// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System.Collections.Generic;
using System.IO;
using Microsoft.AspNetCore.Html;
using Microsoft.AspNetCore.Mvc.ViewFeatures;
using Moq;
using Xunit;

namespace Microsoft.AspNetCore.Mvc.Rendering
{
    /// <summary>
    /// Tests the <see cref="IHtmlHelper"/>'s <see cref="IHtmlHelper.BeginForm"/> and
    /// <see cref="IHtmlHelper.BeginRouteForm"/> methods.
    /// </summary>
    public class HtmlHelperFormExtensionsTest
    {
        private static readonly IEnumerable<string> _actionNames = new List<string> { null, "Details" };
        private static readonly IEnumerable<string> _controllerNames = new List<string> { null, "Product" };
        private static readonly IEnumerable<object> _htmlAttributes = new List<object>
        {
            null,
            new { isprint = "false", showreviews = "false" },
            new Dictionary<string, object> { { "isprint", "false" }, { "showreviews", "true" }, },
        };
        private static readonly IEnumerable<FormMethod> _methods = new List<FormMethod>
        {
            FormMethod.Get,
            FormMethod.Post,
        };
        private static readonly IEnumerable<string> _routeNames = new List<string> { null, "default" };
        private static readonly IEnumerable<object> _routeValues = new List<object>
        {
            null,
            new { p1_name = "p1-value" },
            new Dictionary<string, object> { { "p1-name", "p1-value" }, { "p2-name", "p2-value" } },
        };

        public static TheoryData<string, string> ActionNameAndControllerNameDataSet
        {
            get
            {
                var dataSet = new TheoryData<string, string>();
                foreach (var actionName in _actionNames)
                {
                    foreach (var controllerName in _controllerNames)
                    {
                        dataSet.Add(actionName, controllerName);
                    }
                }

                return dataSet;
            }
        }

        public static TheoryData<string, string, FormMethod> ActionNameControllerNameAndMethodDataSet
        {
            get
            {
                var dataSet = new TheoryData<string, string, FormMethod>();
                foreach (var actionName in _actionNames)
                {
                    foreach (var controllerName in _controllerNames)
                    {
                        foreach (var method in _methods)
                        {
                            dataSet.Add(actionName, controllerName, method);
                        }
                    }
                }

                return dataSet;
            }
        }

        public static TheoryData<string, string, FormMethod, object> ActionNameControllerNameMethodAndHtmlAttributesDataSet
        {
            get
            {
                var dataSet = new TheoryData<string, string, FormMethod, object>();
                foreach (var actionName in _actionNames)
                {
                    foreach (var controllerName in _controllerNames)
                    {
                        foreach (var method in _methods)
                        {
                            foreach (var htmlAttributes in _htmlAttributes)
                            {
                                dataSet.Add(actionName, controllerName, method, htmlAttributes);
                            }
                        }
                    }
                }

                return dataSet;
            }
        }

        public static TheoryData<string, string, object> ActionNameControllerNameAndRouteValuesDataSet
        {
            get
            {
                var dataSet = new TheoryData<string, string, object>();
                foreach (var actionName in _actionNames)
                {
                    foreach (var controllerName in _controllerNames)
                    {
                        foreach (var routeValues in _routeValues)
                        {
                            dataSet.Add(actionName, controllerName, routeValues);
                        }
                    }
                }

                return dataSet;
            }
        }

        public static TheoryData<string, string, object, FormMethod> ActionNameControllerNameRouteValuesAndMethodDataSet
        {
            get
            {
                var dataSet = new TheoryData<string, string, object, FormMethod>();
                foreach (var actionName in _actionNames)
                {
                    foreach (var controllerName in _controllerNames)
                    {
                        foreach (var routeValues in _routeValues)
                        {
                            foreach (var method in _methods)
                            {
                                dataSet.Add(actionName, controllerName, routeValues, method);
                            }
                        }
                    }
                }

                return dataSet;
            }
        }

        public static TheoryData<FormMethod> MethodDataSet
        {
            get
            {
                var dataSet = new TheoryData<FormMethod>();
                foreach (var method in _methods)
                {
                    dataSet.Add(method);
                }

                return dataSet;
            }
        }

        public static TheoryData<FormMethod, object> MethodAndHtmlAttributesDataSet
        {
            get
            {
                var dataSet = new TheoryData<FormMethod, object>();
                foreach (var method in _methods)
                {
                    foreach (var htmlAttributes in _htmlAttributes)
                    {
                        dataSet.Add(method, htmlAttributes);
                    }
                }

