campus-errand/server.tests/PriceChangeDifferencePropertyTests.cs

using System.Net;
using System.Net.Http.Headers;
using System.Net.Http.Json;
using System.Text.Json;
using CampusErrand.Data;
using CampusErrand.Models;
using FsCheck;
using FsCheck.Xunit;
using Microsoft.AspNetCore.Mvc.Testing;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;

namespace CampusErrand.Tests;

/// <summary>
/// Property 16: 改价差额计算
/// 对任意改价申请，当新价格高于原价时应产生补缴金额（新价 - 原价），
/// 当新价格低于原价时应产生退款金额（原价 - 新价）。
/// **Feature: login-and-homepage, Property 16: 改价差额计算**
/// **Validates: Requirements 19.1, 19.2**
/// </summary>
public class PriceChangeDifferencePropertyTests : IDisposable
{
    private const string JwtSecret = "YourSuperSecretKeyForJwtTokenGeneration_AtLeast32Chars!";
    private const string JwtIssuer = "CampusErrand";
    private const string JwtAudience = "CampusErrandApp";

    private readonly List<WebApplicationFactory<Program>> _factories = [];

    private WebApplicationFactory<Program> CreateFactory(string dbName)
    {
        var factory = new WebApplicationFactory<Program>()
            .WithWebHostBuilder(builder =>
            {
                builder.ConfigureServices(services =>
                {
                    var efDescriptors = services
                        .Where(d =>
                            d.ServiceType.FullName?.Contains("EntityFrameworkCore") == true
                            || d.ServiceType == typeof(DbContextOptions<AppDbContext>)
                            || d.ServiceType == typeof(DbContextOptions)
                            || d.ImplementationType?.FullName?.Contains("EntityFrameworkCore") == true)
                        .ToList();
                    foreach (var d in efDescriptors) services.Remove(d);

                    services.AddDbContext<AppDbContext>(options =>
                        options.UseInMemoryDatabase(dbName));
                });
            });
        _factories.Add(factory);
        return factory;
    }

    private static string GenerateToken(int userId, string role = "User")
    {
        var key = new Microsoft.IdentityModel.Tokens.SymmetricSecurityKey(
            System.Text.Encoding.UTF8.GetBytes(JwtSecret));
        var credentials = new Microsoft.IdentityModel.Tokens.SigningCredentials(
            key, Microsoft.IdentityModel.Tokens.SecurityAlgorithms.HmacSha256);
        var claims = new[]
        {
            new System.Security.Claims.Claim(System.Security.Claims.ClaimTypes.NameIdentifier, userId.ToString()),
            new System.Security.Claims.Claim(System.Security.Claims.ClaimTypes.Role, role)
        };
        var token = new System.IdentityModel.Tokens.Jwt.JwtSecurityToken(
            issuer: JwtIssuer, audience: JwtAudience, claims: claims,
            expires: DateTime.UtcNow.AddHours(1), signingCredentials: credentials);
        return new System.IdentityModel.Tokens.Jwt.JwtSecurityTokenHandler().WriteToken(token);
    }

    /// <summary>
    /// 准备进行中的代购订单（含商品金额，支持佣金和商品改价）
    /// </summary>
    private int SeedInProgressOrder(WebApplicationFactory<Program> factory, string suffix, decimal commission, decimal goodsAmount)
    {
        using var scope = factory.Services.CreateScope();
        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();

        db.Users.Add(new User { Id = 100, OpenId = $"owner_{suffix}", Phone = "13900000001", Nickname = "单主", CreatedAt = DateTime.UtcNow });
        db.Users.Add(new User { Id = 200, OpenId = $"runner_{suffix}", Phone = "13900000002", Nickname = "跑腿", Role = UserRole.Runner, CreatedAt = DateTime.UtcNow });
        db.RunnerCertifications.Add(new RunnerCertification { UserId = 200, RealName = "测试", Phone = "13900000002", Status = CertificationStatus.Approved, CreatedAt = DateTime.UtcNow });

        var order = new Order
        {
            OrderNo = $"ORD{Guid.NewGuid():N}"[..20],
            OwnerId = 100, RunnerId = 200,
            OrderType = OrderType.Purchase, Status = OrderStatus.InProgress,
            ItemName = "测试商品", DeliveryLocation = "测试地点",
            Phone = "13800138000", Commission = commission,
            GoodsAmount = goodsAmount, TotalAmount = goodsAmount + commission,
            CreatedAt = DateTime.UtcNow, AcceptedAt = DateTime.UtcNow
        };
        db.Orders.Add(order);
        db.SaveChanges();
        return order.Id;
    }

    /// <summary>
    /// 属性：改价差额 = 新价格 - 原价格（正数为补缴，负数为退款）
    /// </summary>
    [Property(MaxTest = 20)]
    public bool 改价差额等于新价减原价(PositiveInt seed)
    {
        // 生成合理的原始佣金和新佣金
        var originalCommission = 1.0m + (seed.Get % 100);
        var newCommission = 1.0m + ((seed.Get * 7) % 100);

        var dbName = $"pricediff_{Guid.NewGuid()}";
        using var factory = CreateFactory(dbName);
        var orderId = SeedInProgressOrder(factory, Guid.NewGuid().ToString("N"), originalCommission, 50.0m);

        var client = factory.CreateClient();
        // 单主发起改价
        client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", GenerateToken(100));

        var response = client.PostAsJsonAsync($"/api/orders/{orderId}/price-change",
            new { ChangeType = "Commission", NewPrice = newCommission }).Result;

        if (response.StatusCode != HttpStatusCode.Created) return false;

        var json = response.Content.ReadFromJsonAsync<JsonElement>().Result;
        var difference = json.GetProperty("difference").GetDecimal();
        var expectedDifference = newCommission - originalCommission;

        return difference == expectedDifference;
    }

    /// <summary>
    /// 属性：同意改价后订单金额正确更新
    /// </summary>
    [Property(MaxTest = 20)]
    public bool 同意改价后订单金额正确更新(PositiveInt seed)
    {
        var originalCommission = 1.0m + (seed.Get % 50);
        var newCommission = 1.0m + ((seed.Get * 3) % 50);
        var goodsAmount = 10.0m + (seed.Get % 90);

        var dbName = $"priceaccept_{Guid.NewGuid()}";
        using var factory = CreateFactory(dbName);
        var orderId = SeedInProgressOrder(factory, Guid.NewGuid().ToString("N"), originalCommission, goodsAmount);

        var client = factory.CreateClient();

        // 单主发起佣金改价
        client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", GenerateToken(100));
        var createResp = client.PostAsJsonAsync($"/api/orders/{orderId}/price-change",
            new { ChangeType = "Commission", NewPrice = newCommission }).Result;
        if (createResp.StatusCode != HttpStatusCode.Created) return false;

        var createJson = createResp.Content.ReadFromJsonAsync<JsonElement>().Result;
        var changeId = createJson.GetProperty("id").GetInt32();

        // 跑腿同意改价
        client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", GenerateToken(200, "Runner"));
        var acceptResp = client.PutAsJsonAsync($"/api/orders/{orderId}/price-change/{changeId}",
            new { Action = "Accepted" }).Result;
        if (acceptResp.StatusCode != HttpStatusCode.OK) return false;

        // 验证订单金额
        using var scope = factory.Services.CreateScope();
        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
        var order = db.Orders.Find(orderId)!;

        return order.Commission == newCommission
            && order.TotalAmount == goodsAmount + newCommission;
    }

    public void Dispose()
    {
        foreach (var f in _factories) f.Dispose();
        _factories.Clear();
    }
}