// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Collections;
using System.Collections.ObjectModel;
using System.ComponentModel.DataAnnotations;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.Abstractions;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.Extensions.Primitives;

namespace Microsoft.AspNetCore.Mvc.IntegrationTests;

// Integration tests targeting the behavior of the CollectionModelBinder with other model binders.
//
// Note that CollectionModelBinder handles both ICollection{T} and IList{T}
public class CollectionModelBinderIntegrationTest
{
    [Fact]
    public async Task CollectionModelBinder_BindsListOfSimpleType_WithPrefix_Success()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(List<int>)
        };

        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString("?parameter[0]=10&parameter[1]=11");
        });

        var modelState = testContext.ModelState;

        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelBindingResult.IsModelSet);

        var model = Assert.IsType<List<int>>(modelBindingResult.Model);
        Assert.Equal(new List<int>() { 10, 11 }, model);

        Assert.Equal(2, modelState.Count);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);

        var entry = Assert.Single(modelState, kvp => kvp.Key == "parameter[0]").Value;
        Assert.Equal("10", entry.AttemptedValue);
        Assert.Equal("10", entry.RawValue);

        entry = Assert.Single(modelState, kvp => kvp.Key == "parameter[1]").Value;
        Assert.Equal("11", entry.AttemptedValue);
        Assert.Equal("11", entry.RawValue);
    }

    [Theory]
    [InlineData("?prefix[0]=10&prefix[1]=11")]
    [InlineData("?prefix.index=low&prefix.index=high&prefix[low]=10&prefix[high]=11")]
    [InlineData("?prefix.index=index&prefix.index=indexer&prefix[index]=10&prefix[indexer]=11")]
    [InlineData("?prefix.index=index&prefix.index=indexer&prefix[index]=10&prefix[indexer]=11&prefix[extra]=12")]
    public async Task CollectionModelBinder_BindsListOfSimpleType_WithExplicitPrefix_Success(string queryString)
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            BindingInfo = new BindingInfo()
            {
                BinderModelName = "prefix",
            },
            ParameterType = typeof(List<int>)
        };

        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString(queryString);
        });

        var modelState = testContext.ModelState;

        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelBindingResult.IsModelSet);

        var model = Assert.IsType<List<int>>(modelBindingResult.Model);
        Assert.Equal(new List<int>() { 10, 11 }, model);

        Assert.Equal(2, modelState.Count);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
    }

    [Theory]
    [InlineData("?[0]=10&[1]=11")]
    [InlineData("?index=low&index=high&[high]=11&[low]=10")]
    [InlineData("?index=index&index=indexer&[indexer]=11&[index]=10")]
    [InlineData("?index=index&index=indexer&[indexer]=11&[index]=10&[extra]=12")]
    public async Task CollectionModelBinder_BindsCollectionOfSimpleType_EmptyPrefix_Success(string queryString)
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(ICollection<int>)
        };

        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString(queryString);
        });

        var modelState = testContext.ModelState;

        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelBindingResult.IsModelSet);

        var model = Assert.IsType<List<int>>(modelBindingResult.Model);
        Assert.Equal(new List<int> { 10, 11 }, model);

        Assert.Equal(2, modelState.Count);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
    }

    [Fact]
    public async Task CollectionModelBinder_BindsListOfSimpleType_NoData()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(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);
        Assert.Empty(Assert.IsType<List<int>>(modelBindingResult.Model));

        Assert.Empty(modelState);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
    }

    private class Person
    {
        public int Id { get; set; }
    }

    [Theory]
    [InlineData("?[0].Id=10&[1].Id=11")]
    [InlineData("?index=low&index=high&[low].Id=10&[high].Id=11")]
    [InlineData("?parameter[0].Id=10&parameter[1].Id=11")]
    [InlineData("?parameter.index=low&parameter.index=high&parameter[low].Id=10&parameter[high].Id=11")]
    [InlineData("?parameter.index=index&parameter.index=indexer&parameter[index].Id=10&parameter[indexer].Id=11")]
    public async Task CollectionModelBinder_BindsListOfComplexType_ImpliedPrefix_Success(string queryString)
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(List<Person>)
        };

        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString(queryString);
        });

        var modelState = testContext.ModelState;

        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelBindingResult.IsModelSet);

        var model = Assert.IsType<List<Person>>(modelBindingResult.Model);
        Assert.Equal(10, model[0].Id);
        Assert.Equal(11, model[1].Id);

        Assert.Equal(2, modelState.Count);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
    }

    [Theory]
    [InlineData("?prefix[0].Id=10&prefix[1].Id=11")]
    [InlineData("?prefix.index=low&prefix.index=high&prefix[high].Id=11&prefix[low].Id=10")]
    [InlineData("?prefix.index=index&prefix.index=indexer&prefix[indexer].Id=11&prefix[index].Id=10")]
    public async Task CollectionModelBinder_BindsListOfComplexType_ExplicitPrefix_Success(string queryString)
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            BindingInfo = new BindingInfo()
            {
                BinderModelName = "prefix",
            },
            ParameterType = typeof(List<Person>)
        };