                return dataSet;
            }
        }

        public static TheoryData<string> RouteNameDataSet
        {
            get
            {
                var dataSet = new TheoryData<string>();
                foreach (var routeName in _routeNames)
                {
                    dataSet.Add(routeName);
                }

                return dataSet;
            }
        }

        public static TheoryData<string, FormMethod> RouteNameAndMethodDataSet
        {
            get
            {
                var dataSet = new TheoryData<string, FormMethod>();
                foreach (var routeName in _routeNames)
                {
                    foreach (var method in _methods)
                    {
                        dataSet.Add(routeName, method);
                    }
                }

                return dataSet;
            }
        }

        public static TheoryData<string, FormMethod, object> RouteNameMethodAndHtmlAttributesDataSet
        {
            get
            {
                var dataSet = new TheoryData<string, FormMethod, object>();
                foreach (var routeName in _routeNames)
                {
                    foreach (var method in _methods)
                    {
                        foreach (var htmlAttributes in _htmlAttributes)
                        {
                            dataSet.Add(routeName, method, htmlAttributes);
                        }
                    }
                }

                return dataSet;
            }
        }

        public static TheoryData<string, object> RouteNameAndRouteValuesDataSet
        {
            get
            {
                var dataSet = new TheoryData<string, object>();
                foreach (var routeName in _routeNames)
                {
                    foreach (var routeValues in _routeValues)
                    {
                        dataSet.Add(routeName, routeValues);
                    }
                }

                return dataSet;
            }
        }

        public static TheoryData<string, object, FormMethod> RouteNameRouteValuesAndMethodDataSet
        {
            get
            {
                var dataSet = new TheoryData<string, object, FormMethod>();
                foreach (var routeName in _routeNames)
                {
                    foreach (var routeValues in _routeValues)
                    {
                        foreach (var method in _methods)
                        {
                            dataSet.Add(routeName, routeValues, method);
                        }
                    }
                }

                return dataSet;
            }
        }

        public static TheoryData<object> RouteValuesDataSet
        {
            get
            {
                var dataSet = new TheoryData<object>();
                foreach (var routeValues in _routeValues)
                {
                    dataSet.Add(routeValues);
                }

                return dataSet;
            }
        }

        [Fact]
        public void BeginFormWithNoParameters_CallsHtmlGeneratorWithExpectedValues()
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateForm(
                    htmlHelper.ViewContext,
                    null,   // actionName
                    null,   // controllerName
                    null,   // routeValues
                    "post", // method
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();
            htmlGenerator
                .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                .Returns(HtmlString.Empty)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginForm();

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Fact]
        public void BeginForm_WithAntiforgery_CallsHtmlGeneratorWithExpectedValues()
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateForm(
                    htmlHelper.ViewContext,
                    null,   // actionName
                    null,   // controllerName
                    null,   // routeValues
                    "post", // method
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();
            htmlGenerator
                .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                .Returns(HtmlString.Empty)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginForm(antiforgery: true);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Fact]
        public void BeginForm_SuppressAntiforgery_CallsHtmlGeneratorWithExpectedValues()
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateForm(
                    htmlHelper.ViewContext,
                    null,   // actionName
                    null,   // controllerName
                    null,   // routeValues
                    "post", // method
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginForm(antiforgery: false);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(MethodDataSet))]
        public void BeginFormWithMethodParameter_CallsHtmlGeneratorWithExpectedValues(FormMethod method)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateForm(
                    htmlHelper.ViewContext,
                    null,   // actionName
                    null,   // controllerName
                    null,   // routeValues
                    method.ToString().ToLowerInvariant(),
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();

            if (method != FormMethod.Get)
            {
                htmlGenerator
                    .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                    .Returns(HtmlString.Empty)
                    .Verifiable();
            }

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginForm(method);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(MethodAndHtmlAttributesDataSet))]
        public void BeginFormWithMethodAndHtmlAttributesParameters_CallsHtmlGeneratorWithExpectedValues(
            FormMethod method,
            object htmlAttributes)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateForm(
                    htmlHelper.ViewContext,
                    null,   // actionName
                    null,   // controllerName
                    null,   // routeValues
                    method.ToString().ToLowerInvariant(),
                    htmlAttributes))
                .Returns(tagBuilder)
                .Verifiable();

            if (method != FormMethod.Get)
            {
                htmlGenerator
                    .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                    .Returns(HtmlString.Empty)
                    .Verifiable();
            }

