Porting over unit tests for ViewDataDictionary.Eval

Partial fix for #453

src/Microsoft.AspNet.Mvc.Core/Properties/Resources.Designer.cs

@@ -443,7 +443,7 @@ namespace Microsoft.AspNet.Mvc.Core
         }
 
         /// <summary>
-        /// The value cannot be null or empty.
+        /// Value cannot be null or empty.
         /// </summary>
         internal static string ArgumentCannotBeNullOrEmpty
         {
@@ -451,7 +451,7 @@ namespace Microsoft.AspNet.Mvc.Core
         }
 
         /// <summary>
-        /// The value cannot be null or empty.
+        /// Value cannot be null or empty.
         /// </summary>
         internal static string FormatArgumentCannotBeNullOrEmpty()
         {

src/Microsoft.AspNet.Mvc.Core/Resources.resx

@@ -199,7 +199,7 @@
     <value>The action descriptor must be of type '{0}'.</value>
   </data>
   <data name="ArgumentCannotBeNullOrEmpty" xml:space="preserve">
-    <value>The value cannot be null or empty.</value>
+    <value>Value cannot be null or empty.</value>
   </data>
   <data name="PropertyOfTypeCannotBeNull" xml:space="preserve">
     <value>The '{0}' property of '{1}' must not be null.</value>

test/Microsoft.AspNet.Mvc.Core.Test/ControllerTests.cs

@@ -96,8 +96,8 @@ namespace Microsoft.AspNet.Mvc.Test
             var controller = new Controller();
 
             // Act & Assert
-            ExceptionAssert.ThrowsArgument(
-                () => controller.Redirect(url: url), "url", "The value cannot be null or empty");
+            ExceptionAssert.ThrowsArgumentNullOrEmpty(
+                () => controller.Redirect(url: url), "url");
         }
 
         [Theory]
@@ -109,8 +109,8 @@ namespace Microsoft.AspNet.Mvc.Test
             var controller = new Controller();
 
             // Act & Assert
-            ExceptionAssert.ThrowsArgument(
-                () => controller.RedirectPermanent(url: url), "url", "The value cannot be null or empty");
+            ExceptionAssert.ThrowsArgumentNullOrEmpty(
+                () => controller.RedirectPermanent(url: url), "url");
         }
 
         [Fact]

test/Microsoft.AspNet.Mvc.Core.Test/ViewDataDictionaryTest.cs

@@ -2,7 +2,10 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Collections;
+using System.Collections.Generic;
 using Microsoft.AspNet.Mvc.ModelBinding;
+using Microsoft.AspNet.Testing;
 using Moq;
 using Xunit;
 
@@ -156,6 +159,343 @@ namespace Microsoft.AspNet.Mvc.Core
             Assert.IsType<CopyOnWriteDictionary<string, object>>(viewData.Data);
         }
 
