File: GenericModelBinderIntegrationTest.cs
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Project: src\src\Mvc\test\Mvc.IntegrationTests\Microsoft.AspNetCore.Mvc.IntegrationTests.csproj (Microsoft.AspNetCore.Mvc.IntegrationTests)
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Diagnostics;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.Abstractions;
using Microsoft.AspNetCore.Mvc.ModelBinding;
 
namespace Microsoft.AspNetCore.Mvc.IntegrationTests;
 
// Integration tests targeting the behavior of the GenericModelBinder and related classes
// with other model binders.
public class GenericModelBinderIntegrationTest
{
    // This isn't an especially useful scenario - but it exercises what happens when you
    // try to use a Collection of something that is bound greedily by model-type.
    //
    // In this example we choose IFormCollection because IFormCollection has a dedicated
    // model binder.
    [Fact]
    public async Task GenericModelBinder_BindsCollection_ElementTypeFromGreedyModelBinder_WithPrefix_Success()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(List<IFormCollection>)
        };
 
        // Need to have a key here so that the GenericModelBinder will recurse to bind elements.
        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString("?parameter.index=10");
        });
 
        var modelState = testContext.ModelState;
 
        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);
 
        // Assert
        Assert.True(modelBindingResult.IsModelSet);
 
        var model = Assert.IsType<List<IFormCollection>>(modelBindingResult.Model);
        var formCollection = Assert.Single(model);
        Assert.NotNull(formCollection);
 
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
        Assert.Empty(modelState);
    }
 
    // This isn't an especially useful scenario - but it exercises what happens when you
    // try to use a Collection of something that is bound greedily by model-type.
    //
    // In this example we choose IFormCollection - because IFormCollection has a dedicated
    // model  binder.
    [Fact]
    public async Task GenericModelBinder_BindsCollection_ElementTypeFromGreedyModelBinder_EmptyPrefix_Success()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(List<IFormCollection>)
        };
        // Need to have a key here so that the GenericModelBinder will recurse to bind elements.
        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString("?index=10");
        });
 
        var modelState = testContext.ModelState;
 
        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);
 
        // Assert
        Assert.True(modelBindingResult.IsModelSet);
 
        var model = Assert.IsType<List<IFormCollection>>(modelBindingResult.Model);
        var formCollection = Assert.Single(model);
        Assert.NotNull(formCollection);
 
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
        Assert.Empty(modelState);
    }
 
    // This isn't an especially useful scenario - but it exercises what happens when you
    // try to use a Collection of something that is bound greedily by model-type.
    //
    // In this example we choose IFormCollection - because IFormCollection has a dedicated
    // model  binder.
    [Fact]
    public async Task GenericModelBinder_BindsCollection_ElementTypeFromGreedyModelBinder_NoData()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(List<IFormCollection>)
        };
 
        // Without a key here so the GenericModelBinder will not recurse to bind elements.
        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString("?");
        });
 
        var modelState = testContext.ModelState;
 
        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);
 
        // Assert
        Assert.True(modelBindingResult.IsModelSet);
 
        var model = Assert.IsType<List<IFormCollection>>(modelBindingResult.Model);
        Assert.Empty(model);
    }
 
    [BindAddress]
    private class Address
    {
    }
 
    private class BindAddressAttribute : Attribute, IBindingSourceMetadata
    {
        public static readonly BindingSource Source = new BindingSource(
            "Address",
            displayName: "Address",
            isGreedy: true,
            isFromRequest: true);
 
        public BindingSource BindingSource
        {
            get
            {
                return Source;
            }
        }
    }
 
    private class AddressBinderProvider : IModelBinderProvider
    {
        public IModelBinder GetBinder(ModelBinderProviderContext context)
        {
            var allowedBindingSource = context.BindingInfo.BindingSource;
            if (allowedBindingSource?.CanAcceptDataFrom(BindAddressAttribute.Source) == true)
            {
                // Binding Sources are opt-in. This model either didn't specify one or specified something
                // incompatible so let other binders run.
                return new AddressBinder();
            }
 
            return null;
        }
    }
 
    private class AddressBinder : IModelBinder
    {
        public Task BindModelAsync(ModelBindingContext bindingContext)
        {
            ArgumentNullException.ThrowIfNull(bindingContext);
 
