Configuration binding ignores ErrorOnUnknownConfiguration and throws

[avendel]

Description

According to a breaking change in .NET 8, configuration binding should throw an InvalidOperationException if the value in the configuration can't be converted to the type of value in the model.

To avoid this behavior, the documentation mentions that you can avoid this by setting BinderOptions.ErrorOnUnknownConfiguration to false.

This does not work, though, and an exception is thrown when the configuration value can't be converted to the type in the model.

Reproduction Steps

dotnet new console
dotnet add package Microsoft.Extensions.Configuration
dotnet add package Microsoft.Extensions.Configuration.Binder

using Microsoft.Extensions.Configuration;

var builder = new ConfigurationBuilder();
builder.AddInMemoryCollection([
    // Empty string, can't be converted to integer.
    KeyValuePair.Create<string, string?>("IntegerValue", "")
]);
var configuration = builder.Build();
// This throws an InvalidOperationException.
var options = configuration.Get<TestOptions>(o => o.ErrorOnUnknownConfiguration = false);

// Expect default value of 11
Console.WriteLine(options?.IntegerValue);

public class TestOptions {
    public int IntegerValue { get; set; } = 11;
}

Expected behavior

No exception thrown, according to description in https://learn.microsoft.com/en-us/dotnet/core/compatibility/extensions/8.0/configurationbinder-exceptions#recommended-action.

Actual behavior

Exception thrown when trying to bind configuration to options instance. This will also occur when using .Configure<TOptions> and using IOptions<TOptions> via the DI framework.

Unhandled exception. System.InvalidOperationException: Failed to convert configuration value at 'IntegerValue' to type 'System.Int32'.
 ---> System.ArgumentException:  is not a valid value for Int32. (Parameter 'value')
 ---> System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at System.ComponentModel.BaseNumberConverter.ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, Object value)
   --- End of inner exception stack trace ---
   at System.ComponentModel.BaseNumberConverter.ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, Object value)
   at Microsoft.Extensions.Configuration.ConfigurationBinder.TryConvertValue(Type type, String value, String path, Object& result, Exception& error)
   --- End of inner exception stack trace ---
   at Microsoft.Extensions.Configuration.ConfigurationBinder.BindInstance(Type type, BindingPoint bindingPoint, IConfiguration config, BinderOptions options, Boolean isParentCollection)
   at Microsoft.Extensions.Configuration.ConfigurationBinder.BindProperty(PropertyInfo property, Object instance, IConfiguration config, BinderOptions options)
   at Microsoft.Extensions.Configuration.ConfigurationBinder.BindProperties(Object instance, IConfiguration configuration, BinderOptions options)
   at Microsoft.Extensions.Configuration.ConfigurationBinder.BindInstance(Type type, BindingPoint bindingPoint, IConfiguration config, BinderOptions options, Boolean isParentCollection)
   at Microsoft.Extensions.Configuration.ConfigurationBinder.Get(IConfiguration configuration, Type type, Action`1 configureOptions)
   at Microsoft.Extensions.Configuration.ConfigurationBinder.Get[T](IConfiguration configuration, Action`1 configureOptions)

Regression?

I haven't tested, but I assume so, since this was the reason for the breaking change.

Known Workarounds

No response

Configuration

.NET 8.0.0
Windows 11
x64

Other information

Related issue: #73915

[ghost]

Tagging subscribers to this area: @dotnet/area-extensions-configuration
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

According to a breaking change in .NET 8, configuration binding should throw an InvalidOperationException if the value in the configuration can't be converted to the type of value in the model.

To avoid this behavior, the documentation mentions that you can avoid this by setting BinderOptions.ErrorOnUnknownConfiguration to false.

This does not work, though, and an exception is thrown when the configuration value can't be converted to the type in the model.

