为什么我在单元测试中有迁移问题但在控制器 c# Web API 中没有

Question

Hello i have a project web api in c# and i want to write unit test to check my controller. But i find an error that i really don't understand. When i run my method in controller

public class TherapistsController : ApiController
{
    TherapistService _therapistService = new TherapistService();
    GeneralService _generalService = new GeneralService();

    //GET: api/Therapists/GetAllTherapists
    [HttpGet]
    [Route("api/Therapists/GetAllTherapists")]
    public IHttpActionResult GetTherapist()
    {
        var therapists = _therapistService.GetAllTherapist();
        if (therapists.Count() > 0)
            return Ok(therapists);
        return NotFound();
    }
}

it give me the result and it is fine

But if i run this method in a unit test

[TestClass]
public class UnitTest1
{
    [TestMethod]
    public void GetAllTherapistByOutletTest()
    {
        var therapists = new WebAPI.Controllers.TherapistsController();

        IHttpActionResult result = therapists.GetTherapist();

        Assert.IsInstanceOfType(result, typeof(OkResult));

    }
}

it give me the error

Like u see the error says that i need to update database by migration but it still give me same error after i migrate and update database. But when i run the method by calling API,it still give me the result like the first picture and no error. I debug both ways and they have same steps until method GetAll() in repository like u see in the above picture. I don't really know what wrong?

Repository

public class GenericRepository<TEntity> : IGenericRepository<TEntity> where TEntity : class
{
    protected readonly SpaDbContext db;
    public GenericRepository(SpaDbContext _db)
    {
        this.db = _db;
    }
    public void Add(TEntity entity)
    {
        db.Set<TEntity>().Add(entity);
    }

    public void AddRange(IEnumerable<TEntity> entities)
    {
        db.Set<TEntity>().AddRange(entities);
    }

    public void Detached(TEntity entity)
    {
        db.Entry<TEntity>(entity).State = EntityState.Detached;
    }

    public IEnumerable<TEntity> Find(Expression<Func<TEntity, bool>> predicate)
    {
        return db.Set<TEntity>().Where(predicate);
    }    

    public TEntity Get(Expression<Func<TEntity, bool>> predicate)
    {
        return db.Set<TEntity>().FirstOrDefault(predicate);
    }

    public TEntity Get(object Id)
    {
        return db.Set<TEntity>().Find(Id);
    }

    public IEnumerable<TEntity> GetAll()
    {
        return db.Set<TEntity>().ToList();
    }

    public void Remove(TEntity entity)
    {
        db.Set<TEntity>().Remove(entity);
    }

IRepository

namespace Repository
{
    public interface IGenericRepository<TEntity> where TEntity : class
    {
        IEnumerable<TEntity> GetAll();
        IEnumerable<TEntity> Find(Expression<Func<TEntity, bool>> predicate);
        TEntity Get(Expression<Func<TEntity, bool>> predicate);
        TEntity Get(object Id);
        void Add(TEntity entity);
        void AddRange(IEnumerable<TEntity> entities);
        void Update(TEntity entity);

        //void Remove(object Id);
        void Remove(TEntity entity);
        void RemoveRange(IEnumerable<TEntity> entities);

        void Detached(TEntity entity);

        IEnumerable<TEntity> GetByQuery(string query);
    }
}

Answer 1

Make sure you have set a valid connection string in test project as web api project

Answer 2

If you want do a real unit test with the controller methods you need use Mock services with this you will not have this kind of problems

https://learn.microsoft.com/en-us/aspnet/web-api/overview/testing-and-debugging/unit-testing-controllers-in-web-api