        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString(queryString);
        });

        var modelState = testContext.ModelState;

        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelBindingResult.IsModelSet);

        var model = Assert.IsType<List<Person>>(modelBindingResult.Model);
        Assert.Equal(10, model[0].Id);
        Assert.Equal(11, model[1].Id);

        Assert.Equal(2, modelState.Count);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
    }

    [Fact]
    public async Task CollectionModelBinder_BindsListOfComplexType_NoData()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(List<Person>)
        };

        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);
        Assert.Empty(Assert.IsType<List<Person>>(modelBindingResult.Model));

        Assert.Empty(modelState);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
    }

    private class Person2
    {
        public int Id { get; set; }

        [BindRequired]
        public string Name { get; set; }
    }

    [Fact]
    public async Task CollectionModelBinder_BindsListOfComplexType_WithRequiredProperty_WithPrefix_PartialData()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(List<Person2>)
        };

        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString("?parameter[0].Id=10&parameter[1].Id=11");
        });

        var modelState = testContext.ModelState;

        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelBindingResult.IsModelSet);

        var model = Assert.IsType<List<Person2>>(modelBindingResult.Model);
        Assert.Equal(10, model[0].Id);
        Assert.Equal(11, model[1].Id);
        Assert.Null(model[0].Name);
        Assert.Null(model[1].Name);

        Assert.Equal(4, modelState.Count);
        Assert.Equal(2, modelState.ErrorCount);
        Assert.False(modelState.IsValid);

        var entry = Assert.Single(modelState, kvp => kvp.Key == "parameter[0].Id").Value;
        Assert.Equal("10", entry.AttemptedValue);
        Assert.Equal("10", entry.RawValue);

        entry = Assert.Single(modelState, kvp => kvp.Key == "parameter[1].Id").Value;
        Assert.Equal("11", entry.AttemptedValue);
        Assert.Equal("11", entry.RawValue);

        entry = Assert.Single(modelState, kvp => kvp.Key == "parameter[0].Name").Value;
        Assert.Null(entry.RawValue);
        Assert.Equal(ModelValidationState.Invalid, entry.ValidationState);
        var error = Assert.Single(entry.Errors);
        Assert.Equal("A value for the 'Name' parameter or property was not provided.", error.ErrorMessage);

        entry = Assert.Single(modelState, kvp => kvp.Key == "parameter[1].Name").Value;
        Assert.Null(entry.RawValue);
        Assert.Equal(ModelValidationState.Invalid, entry.ValidationState);
        error = Assert.Single(entry.Errors);
        Assert.Equal("A value for the 'Name' parameter or property was not provided.", error.ErrorMessage);
    }

    [Fact]
    public async Task CollectionModelBinder_BindsListOfComplexType_WithRequiredProperty_WithExplicitPrefix_PartialData()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            BindingInfo = new BindingInfo()
            {
                BinderModelName = "prefix",
            },
            ParameterType = typeof(List<Person2>)
        };

        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString("?prefix[0].Id=10&prefix[1].Id=11");
        });

        var modelState = testContext.ModelState;

        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelBindingResult.IsModelSet);

        var model = Assert.IsType<List<Person2>>(modelBindingResult.Model);
        Assert.Equal(10, model[0].Id);
        Assert.Null(model[0].Name);
        Assert.Equal(11, model[1].Id);
        Assert.Null(model[1].Name);

        Assert.Equal(4, modelState.Count);
        Assert.Equal(2, modelState.ErrorCount);
        Assert.False(modelState.IsValid);

        var entry = Assert.Single(modelState, kvp => kvp.Key == "prefix[0].Id").Value;
        Assert.Equal("10", entry.AttemptedValue);
        Assert.Equal("10", entry.RawValue);

        entry = Assert.Single(modelState, kvp => kvp.Key == "prefix[1].Id").Value;
        Assert.Equal("11", entry.AttemptedValue);
        Assert.Equal("11", entry.RawValue);

        entry = Assert.Single(modelState, kvp => kvp.Key == "prefix[0].Name").Value;
        Assert.Null(entry.RawValue);
        Assert.Equal(ModelValidationState.Invalid, entry.ValidationState);

        entry = Assert.Single(modelState, kvp => kvp.Key == "prefix[1].Name").Value;
        Assert.Null(entry.RawValue);
        Assert.Equal(ModelValidationState.Invalid, entry.ValidationState);
    }

    [Fact]
    public async Task CollectionModelBinder_BindsCollectionOfComplexType_WithRequiredProperty_EmptyPrefix_PartialData()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(ICollection<Person2>)
        };