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginForm(method, htmlAttributes);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(MethodAndHtmlAttributesDataSet))]
        public void BeginFormWithMethodAndHtmlAttributesParameters_WithAntiforgery_CallsHtmlGeneratorWithExpectedValues(
            FormMethod method,
            object htmlAttributes)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateForm(
                    htmlHelper.ViewContext,
                    null,   // actionName
                    null,   // controllerName
                    null,   // routeValues
                    method.ToString().ToLowerInvariant(),
                    htmlAttributes))
                .Returns(tagBuilder)
                .Verifiable();
            htmlGenerator
                .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                .Returns(HtmlString.Empty)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginForm(method, antiforgery: true, htmlAttributes: htmlAttributes);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(MethodAndHtmlAttributesDataSet))]
        public void BeginFormWithMethodAndHtmlAttributesParameters_SuppressAntiforgery_CallsHtmlGeneratorWithExpectedValues(
            FormMethod method,
            object htmlAttributes)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateForm(
                    htmlHelper.ViewContext,
                    null,   // actionName
                    null,   // controllerName
                    null,   // routeValues
                    method.ToString().ToLowerInvariant(),
                    htmlAttributes))
                .Returns(tagBuilder)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginForm(method, antiforgery: false, htmlAttributes: htmlAttributes);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(RouteValuesDataSet))]
        public void BeginFormWithRouteValuesParameter_CallsHtmlGeneratorWithExpectedValues(object routeValues)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateForm(
                    htmlHelper.ViewContext,
                    null,   // actionName
                    null,   // controllerName
                    routeValues,
                    "post", // method
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();
            htmlGenerator
                .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                .Returns(HtmlString.Empty)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginForm(routeValues);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(ActionNameAndControllerNameDataSet))]
        public void BeginFormWithActionNameAndControllerNameParameters_CallsHtmlGeneratorWithExpectedValues(
            string actionName,
            string controllerName)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateForm(
                    htmlHelper.ViewContext,
                    actionName,
                    controllerName,
                    null,   // routeValues
                    "post", // method
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();
            htmlGenerator
                .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                .Returns(HtmlString.Empty)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginForm(actionName, controllerName);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(ActionNameControllerNameAndRouteValuesDataSet))]
        public void BeginFormWithActionNameControllerNameAndRouteValuesParameters_CallsHtmlGeneratorWithExpectedValues(
            string actionName,
            string controllerName,
            object routeValues)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateForm(
                    htmlHelper.ViewContext,
                    actionName,
                    controllerName,
                    routeValues,
                    "post", // method
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();
            htmlGenerator
                .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                .Returns(HtmlString.Empty)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginForm(actionName, controllerName, routeValues);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(ActionNameControllerNameAndMethodDataSet))]
        public void BeginFormWithActionNameControllerNameAndMethodParameters_CallsHtmlGeneratorWithExpectedValues(
            string actionName,
            string controllerName,
            FormMethod method)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateForm(
                    htmlHelper.ViewContext,
                    actionName,
                    controllerName,
                    null,   // routeValues
                    method.ToString().ToLowerInvariant(),
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();

            if (method != FormMethod.Get)
            {
                htmlGenerator
                    .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                    .Returns(HtmlString.Empty)
                    .Verifiable();
            }

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginForm(actionName, controllerName, method);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(ActionNameControllerNameRouteValuesAndMethodDataSet))]
        public void BeginFormWithActionNameControllerNameRouteValuesAndMethodParameters_CallsHtmlGeneratorWithExpectedValues(
            string actionName,
            string controllerName,
            object routeValues,
            FormMethod method)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateForm(
                    htmlHelper.ViewContext,
                    actionName,
                    controllerName,
                    routeValues,
                    method.ToString().ToLowerInvariant(),
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();

            if (method != FormMethod.Get)
            {
                htmlGenerator
                .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                .Returns(HtmlString.Empty)
                .Verifiable();
            }

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginForm(actionName, controllerName, routeValues, method);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(ActionNameControllerNameMethodAndHtmlAttributesDataSet))]
        public void BeginFormWithActionNameControllerNameMethodAndHtmlAttributesParameters_CallsHtmlGeneratorWithExpectedValues(
            string actionName,
            string controllerName,
            FormMethod method,
            object htmlAttributes)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateForm(
                    htmlHelper.ViewContext,
                    actionName,
                    controllerName,
                    null,   // routeValues
                    method.ToString().ToLowerInvariant(),
                    htmlAttributes))
                .Returns(tagBuilder)
                .Verifiable();

            if (method != FormMethod.Get)
            {
                htmlGenerator
                    .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                    .Returns(HtmlString.Empty)
                    .Verifiable();
            }