+        public static TheoryData<object, string, object> Eval_EvaluatesExpressionsData
+        {
+            get
+            {
+                return new TheoryData<object, string, object>
+                {
+                    {
+                        new { Foo = "Bar" },
+                        "Foo",
+                        "Bar"
+                    },
+                    {
+                        new { Foo = new Dictionary<string, object> { { "Bar", "Baz" } } },
+                        "Foo.Bar",
+                        "Baz"
+                    },
+                    {
+                        new { Foo = new { Bar = "Baz" } },
+                        "Foo.Bar",
+                        "Baz"
+                    }
+                };
+            }
+        }
+
+        [Theory]
+        [MemberData(nameof(Eval_EvaluatesExpressionsData))]
+        public void Eval_EvaluatesExpressions(object model, string expression, object expected)
+        {
+            // Arrange
+            var viewData = GetViewDataDictionary(model);
+
+            // Act
+            var result = viewData.Eval(expression);
+
+            // Assert
+            Assert.Equal(expected, result);
+        }
+
+        [Fact]
+        public void EvalReturnsNullIfExpressionDoesNotMatch()
+        {
+            // Arrange
+            var model = new { Foo = new { Biz = "Baz" } };
+            var viewData = GetViewDataDictionary(model);
+
+            // Act
+            var result = viewData.Eval("Foo.Bar");
+
+            // Assert
+            Assert.Null(result);
+        }
+
+        [Fact]
+        public void EvalEvaluatesDictionaryThenModel()
+        {
+            // Arrange
+            var model = new { Foo = "NotBar" };
+            var viewData = GetViewDataDictionary(model);
+            viewData.Add("Foo", "Bar");
+
+            // Act
+            var result = viewData.Eval("Foo");
+
+            // Assert
+            Assert.Equal("Bar", result);
+        }
+
+        [Fact]
+        public void EvalReturnsValueJustAdded()
+        {
+            // Arrange
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
+            viewData.Add("Foo", "Blah");
+
+            // Act
+            var result = viewData.Eval("Foo");
+
+            // Assert
+            Assert.Equal("Blah", result);
+        }
+
+        [Fact]
+        public void EvalWithCompoundExpressionReturnsIndexedValue()
+        {
+            // Arrange
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
+            viewData.Add("Foo.Bar", "Baz");
+
+            // Act
+            var result = viewData.Eval("Foo.Bar");
+
+            // Assert
+            Assert.Equal("Baz", result);
+        }
+
+        [Fact]
+        public void EvalWithCompoundExpressionReturnsPropertyOfAddedObject()
+        {
+            // Arrange
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
+            viewData.Add("Foo", new { Bar = "Baz" });
+
+            // Act
+            var result = viewData.Eval("Foo.Bar");
+
+            // Assert
+            Assert.Equal("Baz", result);
+        }
+
+        [Fact]
+        public void EvalWithCompoundIndexExpressionReturnsEval()
+        {
+            // Arrange
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
+            viewData.Add("Foo.Bar", new { Baz = "Quux" });
+
+            // Act
+            var result = viewData.Eval("Foo.Bar.Baz");
+
+            // Assert
+            Assert.Equal("Quux", result);
+        }
+
+        [Fact]
+        public void EvalWithCompoundIndexAndCompoundExpressionReturnsValue()
+        {
+            // Arrange
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
+            viewData.Add("Foo.Bar", new { Baz = new { Blah = "Quux" } });
+
+            // Act
+            var result = viewData.Eval("Foo.Bar.Baz.Blah");
+
+            // Assert
+            Assert.Equal("Quux", result);
+        }
+
+        // Make sure that dict["foo.bar"] gets chosen before dict["foo"]["bar"]
+        [Fact]
+        public void EvalChoosesValueInDictionaryOverOtherValue()
+        {
+            // Arrange
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider())
+            {
+                {  "Foo", new { Bar = "Not Baz" } },
+                { "Foo.Bar", "Baz" }
+            };
+
+            // Act
+            var result = viewData.Eval("Foo.Bar");
+
+            // Assert
+            Assert.Equal("Baz", result);
+        }
+
+        // Make sure that dict["foo.bar"]["baz"] gets chosen before dict["foo"]["bar"]["baz"]
+        [Fact]
+        public void EvalChoosesCompoundValueInDictionaryOverOtherValues()
+        {
+            // Arrange
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider())
+            {
+                { "Foo", new { Bar = new { Baz = "Not Quux" } } },
+                { "Foo.Bar", new { Baz = "Quux" } }
+            };
+
+            // Act
+            var result = viewData.Eval("Foo.Bar.Baz");
+
+            // Assert
+            Assert.Equal("Quux", result);
+        }
+
+        // Make sure that dict["foo.bar"]["baz"] gets chosen before dict["foo"]["bar.baz"]
