Improved error message

Author: PawelGerr

src/Thinktecture.Runtime.Extensions.AspNetCore/AspNetCore/ModelBinding/ThinktectureModelBinderBase.cs

@@ -127,7 +127,7 @@ private static void CheckKey(ModelBindingContext bindingContext, ValueProviderRe
    {
       if (_disallowDefaultValues && key.Equals(_keyDefaultValue))
       {
-         bindingContext.ModelState.TryAddModelError(bindingContext.ModelName, $"Cannot convert null to type \"{typeof(T).Name}\" because it doesn't allow default values.");
+         bindingContext.ModelState.TryAddModelError(bindingContext.ModelName, $"Cannot convert the value {_keyDefaultValue} to type \"{typeof(T).Name}\" because it doesn't allow default values.");
          return;
       }
 

src/Thinktecture.Runtime.Extensions.Json/Text/Json/Serialization/ThinktectureJsonConverter.cs

@@ -89,7 +89,7 @@ public ThinktectureJsonConverter(JsonSerializerOptions options)
       }
 
       if (_disallowDefaultValues && key.Equals(_keyDefaultValue))
-         throw new JsonException($"Cannot convert null to type \"{typeof(T).Name}\" because it doesn't allow default values.");
+         throw new JsonException($"Cannot convert the value {_keyDefaultValue} to type \"{typeof(T).Name}\" because it doesn't allow default values.");
 
       var validationError = T.Validate(key, null, out var obj);
 

src/Thinktecture.Runtime.Extensions.MessagePack/Formatters/ThinktectureStructMessagePackFormatter.cs

@@ -68,7 +68,7 @@ public T Deserialize(ref MessagePackReader reader, MessagePackSerializerOptions
       }
 
       if (_disallowDefaultValues && key.Equals(_keyDefaultValue))
-         throw new MessagePackSerializationException($"Cannot convert null to type \"{typeof(T).Name}\" because it doesn't allow default values.");
+         throw new MessagePackSerializationException($"Cannot convert the value {_keyDefaultValue} to type \"{typeof(T).Name}\" because it doesn't allow default values.");
 
       return Deserialize(key);
    }

src/Thinktecture.Runtime.Extensions.Newtonsoft.Json/Json/ThinktectureNewtonsoftJsonConverter.cs

@@ -78,7 +78,7 @@ public override void WriteJson(JsonWriter writer, object? value, JsonSerializer
       }
 
       if (_disallowDefaultValues && key.Equals(_keyDefaultValue))
-         throw new JsonException($"Cannot convert null to type \"{typeof(T).Name}\" because it doesn't allow default values.");
+         throw new JsonException($"Cannot convert the value {_keyDefaultValue} to type \"{typeof(T).Name}\" because it doesn't allow default values.");
 
       var validationError = T.Validate(key, null, out var obj);
 

test/Thinktecture.Runtime.Extensions.AspNetCore.Tests/AspNetCore/ModelBinding/ThinktectureModelBinderTests/BindModelAsync.cs

@@ -81,7 +81,7 @@ public void Should_try_bind_keyed_value_object_when_value_is_null_or_default()
                    .Should().Throw<Exception>().WithMessage("Cannot convert null to type \"IntBasedStructValueObject\".");
 
       FluentActions.Invoking(() => Bind<IntBasedStructValueObjectDoesNotAllowDefaultStructs>("0")) // AllowDefaultStructs = true
-                   .Should().Throw<Exception>().WithMessage("Cannot convert null to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
+                   .Should().Throw<Exception>().WithMessage("Cannot convert the value 0 to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
 
       // nullable struct - string
       Bind<StringBasedStructValueObject?>(null).Should().Be(null);

test/Thinktecture.Runtime.Extensions.Json.Tests/Text/Json/Serialization/ThinktectureJsonConverterFactoryTests/ReadJson.cs

@@ -84,7 +84,7 @@ public void Should_try_deserialize_keyed_value_object_when_value_is_null_or_defa
                    .Should().Throw<JsonException>().WithMessage("The JSON value could not be converted to Thinktecture.Runtime.Tests.TestValueObjects.IntBasedStructValueObject. Path: $ | LineNumber: 0 | BytePositionInLine: 4.");
 
       FluentActions.Invoking(() => Deserialize<IntBasedStructValueObjectDoesNotAllowDefaultStructs>("0")) // AllowDefaultStructs = true
-                   .Should().Throw<JsonException>().WithMessage("Cannot convert null to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
+                   .Should().Throw<JsonException>().WithMessage("Cannot convert the value 0 to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
 
       // nullable struct - string
       Deserialize<StringBasedStructValueObject?>("null").Should().Be(null);
@@ -102,7 +102,7 @@ public void Should_try_deserialize_keyed_value_object_when_value_is_null_or_defa
    public void Should_throw_if_AllowDefaultStructs_is_disabled_on_keyed_value_object_and_value_is_null_and_default()
    {
       FluentActions.Invoking(() => Deserialize<GenericClass<IntBasedStructValueObjectDoesNotAllowDefaultStructs>>("{\"Property\": 0 }"))
-                   .Should().Throw<JsonException>().WithMessage("Cannot convert null to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
+                   .Should().Throw<JsonException>().WithMessage("Cannot convert the value 0 to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
 