        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString("?[0].Id=10&[1].Id=11");
        });

        var modelState = testContext.ModelState;

        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelBindingResult.IsModelSet);

        var model = Assert.IsType<List<Person2>>(modelBindingResult.Model);
        Assert.Equal(10, model[0].Id);
        Assert.Null(model[0].Name);
        Assert.Equal(11, model[1].Id);
        Assert.Null(model[1].Name);

        Assert.Equal(4, modelState.Count);
        Assert.Equal(2, modelState.ErrorCount);
        Assert.False(modelState.IsValid);

        var entry = Assert.Single(modelState, kvp => kvp.Key == "[0].Id").Value;
        Assert.Equal("10", entry.AttemptedValue);
        Assert.Equal("10", entry.RawValue);

        entry = Assert.Single(modelState, kvp => kvp.Key == "[1].Id").Value;
        Assert.Equal("11", entry.AttemptedValue);
        Assert.Equal("11", entry.RawValue);

        entry = Assert.Single(modelState, kvp => kvp.Key == "[0].Name").Value;
        Assert.Null(entry.RawValue);
        Assert.Equal(ModelValidationState.Invalid, entry.ValidationState);

        entry = Assert.Single(modelState, kvp => kvp.Key == "[1].Name").Value;
        Assert.Null(entry.RawValue);
        Assert.Equal(ModelValidationState.Invalid, entry.ValidationState);
    }

    [Fact]
    public async Task CollectionModelBinder_BindsListOfSimpleType_WithIndex_Success()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(List<int>)
        };

        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString =
                new QueryString("?parameter.index=low&parameter.index=high&parameter[low]=10&parameter[high]=11");
        });

        var modelState = testContext.ModelState;

        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelBindingResult.IsModelSet);

        var model = Assert.IsType<List<int>>(modelBindingResult.Model);
        Assert.Equal(new List<int>() { 10, 11 }, model);

        // "index" is not stored in ModelState.
        Assert.Equal(2, modelState.Count);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);

        var entry = Assert.Single(modelState, kvp => kvp.Key == "parameter[low]").Value;
        Assert.Equal("10", entry.AttemptedValue);
        Assert.Equal("10", entry.RawValue);
        Assert.Equal(ModelValidationState.Valid, entry.ValidationState);

        entry = Assert.Single(modelState, kvp => kvp.Key == "parameter[high]").Value;
        Assert.Equal("11", entry.AttemptedValue);
        Assert.Equal("11", entry.RawValue);
        Assert.Equal(ModelValidationState.Valid, entry.ValidationState);
    }

    [Fact]
    public async Task CollectionModelBinder_BindsCollectionOfComplexType_WithRequiredProperty_WithIndex_PartialData()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(ICollection<Person2>)
        };

        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString("?index=low&index=high&[high].Id=11&[low].Id=10");
        });

        var modelState = testContext.ModelState;

        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelBindingResult.IsModelSet);

        var model = Assert.IsType<List<Person2>>(modelBindingResult.Model);
        Assert.Equal(10, model[0].Id);
        Assert.Null(model[0].Name);
        Assert.Equal(11, model[1].Id);
        Assert.Null(model[1].Name);

        Assert.Equal(4, modelState.Count);
        Assert.Equal(2, modelState.ErrorCount);
        Assert.False(modelState.IsValid);

        var entry = Assert.Single(modelState, kvp => kvp.Key == "[low].Id").Value;
        Assert.Equal("10", entry.AttemptedValue);
        Assert.Equal("10", entry.RawValue);

        entry = Assert.Single(modelState, kvp => kvp.Key == "[high].Id").Value;
        Assert.Equal("11", entry.AttemptedValue);
        Assert.Equal("11", entry.RawValue);

        entry = Assert.Single(modelState, kvp => kvp.Key == "[low].Name").Value;
        Assert.Null(entry.RawValue);
        Assert.Equal(ModelValidationState.Invalid, entry.ValidationState);

        entry = Assert.Single(modelState, kvp => kvp.Key == "[high].Name").Value;
        Assert.Null(entry.RawValue);
        Assert.Equal(ModelValidationState.Invalid, entry.ValidationState);
    }

    [Fact]
    public async Task CollectionModelBinder_BindsListOfComplexType_WithRequiredProperty_NoData()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(List<Person2>)
        };

        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);
        Assert.Empty(Assert.IsType<List<Person2>>(modelBindingResult.Model));

        Assert.Empty(modelState);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
    }

    private class Person4
    {
        public IList<Address4> Addresses { get; set; }
    }

    private class Address4
    {
        public int Zip { get; set; }

        public string Street { get; set; }
    }

    [Fact]
    public async Task CollectionModelBinder_UsesCustomIndexes()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(Person4)
        };

