<object>, Action<object>, object> ChoicesWithRadioButtons(
-            IEnumerable<object> choices, bool allowNull, Func<object, string> toString = null) =>
+            IEnumerable<object> choices, NullableOptionInclusionKind nullKind, Func<object, string> toString = null) =>
             (o, p, gv, sv) =>
             {
                 var group = Guid.NewGuid().ToString();
@@ -69,22 +70,42 @@ public static class Editors
                         .Select(x => new RadioButton(@group, toString?.Invoke(x) ?? $"{x}", x.Equals(v), b => sv(x)))
                         .ToList();
 
-                if (allowNull)
-                    radioButtons.Add(new RadioButton(@group, NullString, v == null, _ => sv(null)));
+                var nullOption = new RadioButton(@group, NullString, v == null, _ => sv(null));
+                switch (nullKind)
+                {
+                    case NullableOptionInclusionKind.IncludeAtStart:
+                        radioButtons.Insert(0, nullOption);
+                        break;
+
+                    case NullableOptionInclusionKind.IncludeAtEnd:
+                        radioButtons.Add(nullOption);
+                        break;
+                }
 
                 return Util.HorizontalRun((bool)true, (IEnumerable)radioButtons);
             };
 
         public static Func<object, PropertyInfo, Func<object>, Action<object>, object> ChoicesWithHyperlinqs<T>(
-            IEnumerable<T> choices, bool allowNull, Func<T, string> toString = null) =>
+            IEnumerable<T> choices, NullableOptionInclusionKind nullKind, Func<T, string> toString = null) =>
             (o, p, gv, sv) =>
             {
                 var preceding = new object[] {gv(), "["};
                 var trailing = new object[] {"]"};
 
                 var values = choices.Select(x => new Hyperlinq(() => sv(x), toString?.Invoke(x) ?? $"{x}")).ToList();
-                if (allowNull)
-                    values.Add(new Hyperlinq(() => sv(null), NullString ));
+
+                var nullOption = new Hyperlinq(() => sv(null), NullString);
+                
+                switch (nullKind)
+                {
+                    case NullableOptionInclusionKind.IncludeAtStart:
+                        values.Insert(0, nullOption);
+                        break;
+
+                    case NullableOptionInclusionKind.IncludeAtEnd:
+                        values.Add(nullOption);
+                        break;
+                }
 
                 return Util.HorizontalRun(
                     true,

diff --git a/src/DumpEditable/Helpers/TypeExtensions.cs b/src/DumpEditable/Helpers/TypeExtensions.cs
@@ -31,5 +31,8 @@ public static Type GetArrayLikeElementType(this Type type)
                 .Select(t => t.GenericTypeArguments[0]).FirstOrDefault();
             return enumType;
         }
+
+        public static bool IsNullableEnum(this Type t)
+            => (Nullable.GetUnderlyingType(t)?.IsEnum ?? false);
     }
 }
diff --git a/src/DumpEditable/Models/DumpEditableOptions.cs b/src/DumpEditable/Models/DumpEditableOptions.cs
@@ -20,7 +20,7 @@ public class DumpEditableOptions
         public bool AutomaticallyKeepQueryRunning { get; set; }
         public bool FailSilently { get; set; }
 
-        public Func<IEnumerable<object>, bool, Func<object,string>, Func<object, PropertyInfo, Func<object>, Action<object>, object>> OptionsEditor;
+        public Func<IEnumerable<object>, NullableOptionInclusionKind, Func<object,string>, Func<object, PropertyInfo, Func<object>, Action<object>, object>> OptionsEditor;
         public Func<EditorRule.ParseFunc<string, object, bool>, bool, bool, Func<object, PropertyInfo, Func<object>, Action<object>, object>> StringBasedEditor;
     }
 }
diff --git a/src/DumpEditable/Models/NullableOptionInclusionKind.cs b/src/DumpEditable/Models/NullableOptionInclusionKind.cs
@@ -0,0 +1,9 @@
+namespace LINQPad.DumpEditable.Models
+{
+    public enum NullableOptionInclusionKind
+    {
+        DontInclude,
+        IncludeAtStart,
+        IncludeAtEnd
+    }
+}