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginForm(actionName, controllerName, method, htmlAttributes);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(ActionNameControllerNameMethodAndHtmlAttributesDataSet))]
        public void BeginFormWithActionNameControllerNameMethodAndHtmlAttributesParameters_WithAntiforgery_CallsHtmlGeneratorWithExpectedValues(
            string actionName,
            string controllerName,
            FormMethod method,
            object htmlAttributes)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateForm(
                    htmlHelper.ViewContext,
                    actionName,
                    controllerName,
                    null,   // routeValues
                    method.ToString().ToLowerInvariant(),
                    htmlAttributes))
                .Returns(tagBuilder)
                .Verifiable();
            htmlGenerator
                .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                .Returns(HtmlString.Empty)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginForm(
                actionName,
                controllerName,
                routeValues: null,
                method: method,
                antiforgery: true,
                htmlAttributes: htmlAttributes);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(ActionNameControllerNameMethodAndHtmlAttributesDataSet))]
        public void BeginFormWithActionNameControllerNameMethodAndHtmlAttributesParameters_SuppressAntiforgery_CallsHtmlGeneratorWithExpectedValues(
            string actionName,
            string controllerName,
            FormMethod method,
            object htmlAttributes)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateForm(
                    htmlHelper.ViewContext,
                    actionName,
                    controllerName,
                    null,   // routeValues
                    method.ToString().ToLowerInvariant(),
                    htmlAttributes))
                .Returns(tagBuilder)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginForm(
                actionName,
                controllerName,
                routeValues: null,
                method: method,
                antiforgery: false,
                htmlAttributes: htmlAttributes);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(RouteValuesDataSet))]
        public void BeginRouteFormWithRouteValuesParameter_CallsHtmlGeneratorWithExpectedValues(object routeValues)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateRouteForm(
                    htmlHelper.ViewContext,
                    null,   // routeName
                    routeValues,
                    "post", // method
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();
            htmlGenerator
                .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                .Returns(HtmlString.Empty)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginRouteForm(routeValues);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(RouteValuesDataSet))]
        public void BeginRouteFormWithRouteValuesParameter_WithAntiforgery_CallsHtmlGeneratorWithExpectedValues(
            object routeValues)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateRouteForm(
                    htmlHelper.ViewContext,
                    null,   // routeName
                    routeValues,
                    "post", // method
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();
            htmlGenerator
                .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                .Returns(HtmlString.Empty)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginRouteForm(routeValues, antiforgery: true);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(RouteValuesDataSet))]
        public void BeginRouteFormWithRouteValuesParameter_SuppressAntiforgery_CallsHtmlGeneratorWithExpectedValues(
            object routeValues)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateRouteForm(
                    htmlHelper.ViewContext,
                    null,   // routeName
                    routeValues,
                    "post", // method
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginRouteForm(routeValues, antiforgery: false);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(RouteNameDataSet))]
        public void BeginRouteFormWithRouteNameParameter_CallsHtmlGeneratorWithExpectedValues(string routeName)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateRouteForm(
                    htmlHelper.ViewContext,
                    routeName,
                    null,   // routeValues
                    "post", // method
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();
            htmlGenerator
                .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                .Returns(HtmlString.Empty)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginRouteForm(routeName);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(RouteNameDataSet))]
        public void BeginRouteFormWithRouteNameParameter_WithAntiforgery_CallsHtmlGeneratorWithExpectedValues(
            string routeName)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateRouteForm(
                    htmlHelper.ViewContext,
                    routeName,
                    null,   // routeValues
                    "post", // method
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();
            htmlGenerator
                .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                .Returns(HtmlString.Empty)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginRouteForm(routeName, antiforgery: true);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(RouteNameDataSet))]
        public void BeginRouteFormWithRouteNameParameter_SuppressAntiforgery_CallsHtmlGeneratorWithExpectedValues(
            string routeName)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateRouteForm(
                    htmlHelper.ViewContext,
                    routeName,
                    null,   // routeValues
                    "post", // method
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginRouteForm(routeName, antiforgery: false);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(RouteNameAndRouteValuesDataSet))]
        public void BeginRouteFormWithRouteNameAndRouteValuesParameters_CallsHtmlGeneratorWithExpectedValues(
            string routeName,
            object routeValues)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateRouteForm(
                    htmlHelper.ViewContext,
                    routeName,
                    routeValues,
                    "post", // method
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();
            htmlGenerator
                .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                .Returns(HtmlString.Empty)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginRouteForm(routeName, routeValues);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(RouteNameAndMethodDataSet))]
        public void BeginRouteFormWithRouteNameAndMethodParameters_CallsHtmlGeneratorWithExpectedValues(
            string routeName,
            FormMethod method)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateRouteForm(
                    htmlHelper.ViewContext,
                    routeName,
                    null,   // routeValues
                    method.ToString().ToLowerInvariant(),
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();