        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            var formCollection = new FormCollection(new Dictionary<string, StringValues>()
            {
                    { "Addresses.index", new [] { "Key1", "Key2" } },
                    { "Addresses[Key1].Street", new [] { "Street1" } },
                    { "Addresses[Key2].Street", new [] { "Street2" } },
            });

            request.Form = formCollection;
            request.ContentType = "application/x-www-form-urlencoded";
        });

        var modelState = testContext.ModelState;

        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelBindingResult.IsModelSet);
        Assert.IsType<Person4>(modelBindingResult.Model);

        Assert.Equal(2, modelState.Count);
        Assert.Equal(0, modelState.ErrorCount);
        Assert.True(modelState.IsValid);
        var entry = Assert.Single(modelState, kvp => kvp.Key == "Addresses[Key1].Street").Value;
        Assert.Equal("Street1", entry.AttemptedValue);
        Assert.Equal("Street1", entry.RawValue);

        entry = Assert.Single(modelState, kvp => kvp.Key == "Addresses[Key2].Street").Value;
        Assert.Equal("Street2", entry.AttemptedValue);
        Assert.Equal("Street2", entry.RawValue);
    }

    private class Person5
    {
        public IList<Address5> Addresses { get; set; }
    }

    private class Address5
    {
        public int Zip { get; set; }

        [StringLength(3)]
        public string Street { get; set; }
    }

    [Fact]
    public async Task CollectionModelBinder_UsesCustomIndexes_AddsErrorsWithCorrectKeys()
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(Person5)
        };

        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            var formCollection = new FormCollection(new Dictionary<string, StringValues>()
            {
                    { "Addresses.index", new [] { "Key1" } },
                    { "Addresses[Key1].Street", new [] { "Street1" } },
            });

            request.Form = formCollection;
            request.ContentType = "application/x-www-form-urlencoded";
        });

        var modelState = testContext.ModelState;

        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelBindingResult.IsModelSet);
        Assert.IsType<Person5>(modelBindingResult.Model);

        Assert.False(modelState.IsValid);

        var kvp = Assert.Single(modelState);
        Assert.Equal("Addresses[Key1].Street", kvp.Key);
        var entry = kvp.Value;
        var error = Assert.Single(entry.Errors);
        Assert.Equal(ValidationAttributeUtil.GetStringLengthErrorMessage(null, 3, "Street"), error.ErrorMessage);
    }

    [Theory]
    [InlineData("?[0].Street=LongStreet")]
    [InlineData("?index=low&[low].Street=LongStreet")]
    [InlineData("?parameter[0].Street=LongStreet")]
    [InlineData("?parameter.index=low&parameter[low].Street=LongStreet")]
    [InlineData("?parameter.index=index&parameter[index].Street=LongStreet")]
    public async Task CollectionModelBinder_BindsCollectionOfComplexType_ImpliedPrefix_FindsValidationErrors(
        string queryString)
    {
        // Arrange
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(ICollection<Address5>),
        };

        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.QueryString = new QueryString(queryString);
        });

        var modelState = testContext.ModelState;

        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelBindingResult.IsModelSet);
        var model = Assert.IsType<List<Address5>>(modelBindingResult.Model);
        var address = Assert.Single(model);
        Assert.Equal("LongStreet", address.Street);

        Assert.False(modelState.IsValid);

        var entry = Assert.Single(modelState).Value;
        var error = Assert.Single(entry.Errors);
        Assert.Equal(ValidationAttributeUtil.GetStringLengthErrorMessage(null, 3, "Street"), error.ErrorMessage);
    }