+        [Fact]
+        public void EvalChoosesCompoundValueInDictionaryOverOtherValuesWithCompoundProperty()
+        {
+            // Arrange
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider())
+            {
+                { "Foo", new Person() },
+                { "Foo.Bar", new { Baz = "Quux" } }
+            };
+
+            // Act
+            var result = viewData.Eval("Foo.Bar.Baz");
+
+            // Assert
+            Assert.Equal("Quux", result);
+        }
+
+        [Theory]
+        [InlineData(null)]
+        [InlineData("")]
+        public void EvalThrowsIfExpressionIsNullOrEmpty(string expression)
+        {
+            // Arrange
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
+
+            // Act & Assert
+            ExceptionAssert.ThrowsArgumentNullOrEmpty(() => viewData.Eval(expression), "expression");
+        }
+
+        [Fact]
+        public void EvalWithCompoundExpressionAndDictionarySubExpressionChoosesDictionaryValue()
+        {
+            // Arrange
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
+            viewData.Add("Foo", new Dictionary<string, object> { { "Bar", "Baz" } });
+
+            // Act
+            var result = viewData.Eval("Foo.Bar");
+
+            // Assert
+            Assert.Equal("Baz", result);
+        }
+
+        [Fact]
+        public void EvalWithDictionaryAndNoMatchReturnsNull()
+        {
+            // Arrange
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
+            viewData.Add("Foo", new Dictionary<string, object> { { "NotBar", "Baz" } });
+
+            // Act
+            var result = viewData.Eval("Foo.Bar");
+
+            // Assert
+            Assert.Null(result);
+        }
+
+        [Fact]
+        public void EvalWithNestedDictionariesEvalCorrectly()
+        {
+            // Arrange
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
+            viewData.Add("Foo", new Dictionary<string, object> { { "Bar", new Hashtable { { "Baz", "Quux" } } } });
+
+            // Act
+            var result = viewData.Eval("Foo.Bar.Baz");
+
+            // Assert
+            Assert.Equal("Quux", result);
+        }
+
+        [Fact]
+        public void EvalFormatWithNullValueReturnsEmptyString()
+        {
+            // Arrange
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
+
+            // Act
+            var formattedValue = viewData.Eval("foo", "for{0}mat");
+
+            // Assert
+            Assert.Empty(formattedValue);
+        }
+
+        [Fact]
+        public void EvalFormatWithEmptyFormatReturnsViewData()
+        {
+            // Arrange
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
+            viewData["foo"] = "value";
+
+            // Act
+            var formattedValue = viewData.Eval("foo", string.Empty);
+
+            // Assert
+            Assert.Equal("value", formattedValue);
+        }
+
+        [Fact]
+        public void EvalFormatWithFormatReturnsFormattedViewData()
+        {
+            // Arrange
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
+            viewData["foo"] = "value";
+
+            // Act
+            var formattedValue = viewData.Eval("foo", "for{0}mat");
+
+            // Assert
+            Assert.Equal("forvaluemat", formattedValue);
+        }
+
+        [Fact]
+        public void EvalPropertyNamedModel()
+        {
+            // Arrange
+            var model = new TheQueryStringParam
+            {
+                Name = "The Name",
+                Value = "The Value",
+                Model = "The Model",
+            };
+            var viewData = GetViewDataDictionary(model);
+            viewData["Title"] = "Home Page";
+            viewData["Message"] = "Welcome to ASP.NET MVC!";
+
+            // Act
+            var result = viewData.Eval("Model");
+
+            // Assert
+            Assert.Equal("The Model", result);
+        }
+
+        [Fact]
+        public void EvalSubPropertyNamedValueInModel()
+        {
+            // Arrange
+            var model = new TheQueryStringParam
+            {
+                Name = "The Name",
+                Value = "The Value",
+                Model = "The Model",
+            };
+            var viewData = GetViewDataDictionary(model);
+            viewData["Title"] = "Home Page";
+            viewData["Message"] = "Welcome to ASP.NET MVC!";
+
+            // Act
+            var result = viewData.Eval("Value");
+
+            // Assert
+            Assert.Equal("The Value", result);
+        }
+
+        private static ViewDataDictionary GetViewDataDictionary(object model)
+        {
+            return new ViewDataDictionary(new EmptyModelMetadataProvider())
+            {
+                Model = model
+            };
+        }
+
         private class TestModel
         {
         }
@@ -178,5 +518,12 @@ namespace Microsoft.AspNet.Mvc.Core
                 SetModel(value);
             }
         }
+
+        private class TheQueryStringParam
+        {
+            public string Name { get; set; }
+            public string Value { get; set; }
+            public string Model { get; set; }
+        }
     }
 }