Reproduction Steps

dotnet new console
dotnet add package Microsoft.Extensions.Configuration
dotnet add package Microsoft.Extensions.Configuration.Binder

using Microsoft.Extensions.Configuration;

var builder = new ConfigurationBuilder();
builder.AddInMemoryCollection([
    // Empty string, can't be converted to integer.
    KeyValuePair.Create<string, string?>("IntegerValue", "")
]);
var configuration = builder.Build();
// This throws an InvalidOperationException.
var options = configuration.Get<TestOptions>(o => o.ErrorOnUnknownConfiguration = false);

// Expect default value of 11
Console.WriteLine(options?.IntegerValue);

public class TestOptions {
    public int IntegerValue { get; set; } = 11;
}

Expected behavior

No exception thrown, according to description in https://learn.microsoft.com/en-us/dotnet/core/compatibility/extensions/8.0/configurationbinder-exceptions#recommended-action.

Actual behavior

Exception thrown when trying to bind configuration to options instance. This will also occur when using .Configure<TOptions> and using IOptions<TOptions> via the DI framework.

Unhandled exception. System.InvalidOperationException: Failed to convert configuration value at 'IntegerValue' to type 'System.Int32'.
 ---> System.ArgumentException:  is not a valid value for Int32. (Parameter 'value')
 ---> System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at System.ComponentModel.BaseNumberConverter.ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, Object value)
   --- End of inner exception stack trace ---
   at System.ComponentModel.BaseNumberConverter.ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, Object value)
   at Microsoft.Extensions.Configuration.ConfigurationBinder.TryConvertValue(Type type, String value, String path, Object& result, Exception& error)
   --- End of inner exception stack trace ---
   at Microsoft.Extensions.Configuration.ConfigurationBinder.BindInstance(Type type, BindingPoint bindingPoint, IConfiguration config, BinderOptions options, Boolean isParentCollection)
   at Microsoft.Extensions.Configuration.ConfigurationBinder.BindProperty(PropertyInfo property, Object instance, IConfiguration config, BinderOptions options)
   at Microsoft.Extensions.Configuration.ConfigurationBinder.BindProperties(Object instance, IConfiguration configuration, BinderOptions options)
   at Microsoft.Extensions.Configuration.ConfigurationBinder.BindInstance(Type type, BindingPoint bindingPoint, IConfiguration config, BinderOptions options, Boolean isParentCollection)
   at Microsoft.Extensions.Configuration.ConfigurationBinder.Get(IConfiguration configuration, Type type, Action`1 configureOptions)
   at Microsoft.Extensions.Configuration.ConfigurationBinder.Get[T](IConfiguration configuration, Action`1 configureOptions)

Regression?

I haven't tested, but I assume so, since this was the reason for the breaking change.

Known Workarounds

No response

Configuration

.NET 8.0.0
Windows 11
x64

Other information

Related issue: #73915

Author:	avendel
Assignees:	-
Labels:	area-Extensions-Configuration
Milestone:	-

[tarekgh]

Regression?
I haven't tested, but I assume so, since this was the reason for the breaking change.

To clarify, this is not a regression. The current behavior is same as pervious .NET versions behavior.

It looks we missed the case that is using type converters. we need to handle the cases when calling TryConvertValue to check ErrorOnUnknownConfiguration before throwing.

runtime/src/libraries/Microsoft.Extensions.Configuration.Binder/src/ConfigurationBinder.cs

Line 312 in a79c62d

throw error;

runtime/src/libraries/Microsoft.Extensions.Configuration.Binder/src/ConfigurationBinder.cs

Line 923 in a79c62d

throw error;

[galakt]

@tarekgh Hello, any update on this item? Do you have timeline for this fix?

[tarekgh]

@galakt We currently have higher-priority tasks at hand. If you're interested in submitting a pull request for those, we welcome your contribution.

[krmayankk]

We are also running into this issue and can potentially help fix it with some guidance, if no one else is working on this

[vivinjoy]

Can we also get this breaking change for .Net 8 documentation changed? It's currently the same behavior as in .Net 6, where type mismatch errors during configuration binding always throws an error by default.

[tarekgh]

@krmayankk feel free to submit a PR if you are interested. My comment #98231 (comment) explain what need to be done I guess.