    // parameter type, form content, expected type
    public static TheoryData<Type, IDictionary<string, StringValues>, Type> CollectionTypeData
    {
        get
        {
            return new TheoryData<Type, IDictionary<string, StringValues>, Type>
                {
                    {
                        typeof(IEnumerable<string>),
                        new Dictionary<string, StringValues>
                        {
                            { "[0]", new[] { "hello" } },
                            { "[1]", new[] { "world" } },
                        },
                        typeof(List<string>)
                    },
                    {
                        typeof(ICollection<string>),
                        new Dictionary<string, StringValues>
                        {
                            { "index", new[] { "low", "high" } },
                            { "[low]", new[] { "hello" } },
                            { "[high]", new[] { "world" } },
                        },
                        typeof(List<string>)
                    },
                    {
                        typeof(IReadOnlyCollection<string>),
                        new Dictionary<string, StringValues>
                        {
                            { "index", new[] { "low", "high" } },
                            { "[low]", new[] { "hello" } },
                            { "[high]", new[] { "world" } },
                        },
                        typeof(List<string>)
                    },
                    {
                        typeof(IList<string>),
                        new Dictionary<string, StringValues>
                        {
                            { "[0]", new[] { "hello" } },
                            { "[1]", new[] { "world" } },
                        },
                        typeof(List<string>)
                    },
                    {
                        typeof(IReadOnlyList<string>),
                        new Dictionary<string, StringValues>
                        {
                            { "[0]", new[] { "hello" } },
                            { "[1]", new[] { "world" } },
                        },
                        typeof(List<string>)
                    },
                    {
                        typeof(List<string>),
                        new Dictionary<string, StringValues>
                        {
                            { "index", new[] { "low", "high" } },
                            { "[low]", new[] { "hello" } },
                            { "[high]", new[] { "world" } },
                        },
                        typeof(List<string>)
                    },
                    {
                        typeof(ClosedGenericCollection),
                        new Dictionary<string, StringValues>
                        {
                            { "[0]", new[] { "hello" } },
                            { "[1]", new[] { "world" } },
                        },
                        typeof(ClosedGenericCollection)
                    },
                    {
                        typeof(ClosedGenericList),
                        new Dictionary<string, StringValues>
                        {
                            { "index", new[] { "low", "high" } },
                            { "[low]", new[] { "hello" } },
                            { "[high]", new[] { "world" } },
                        },
                        typeof(ClosedGenericList)
                    },
                    {
                        typeof(ExplicitClosedGenericCollection),
                        new Dictionary<string, StringValues>
                        {
                            { "[0]", new[] { "hello" } },
                            { "[1]", new[] { "world" } },
                        },
                        typeof(ExplicitClosedGenericCollection)
                    },
                    {
                        typeof(ExplicitClosedGenericList),
                        new Dictionary<string, StringValues>
                        {
                            { "index", new[] { "low", "high" } },
                            { "[low]", new[] { "hello" } },
                            { "[high]", new[] { "world" } },
                        },
                        typeof(ExplicitClosedGenericList)
                    },
                    {
                        typeof(ExplicitCollection<string>),
                        new Dictionary<string, StringValues>
                        {
                            { "[0]", new[] { "hello" } },
                            { "[1]", new[] { "world" } },
                        },
                        typeof(ExplicitCollection<string>)
                    },
                    {
                        typeof(ExplicitList<string>),
                        new Dictionary<string, StringValues>
                        {
                            { "index", new[] { "low", "high" } },
                            { "[low]", new[] { "hello" } },
                            { "[high]", new[] { "world" } },
                        },
                        typeof(ExplicitList<string>)
                    },
                    {
                        typeof(IEnumerable<string>),
                        new Dictionary<string, StringValues>
                        {
                            { string.Empty, new[] { "hello", "world" } },
                        },
                        typeof(List<string>)
                    },
                    {
                        typeof(ICollection<string>),
                        new Dictionary<string, StringValues>
                        {
                            { "[]", new[] { "hello", "world" } },
                        },
                        typeof(List<string>)
                    },
                    {
                        typeof(IList<string>),
                        new Dictionary<string, StringValues>
                        {
                            { string.Empty, new[] { "hello", "world" } },
                        },
                        typeof(List<string>)
                    },
                    {
                        typeof(List<string>),
                        new Dictionary<string, StringValues>
                        {
                            { "[]", new[] { "hello", "world" } },
                        },
                        typeof(List<string>)
                    },
                    {
                        typeof(ClosedGenericCollection),
                        new Dictionary<string, StringValues>
                        {
                            { string.Empty, new[] { "hello", "world" } },
                        },
                        typeof(ClosedGenericCollection)
                    },
                    {
                        typeof(ClosedGenericList),
                        new Dictionary<string, StringValues>
                        {
                            { "[]", new[] { "hello", "world" } },
                        },
                        typeof(ClosedGenericList)
                    },
                    {
                        typeof(ExplicitClosedGenericCollection),
                        new Dictionary<string, StringValues>
                        {
                            { string.Empty, new[] { "hello", "world" } },
                        },
                        typeof(ExplicitClosedGenericCollection)
                    },
                    {
                        typeof(ExplicitClosedGenericList),
                        new Dictionary<string, StringValues>
                        {
                            { "[]", new[] { "hello", "world" } },
                        },
                        typeof(ExplicitClosedGenericList)
                    },
                    {
                        typeof(ExplicitCollection<string>),
                        new Dictionary<string, StringValues>
                        {
                            { string.Empty, new[] { "hello", "world" } },
                        },
                        typeof(ExplicitCollection<string>)
                    },
                    {
                        typeof(ExplicitList<string>),
                        new Dictionary<string, StringValues>
                        {
                            { "[]", new[] { "hello", "world" } },
                        },
                        typeof(ExplicitList<string>)
                    },
                };
        }
    }