            Debug.Assert(bindingContext.Result == ModelBindingResult.Failed());
 
            var allowedBindingSource = bindingContext.BindingSource;
            if (allowedBindingSource == null ||
                !allowedBindingSource.CanAcceptDataFrom(BindAddressAttribute.Source))
            {
                // Binding Sources are opt-in. This model either didn't specify one or specified something
                // incompatible so let other binders run.
                return Task.CompletedTask;
            }
 
            bindingContext.Result = ModelBindingResult.Success(new Address());
            return Task.CompletedTask;
        }
    }
 
    // This isn't an especially useful scenario - but it exercises what happens when you
    // try to use a Collection of something that is bound greedily by binding source.
    [Fact]
    public async Task GenericModelBinder_BindsCollection_ElementTypeUsesGreedyModelBinder_WithPrefix_Success()
    {
        // Arrange
        // Need to have a key here so that the GenericModelBinder will recurse to bind elements.
        var testContext = ModelBindingTestHelper.GetTestContext(
            request => request.QueryString = new QueryString("?parameter.index=0"));
 
        var modelState = testContext.ModelState;
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder(
            testContext.MvcOptions,
            new AddressBinderProvider());
 
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(Address[])
        };
 
        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);
 
        // Assert
        Assert.True(modelBindingResult.IsModelSet);
 
        var model = Assert.IsType<Address[]>(modelBindingResult.Model);
        Assert.Single(model);
        Assert.NotNull(model[0]);
 
        Assert.Empty(modelState);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
    }
 
    // Similar to the GenericModelBinder_BindsCollection_ElementTypeUsesGreedyModelBinder_WithPrefix_Success
    // scenario but mis-configured. Model using a BindingSource for which no ModelBinder is enabled.
    [Fact]
    public async Task GenericModelBinder_BindsCollection_ElementTypeUsesGreedyBindingSource_WithPrefix_NullElement()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(Address[])
        };
 
        // Need to have a key here so that the GenericModelBinder will recurse to bind elements.
        var testContext = ModelBindingTestHelper.GetTestContext(
            request => request.QueryString = new QueryString("?parameter.index=0"));
 
        var modelState = testContext.ModelState;
 
        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);
 
        // Assert
        Assert.True(modelBindingResult.IsModelSet);
 
        var model = Assert.IsType<Address[]>(modelBindingResult.Model);
        Assert.Single(model);
        Assert.Null(model[0]);
 
        Assert.Empty(modelState);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
    }
 
    // This is part of a random sampling of scenarios where a GenericModelBinder is used
    // recursively.
    [Fact]
    public async Task GenericModelBinder_BindsArrayOfDictionary_WithPrefix_Success()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(Dictionary<string, int>[])
        };
 
        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString("?parameter[0][0].Key=key0&parameter[0][0].Value=10");
        });
 
        var modelState = testContext.ModelState;
 
        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);
 
        // Assert
        Assert.True(modelBindingResult.IsModelSet);
 
        var model = Assert.IsType<Dictionary<string, int>[]>(modelBindingResult.Model);
        var dictionary = Assert.Single(model);
        var kvp = Assert.Single(dictionary);
        Assert.Equal("key0", kvp.Key);
        Assert.Equal(10, kvp.Value);
 
        Assert.Equal(2, modelState.Count);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
 
        var entry = Assert.Single(modelState, e => e.Key == "parameter[0][0].Key").Value;
        Assert.Equal("key0", entry.AttemptedValue);
        Assert.Equal("key0", entry.RawValue);
 
        entry = Assert.Single(modelState, e => e.Key == "parameter[0][0].Value").Value;
        Assert.Equal("10", entry.AttemptedValue);
        Assert.Equal("10", entry.RawValue);
    }
 
    // This is part of a random sampling of scenarios where a GenericModelBinder is used
    // recursively.
    [Fact]
    public async Task GenericModelBinder_BindsArrayOfDictionary_EmptyPrefix_Success()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(Dictionary<string, int>[])
        };
 