       FluentActions.Invoking(() => Deserialize<GenericClass<StringBasedStructValueObject>>("{\"Property\": null }"))
                    .Should().Throw<JsonException>().WithMessage("Cannot convert null to type \"StringBasedStructValueObject\" because it doesn't allow default values.");
@@ -315,7 +315,7 @@ public void Should_throw_if_complex_value_object_property_has_AllowDefaultStruct
                    .Should().NotThrow();
 
       FluentActions.Invoking(() => Deserialize<ComplexValueObjectDoesNotAllowDefaultStructsWithIntBasedStruct>("{ \"Property\": 0 }"))
-                   .Should().Throw<JsonException>().WithMessage("Cannot convert null to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
+                   .Should().Throw<JsonException>().WithMessage("Cannot convert the value 0 to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
 
       FluentActions.Invoking(() => Deserialize<ComplexValueObjectDoesNotAllowDefaultStructsWithStringBasedStruct>("{ \"Property\": null }"))
                    .Should().Throw<JsonException>().WithMessage("Cannot convert null to type \"StringBasedStructValueObject\" because it doesn't allow default values.");

test/Thinktecture.Runtime.Extensions.MessagePack.Tests/Formatters/ThinktectureMessagePackFormatterTests/RoundtripSerialize.cs

@@ -96,7 +96,7 @@ public void Should_try_deserialize_keyed_value_object_when_value_is_null_or_defa
 
       FluentActions.Invoking(() => RoundTrip(0, IntBasedStructValueObjectDoesNotAllowDefaultStructs.Create(-1))) // AllowDefaultStructs = true
                    .Should().Throw<MessagePackSerializationException>()
-                   .WithInnerException<MessagePackSerializationException>().WithMessage("Cannot convert null to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
+                   .WithInnerException<MessagePackSerializationException>().WithMessage("Cannot convert the value 0 to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
 
       // nullable struct - string
       RoundTrip((object)null, (StringBasedStructValueObject?)null);
@@ -117,7 +117,7 @@ public void Should_throw_if_AllowDefaultStructs_is_disabled_on_keyed_value_objec
    {
       FluentActions.Invoking(() => RoundTrip(new GenericClass<int>(0), (GenericClass<IntBasedStructValueObjectDoesNotAllowDefaultStructs>)null))
                    .Should().Throw<MessagePackSerializationException>()
-                   .WithInnerException<MessagePackSerializationException>().WithMessage("Cannot convert null to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
+                   .WithInnerException<MessagePackSerializationException>().WithMessage("Cannot convert the value 0 to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
 
       FluentActions.Invoking(() => RoundTrip(new GenericClass<object>(null), (GenericClass<StringBasedStructValueObject>)null))
                    .Should().Throw<MessagePackSerializationException>()
@@ -367,7 +367,7 @@ public void Should_throw_if_complex_value_object_property_has_AllowDefaultStruct
 
       FluentActions.Invoking(() => RoundTrip(new GenericClass<int>(0), ComplexValueObjectDoesNotAllowDefaultStructsWithIntBasedStruct.Create(IntBasedStructValueObjectDoesNotAllowDefaultStructs.Create(0))))
                    .Should().Throw<MessagePackSerializationException>()
-                   .WithInnerException<MessagePackSerializationException>().WithMessage("Cannot convert null to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
+                   .WithInnerException<MessagePackSerializationException>().WithMessage("Cannot convert the value 0 to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
 
       FluentActions.Invoking(() => RoundTrip(new GenericClass<object>(null), ComplexValueObjectDoesNotAllowDefaultStructsWithStringBasedStruct.Create(StringBasedStructValueObject.Create(""))))
                    .Should().Throw<MessagePackSerializationException>()

test/Thinktecture.Runtime.Extensions.Newtonsoft.Json.Tests/Json/ThinktectureNewtonsoftJsonConverterTests/ReadJson.cs

@@ -85,7 +85,7 @@ public void Should_try_deserialize_keyed_value_object_when_value_is_null_or_defa
                    .Should().Throw<JsonException>().WithMessage("Error converting value {null} to type 'System.Int32'. Path '', line 1, position 4.");
 
       FluentActions.Invoking(() => Deserialize<IntBasedStructValueObjectDoesNotAllowDefaultStructs>("0")) // AllowDefaultStructs = true
-                   .Should().Throw<JsonException>().WithMessage("Cannot convert null to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
+                   .Should().Throw<JsonException>().WithMessage("Cannot convert the value 0 to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
 
       // nullable struct - string
       Deserialize<StringBasedStructValueObject?>("null").Should().Be(null);
@@ -270,7 +270,7 @@ public void Should_throw_if_complex_value_object_property_has_AllowDefaultStruct
                    .Should().NotThrow();
 
       FluentActions.Invoking(() => Deserialize<ComplexValueObjectDoesNotAllowDefaultStructsWithIntBasedStruct>("{ \"Property\": 0 }"))
-                   .Should().Throw<JsonException>().WithMessage("Cannot convert null to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
+                   .Should().Throw<JsonException>().WithMessage("Cannot convert the value 0 to type \"IntBasedStructValueObjectDoesNotAllowDefaultStructs\" because it doesn't allow default values.");
 
       FluentActions.Invoking(() => Deserialize<ComplexValueObjectDoesNotAllowDefaultStructsWithStringBasedStruct>("{ \"Property\": null }"))
                    .Should().Throw<JsonException>().WithMessage("Cannot convert null to type \"StringBasedStructValueObject\" because it doesn't allow default values.");