    [Theory]
    [MemberData(nameof(CollectionTypeData))]
    public async Task CollectionModelBinder_BindsParameterToExpectedType(
        Type parameterType,
        Dictionary<string, StringValues> formContent,
        Type expectedType)
    {
        // Arrange
        var expectedCollection = new List<string> { "hello", "world" };
        var parameter = new ParameterDescriptor
        {
            Name = "parameter",
            ParameterType = parameterType,
        };

        var parameterBinder = ModelBindingTestHelper.GetParameterBinder();
        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            request.Form = new FormCollection(formContent);
        });
        var modelState = testContext.ModelState;

        // Act
        var modelBindingResult = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelBindingResult.IsModelSet);

        Assert.IsType(expectedType, modelBindingResult.Model);

        var model = modelBindingResult.Model as IEnumerable<string>;
        Assert.NotNull(model); // Guard
        Assert.Equal(expectedCollection, model);

        Assert.True(modelState.IsValid);
        Assert.NotEmpty(modelState);
        Assert.Equal(0, modelState.ErrorCount);
    }

    // Regression test for #7052
    [Fact]
    public async Task CollectionModelBinder_ThrowsOn1025Items_AtTopLevel()
    {
        // Arrange
        var expectedMessage = $"Collection bound to 'parameter' exceeded " +
            $"{nameof(MvcOptions)}.{nameof(MvcOptions.MaxModelBindingCollectionSize)} (1024). This limit is a " +
            $"safeguard against incorrect model binders and models. Address issues in " +
            $"'{typeof(SuccessfulModel)}'. For example, this type may have a property with a model binder that " +
            $"always succeeds. See the {nameof(MvcOptions)}.{nameof(MvcOptions.MaxModelBindingCollectionSize)} " +
            $"documentation for more information.";
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(IList<SuccessfulModel>),
        };

        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            // CollectionModelBinder binds an empty collection when value providers are all empty.
            request.QueryString = new QueryString("?a=b");
        });

        var modelState = testContext.ModelState;
        var metadata = testContext.MetadataProvider.GetMetadataForType(parameter.ParameterType);
        var valueProvider = await CompositeValueProvider.CreateAsync(testContext);
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder(testContext);

        // Act & Assert
        var exception = await Assert.ThrowsAsync<InvalidOperationException>(
            () => parameterBinder.BindModelAsync(parameter, testContext));
        Assert.Equal(expectedMessage, exception.Message);
    }

    // Ensure CollectionModelBinder allows MaxModelBindingCollectionSize items.
    [Fact]
    public async Task CollectionModelBinder_Binds3Items_WithIndices()
    {
        // Arrange
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(IList<SuccessfulModel>),
        };

        var testContext = ModelBindingTestHelper.GetTestContext(
            request =>
            {
                request.QueryString = new QueryString("?Index=0&Index=1&Index=2");
            },
            options => options.MaxModelBindingCollectionSize = 3);

        var modelState = testContext.ModelState;
        var metadata = testContext.MetadataProvider.GetMetadataForType(parameter.ParameterType);
        var valueProvider = await CompositeValueProvider.CreateAsync(testContext);
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder(testContext);

        // Act
        var result = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelState.IsValid);
        Assert.Equal(0, modelState.ErrorCount);

        Assert.True(result.IsModelSet);
        var locations = Assert.IsType<List<SuccessfulModel>>(result.Model);
        Assert.Collection(
            locations,
            item =>
            {
                Assert.True(item.IsBound);
                Assert.Null(item.Name);
            },
            item =>
            {
                Assert.True(item.IsBound);
                Assert.Null(item.Name);
            },
            item =>
            {
                Assert.True(item.IsBound);
                Assert.Null(item.Name);
            });
    }

    // Ensure CollectionModelBinder disallows one more than MaxModelBindingCollectionSize items.
    [Fact]
    public async Task CollectionModelBinder_ThrowsOn4Items_WithIndices()
    {
        // Arrange
        var expectedMessage = $"Collection bound to 'parameter' exceeded " +
            $"{nameof(MvcOptions)}.{nameof(MvcOptions.MaxModelBindingCollectionSize)} (3). This limit is a " +
            $"safeguard against incorrect model binders and models. Address issues in " +
            $"'{typeof(SuccessfulModel)}'. For example, this type may have a property with a model binder that " +
            $"always succeeds. See the {nameof(MvcOptions)}.{nameof(MvcOptions.MaxModelBindingCollectionSize)} " +
            $"documentation for more information.";
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(IList<SuccessfulModel>),
        };

        var testContext = ModelBindingTestHelper.GetTestContext(
            request =>
            {
                request.QueryString = new QueryString("?Index=0&Index=1&Index=2&Index=3");
            },
            options => options.MaxModelBindingCollectionSize = 3);

        var modelState = testContext.ModelState;
        var metadata = testContext.MetadataProvider.GetMetadataForType(parameter.ParameterType);
        var valueProvider = await CompositeValueProvider.CreateAsync(testContext);
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder(testContext);