            if (method != FormMethod.Get)
            {
                htmlGenerator
                    .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                    .Returns(HtmlString.Empty)
                    .Verifiable();
            }

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginRouteForm(routeName, method);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(RouteNameRouteValuesAndMethodDataSet))]
        public void BeginRouteFormWithRouteNameRouteValuesAndMethodParameters_CallsHtmlGeneratorWithExpectedValues(
            string routeName,
            object routeValues,
            FormMethod method)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateRouteForm(
                    htmlHelper.ViewContext,
                    routeName,
                    routeValues,
                    method.ToString().ToLowerInvariant(),
                    null))  // htmlAttributes
                .Returns(tagBuilder)
                .Verifiable();

            if (method != FormMethod.Get)
            {
                htmlGenerator
                    .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                    .Returns(HtmlString.Empty)
                    .Verifiable();
            }

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginRouteForm(routeName, routeValues, method);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(RouteNameMethodAndHtmlAttributesDataSet))]
        public void BeginRouteFormWithRouteNameMethodAndHtmlAttributesParameters_CallsHtmlGeneratorWithExpectedValues(
            string routeName,
            FormMethod method,
            object htmlAttributes)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateRouteForm(
                    htmlHelper.ViewContext,
                    routeName,
                    null,   // routeValues
                    method.ToString().ToLowerInvariant(),
                    htmlAttributes))
                .Returns(tagBuilder)
                .Verifiable();

            if (method != FormMethod.Get)
            {
                htmlGenerator
                    .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                    .Returns(HtmlString.Empty)
                    .Verifiable();
            }

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginRouteForm(routeName, method, htmlAttributes);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(RouteNameMethodAndHtmlAttributesDataSet))]
        public void BeginRouteFormWithRouteNameMethodAndHtmlAttributesParameters_WithAntiforgery_CallsHtmlGeneratorWithExpectedValues(
            string routeName,
            FormMethod method,
            object htmlAttributes)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateRouteForm(
                    htmlHelper.ViewContext,
                    routeName,
                    null,   // routeValues
                    method.ToString().ToLowerInvariant(),
                    htmlAttributes))
                .Returns(tagBuilder)
                .Verifiable();
            htmlGenerator
                .Setup(g => g.GenerateAntiforgery(htmlHelper.ViewContext))
                .Returns(HtmlString.Empty)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginRouteForm(
                routeName,
                routeValues: null,
                method: method,
                antiforgery: true,
                htmlAttributes: htmlAttributes);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }

        [Theory]
        [MemberData(nameof(RouteNameMethodAndHtmlAttributesDataSet))]
        public void BeginRouteFormWithRouteNameMethodAndHtmlAttributesParameters_SuppressAntiforgery_CallsHtmlGeneratorWithExpectedValues(
            string routeName,
            FormMethod method,
            object htmlAttributes)
        {
            // Arrange
            var tagBuilder = new TagBuilder(tagName: "form");
            var htmlGenerator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
            var htmlHelper = DefaultTemplatesUtilities.GetHtmlHelper(htmlGenerator.Object);
            htmlGenerator
                .Setup(g => g.GenerateRouteForm(
                    htmlHelper.ViewContext,
                    routeName,
                    null,   // routeValues
                    method.ToString().ToLowerInvariant(),
                    htmlAttributes))
                .Returns(tagBuilder)
                .Verifiable();

            // Guards
            Assert.NotNull(htmlHelper.ViewContext);
            var writer = Assert.IsAssignableFrom<StringWriter>(htmlHelper.ViewContext.Writer);
            var builder = writer.GetStringBuilder();
            Assert.NotNull(builder);

            // Act
            var mvcForm = htmlHelper.BeginRouteForm(
                routeName,
                routeValues: null,
                method: method,
                antiforgery: false,
                htmlAttributes: htmlAttributes);

            // Assert
            Assert.NotNull(mvcForm);
            Assert.Equal("<form>", builder.ToString());
            htmlGenerator.Verify();
        }
    }
}