        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString("?[0][0].Key=key0&[0][0].Value=10");
        });
 
        var modelState = testContext.ModelState;
 
        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);
 
        // Assert
        Assert.True(modelBindingResult.IsModelSet);
 
        var model = Assert.IsType<Dictionary<string, int>[]>(modelBindingResult.Model);
        var dictionary = Assert.Single(model);
        var kvp = Assert.Single(dictionary);
        Assert.Equal("key0", kvp.Key);
        Assert.Equal(10, kvp.Value);
 
        Assert.Equal(2, modelState.Count);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
 
        var entry = Assert.Single(modelState, e => e.Key == "[0][0].Key").Value;
        Assert.Equal("key0", entry.AttemptedValue);
        Assert.Equal("key0", entry.RawValue);
 
        entry = Assert.Single(modelState, e => e.Key == "[0][0].Value").Value;
        Assert.Equal("10", entry.AttemptedValue);
        Assert.Equal("10", entry.RawValue);
    }
 
    // This is part of a random sampling of scenarios where a GenericModelBinder is used
    // recursively.
    [Fact]
    public async Task GenericModelBinder_BindsArrayOfDictionary_NoData()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(Dictionary<string, int>[])
        };
 
        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString("?");
        });
 
        var modelState = testContext.ModelState;
 
        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);
 
        // Assert
        Assert.True(modelBindingResult.IsModelSet);
 
        var model = Assert.IsType<Dictionary<string, int>[]>(modelBindingResult.Model);
        Assert.NotNull(model);
        Assert.Empty(model);
 
        Assert.Empty(modelState);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
    }
 
    // This is part of a random sampling of scenarios where a GenericModelBinder is used
    // recursively.
    [Fact]
    public async Task GenericModelBinder_BindsCollectionOfKeyValuePair_WithPrefix_Success()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(ICollection<KeyValuePair<string, int>>)
        };
 
        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString("?parameter[0].Key=key0&parameter[0].Value=10");
        });
 
        var modelState = testContext.ModelState;
 
        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);
 
        // Assert
        Assert.True(modelBindingResult.IsModelSet);
 
        var model = Assert.IsType<List<KeyValuePair<string, int>>>(modelBindingResult.Model);
        var kvp = Assert.Single(model);
        Assert.Equal("key0", kvp.Key);
        Assert.Equal(10, kvp.Value);
 
        Assert.Equal(2, modelState.Count);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
 
        var entry = Assert.Single(modelState, e => e.Key == "parameter[0].Key").Value;
        Assert.Equal("key0", entry.AttemptedValue);
        Assert.Equal("key0", entry.RawValue);
 
        entry = Assert.Single(modelState, e => e.Key == "parameter[0].Value").Value;
        Assert.Equal("10", entry.AttemptedValue);
        Assert.Equal("10", entry.RawValue);
    }
 
    // This is part of a random sampling of scenarios where a GenericModelBinder is used
    // recursively.
    [Fact]
    public async Task GenericModelBinder_BindsCollectionOfKeyValuePair_EmptyPrefix_Success()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(ICollection<KeyValuePair<string, int>>)
        };
 
        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString("?[0].Key=key0&[0].Value=10");
        });
 
        var modelState = testContext.ModelState;
 
        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);
 
        // Assert
        Assert.True(modelBindingResult.IsModelSet);
 
        var model = Assert.IsType<List<KeyValuePair<string, int>>>(modelBindingResult.Model);
        var kvp = Assert.Single(model);
        Assert.Equal("key0", kvp.Key);
        Assert.Equal(10, kvp.Value);
 
        Assert.Equal(2, modelState.Count);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
 
        var entry = Assert.Single(modelState, e => e.Key == "[0].Key").Value;
        Assert.Equal("key0", entry.AttemptedValue);
        Assert.Equal("key0", entry.RawValue);
 
        entry = Assert.Single(modelState, e => e.Key == "[0].Value").Value;
        Assert.Equal("10", entry.AttemptedValue);
        Assert.Equal("10", entry.RawValue);
    }
 