        // Act & Assert
        var exception = await Assert.ThrowsAsync<InvalidOperationException>(
            () => parameterBinder.BindModelAsync(parameter, testContext));
        Assert.Equal(expectedMessage, exception.Message);
    }

    private class SuccessfulContainer
    {
        public IList<SuccessfulModel> Successes { get; set; }
    }

    [Fact]
    public async Task CollectionModelBinder_ThrowsOn1025Items()
    {
        // Arrange
        var expectedMessage = $"Collection bound to 'Successes' exceeded " +
            $"{nameof(MvcOptions)}.{nameof(MvcOptions.MaxModelBindingCollectionSize)} (1024). This limit is a " +
            $"safeguard against incorrect model binders and models. Address issues in " +
            $"'{typeof(SuccessfulModel)}'. For example, this type may have a property with a model binder that " +
            $"always succeeds. See the {nameof(MvcOptions)}.{nameof(MvcOptions.MaxModelBindingCollectionSize)} " +
            $"documentation for more information.";
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(SuccessfulContainer),
        };

        var testContext = ModelBindingTestHelper.GetTestContext(request =>
        {
            // CollectionModelBinder binds an empty collection when value providers lack matching data.
            request.QueryString = new QueryString("?Successes[0]=b");
        });

        var modelState = testContext.ModelState;
        var metadata = testContext.MetadataProvider.GetMetadataForType(parameter.ParameterType);
        var valueProvider = await CompositeValueProvider.CreateAsync(testContext);
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder(testContext);

        // Act & Assert
        var exception = await Assert.ThrowsAsync<InvalidOperationException>(
            () => parameterBinder.BindModelAsync(parameter, testContext));
        Assert.Equal(expectedMessage, exception.Message);
    }

    [Fact]
    public async Task CollectionModelBinder_CollectionOfSimpleTypes_DoesNotResultInValidationError()
    {
        // Regression test for https://github.com/dotnet/aspnetcore/issues/13512
        // Arrange
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(Collection<string>),
        };

        var testContext = ModelBindingTestHelper.GetTestContext(
            request =>
            {
                request.QueryString = new QueryString("?[0]=hello&[1]=");
            });

        var modelState = testContext.ModelState;
        var metadata = testContext.MetadataProvider.GetMetadataForType(parameter.ParameterType);
        var valueProvider = await CompositeValueProvider.CreateAsync(testContext);
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder(testContext);

        // Act
        var result = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelState.IsValid);
        Assert.Equal(0, modelState.ErrorCount);

        Assert.True(result.IsModelSet);
        var model = Assert.IsType<Collection<string>>(result.Model);
        Assert.Collection(
            model,
            item => Assert.Equal("hello", item),
            item => Assert.Null(item));

        Assert.Collection(
            modelState,
            kvp =>
            {
                Assert.Equal("[0]", kvp.Key);
                Assert.Equal(ModelValidationState.Valid, kvp.Value.ValidationState);
            },
            kvp =>
            {
                Assert.Equal("[1]", kvp.Key);
                Assert.Equal(ModelValidationState.Valid, kvp.Value.ValidationState);
            });
    }

    [Fact]
    public async Task CollectionModelBinder_CollectionOfNonNullableTypes_AppliesImplicitRequired()
    {
        // Arrange
        var parameter = new ParameterDescriptor()
        {
            Name = "parameter",
            ParameterType = typeof(Collection<string>),
        };

        var testContext = ModelBindingTestHelper.GetTestContext(
            request =>
            {
                request.QueryString = new QueryString("?[0]=hello&[1]=");
            });

        var modelState = testContext.ModelState;
        var metadata = testContext.MetadataProvider.GetMetadataForType(parameter.ParameterType);
        var valueProvider = await CompositeValueProvider.CreateAsync(testContext);
        var parameterBinder = ModelBindingTestHelper.GetParameterBinder(testContext);

        // Act
        var result = await parameterBinder.BindModelAsync(parameter, testContext);

        // Assert
        Assert.True(modelState.IsValid);
        Assert.Equal(0, modelState.ErrorCount);

        Assert.True(result.IsModelSet);
        var model = Assert.IsType<Collection<string>>(result.Model);
        Assert.Collection(
            model,
            item => Assert.Equal("hello", item),
            item => Assert.Null(item));

