In ASP.NET 7, IEnumerable<> controller parameters do not bind from request body by default

[0x03BB]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

In ASP.NET 7, a controller with an IEnumerable<> parameter is not bound from the body of the request by default. An empty array is seen by the controller. This worked in ASP.NET 6.

[HttpPost]
public IActionResult Post(IEnumerable<WeatherForecast> forecasts)
{
}

If the [FromBody] attribute is added to the parameter or List<> is used instead, the binding works. The linked GitHub project demonstrates this.

Expected Behavior

An IEnumerable<> parameter should be bound from the body by default, as it was in ASP.NET 6.

Steps To Reproduce

https://github.com/0x03BB/ParameterBindingIssue

Exceptions (if any)

No response

.NET Version

7.0.100

Anything else?

Using Visual Studio 17.4.1
dotnet info.txt

[davidfowl]

@brunolins16 This might have to do with the change around inferring services implicitly.

[brunolins16]

@brunolins16 This might have to do with the change around inferring services implicitly.

Ohh! Let me take a look.

[brunolins16]

Sadly ☹️, you are right, the call to IServiceProviderIsService.IsService return true for IEnumerable<> types.

https://github.com/dotnet/runtime/blob/d15a19fd4a9dd21fb768b6de4870a2d80acb3669/src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceLookup/CallSiteFactory.cs#L555