    // This is part of a random sampling of scenarios where a GenericModelBinder is used
    // recursively.
    [Fact]
    public async Task GenericModelBinder_BindsCollectionOfKeyValuePair_NoData()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(ICollection<KeyValuePair<string, int>>)
        };
 
        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString("?");
        });
 
        var modelState = testContext.ModelState;
 
        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);
 
        // Assert
        Assert.True(modelBindingResult.IsModelSet);
 
        var model = Assert.IsType<List<KeyValuePair<string, int>>>(modelBindingResult.Model);
        Assert.NotNull(model);
        Assert.Empty(model);
 
        Assert.Empty(modelState);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
    }
 
    // This is part of a random sampling of scenarios where a GenericModelBinder is used
    // recursively.
    [Fact]
    public async Task GenericModelBinder_BindsDictionaryOfList_WithPrefix_Success()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(Dictionary<string, List<int>>)
        };
 
        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString(
                "?parameter[0].Key=key0&parameter[0].Value[0]=10&parameter[0].Value[1]=11");
        });
 
        var modelState = testContext.ModelState;
 
        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);
 
        // Assert
        Assert.True(modelBindingResult.IsModelSet);
 
        var model = Assert.IsType<Dictionary<string, List<int>>>(modelBindingResult.Model);
        var kvp = Assert.Single(model);
        Assert.Equal("key0", kvp.Key);
        Assert.Equal(new List<int>() { 10, 11 }, kvp.Value);
 
        Assert.Equal(3, modelState.Count);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
 
        var entry = Assert.Single(modelState, e => e.Key == "parameter[0].Key").Value;
        Assert.Equal("key0", entry.AttemptedValue);
        Assert.Equal("key0", entry.RawValue);
 
        entry = Assert.Single(modelState, e => e.Key == "parameter[0].Value[0]").Value;
        Assert.Equal("10", entry.AttemptedValue);
        Assert.Equal("10", entry.RawValue);
 
        entry = Assert.Single(modelState, e => e.Key == "parameter[0].Value[1]").Value;
        Assert.Equal("11", entry.AttemptedValue);
        Assert.Equal("11", entry.RawValue);
    }
 
    // This is part of a random sampling of scenarios where a GenericModelBinder is used
    // recursively.
    [Fact]
    public async Task GenericModelBinder_BindsDictionaryOfList_EmptyPrefix_Success()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(Dictionary<string, List<int>>)
        };
 
        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString("?[0].Key=key0&[0].Value[0]=10&[0].Value[1]=11");
        });
 
        var modelState = testContext.ModelState;
 
        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);
 
        // Assert
        Assert.True(modelBindingResult.IsModelSet);
 
        var model = Assert.IsType<Dictionary<string, List<int>>>(modelBindingResult.Model);
        var kvp = Assert.Single(model);
        Assert.Equal("key0", kvp.Key);
        Assert.Equal(new List<int>() { 10, 11 }, kvp.Value);
 
        Assert.Equal(3, modelState.Count);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
 
        var entry = Assert.Single(modelState, e => e.Key == "[0].Key").Value;
        Assert.Equal("key0", entry.AttemptedValue);
        Assert.Equal("key0", entry.RawValue);
 
        entry = Assert.Single(modelState, e => e.Key == "[0].Value[0]").Value;
        Assert.Equal("10", entry.AttemptedValue);
        Assert.Equal("10", entry.RawValue);
 
        entry = Assert.Single(modelState, e => e.Key == "[0].Value[1]").Value;
        Assert.Equal("11", entry.AttemptedValue);
        Assert.Equal("11", entry.RawValue);
    }
 
    // This is part of a random sampling of scenarios where a GenericModelBinder is used
    // recursively.
    [Fact]
    public async Task GenericModelBinder_BindsDictionaryOfList_NoData()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(Dictionary<string, List<int>>)
        };
 
        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString("?");
        });
 
        var modelState = testContext.ModelState;
 
        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);
 
        // Assert
        Assert.True(modelBindingResult.IsModelSet);
 
        var model = Assert.IsType<Dictionary<string, List<int>>>(modelBindingResult.Model);
        Assert.NotNull(model);
        Assert.Empty(model);
 
        Assert.Empty(modelState);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
    }
}