        Assert.Collection(
            modelState,
            kvp =>
            {
                Assert.Equal("[0]", kvp.Key);
                Assert.Equal(ModelValidationState.Valid, kvp.Value.ValidationState);
            },
            kvp =>
            {
                Assert.Equal("[1]", kvp.Key);
                Assert.Equal(ModelValidationState.Valid, kvp.Value.ValidationState);
            });
    }

    private class ClosedGenericCollection : Collection<string>
    {
    }

    private class ClosedGenericList : List<string>
    {
    }

    private class ExplicitClosedGenericCollection : ICollection<string>
    {
        private readonly List<string> _data = new List<string>();

        int ICollection<string>.Count
        {
            get
            {
                throw new NotImplementedException();
            }
        }

        bool ICollection<string>.IsReadOnly
        {
            get
            {
                return false;
            }
        }

        void ICollection<string>.Add(string item)
        {
            _data.Add(item);
        }

        void ICollection<string>.Clear()
        {
            _data.Clear();
        }

        bool ICollection<string>.Contains(string item)
        {
            throw new NotImplementedException();
        }

        void ICollection<string>.CopyTo(string[] array, int arrayIndex)
        {
            throw new NotImplementedException();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return ((IEnumerable)_data).GetEnumerator();
        }

        IEnumerator<string> IEnumerable<string>.GetEnumerator()
        {
            return _data.GetEnumerator();
        }

        bool ICollection<string>.Remove(string item)
        {
            throw new NotImplementedException();
        }
    }

    private class ExplicitClosedGenericList : IList<string>
    {
        private readonly List<string> _data = new List<string>();

        string IList<string>.this[int index]
        {
            get
            {
                throw new NotImplementedException();
            }

            set
            {
                throw new NotImplementedException();
            }
        }

        int ICollection<string>.Count
        {
            get
            {
                throw new NotImplementedException();
            }
        }

        bool ICollection<string>.IsReadOnly
        {
            get
            {
                return false;
            }
        }

        void ICollection<string>.Add(string item)
        {
            _data.Add(item);
        }

        void ICollection<string>.Clear()
        {
            _data.Clear();
        }

        bool ICollection<string>.Contains(string item)
        {
            throw new NotImplementedException();
        }

        void ICollection<string>.CopyTo(string[] array, int arrayIndex)
        {
            throw new NotImplementedException();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return ((IEnumerable)_data).GetEnumerator();
        }

        IEnumerator<string> IEnumerable<string>.GetEnumerator()
        {
            return _data.GetEnumerator();
        }

        int IList<string>.IndexOf(string item)
        {
            throw new NotImplementedException();
        }

        void IList<string>.Insert(int index, string item)
        {
            throw new NotImplementedException();
        }

        bool ICollection<string>.Remove(string item)
        {
            throw new NotImplementedException();
        }

        void IList<string>.RemoveAt(int index)
        {
            throw new NotImplementedException();
        }
    }

    private class ExplicitCollection<T> : ICollection<T>
    {
        private readonly List<T> _data = new List<T>();

        int ICollection<T>.Count
        {
            get
            {
                throw new NotImplementedException();
            }
        }

        bool ICollection<T>.IsReadOnly
        {
            get
            {
                return false;
            }
        }

        void ICollection<T>.Add(T item)
        {
            _data.Add(item);
        }

        void ICollection<T>.Clear()
        {
            _data.Clear();
        }

        bool ICollection<T>.Contains(T item)
        {
            throw new NotImplementedException();
        }

        void ICollection<T>.CopyTo(T[] array, int arrayIndex)
        {
            throw new NotImplementedException();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return ((IEnumerable)_data).GetEnumerator();
        }

        IEnumerator<T> IEnumerable<T>.GetEnumerator()
        {
            return _data.GetEnumerator();
        }

        bool ICollection<T>.Remove(T item)
        {
            throw new NotImplementedException();
        }
    }

    private class ExplicitList<T> : IList<T>
    {
        private readonly List<T> _data = new List<T>();

        T IList<T>.this[int index]
        {
            get
            {
                throw new NotImplementedException();
            }

            set
            {
                throw new NotImplementedException();
            }
        }

        int ICollection<T>.Count
        {
            get
            {
                throw new NotImplementedException();
            }
        }

        bool ICollection<T>.IsReadOnly
        {
            get
            {
                return false;
            }
        }

        void ICollection<T>.Add(T item)
        {
            _data.Add(item);
        }

        void ICollection<T>.Clear()
        {
            _data.Clear();
        }

        bool ICollection<T>.Contains(T item)
        {
            throw new NotImplementedException();
        }

        void ICollection<T>.CopyTo(T[] array, int arrayIndex)
        {
            throw new NotImplementedException();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return ((IEnumerable)_data).GetEnumerator();
        }

        IEnumerator<T> IEnumerable<T>.GetEnumerator()
        {
            return _data.GetEnumerator();
        }

        int IList<T>.IndexOf(T item)
        {
            throw new NotImplementedException();
        }

        void IList<T>.Insert(int index, T item)
        {
            throw new NotImplementedException();
        }

        bool ICollection<T>.Remove(T item)
        {
            throw new NotImplementedException();
        }

        void IList<T>.RemoveAt(int index)
        {
            throw new NotImplementedException();
        }
    }
}
