WebApi2官网学习记录---单元测试

如果没有对应的web api模板，首先使用nuget进行安装

例子1：

ProductController 是以硬编码的方式使用StoreAppContext类的实例，可以使用依赖注入模式，在外部指定上下文实例

 public interface IStoreAppContext:IDisposable
    {
         DbSet<Product> Products { get; set; }
         int SaveChanges();
         void MarkAsModified(Product item);
    }

public class StoreAppContext : DbContext,IStoreAppContext
    {
        // You can add custom code to this file. Changes will not be overwritten.
        // 
        // If you want Entity Framework to drop and regenerate your database
        // automatically whenever you change your model schema, please use data migrations.
        // For more information refer to the documentation:
        // http://msdn.microsoft.com/en-us/data/jj591621.aspx
    
        public StoreAppContext() : base("name=StoreAppContext")
        {
        }

        public DbSet<Product> Products { get; set; }

        public void MarkAsModified(Product item)
        {
            Entry(item).State = EntityState.Modified;
        }
    }

public class ProductsController : ApiController
    {
        private IStoreAppContext db = new StoreAppContext();

        public ProductsController() { }

        public ProductsController(IStoreAppContext context)
       {
          db = context;
        }
        // GET: api/Products
        public IQueryable<Product> GetProducts()
        {
            return db.Products;
        }

        // GET: api/Products/5
        [ResponseType(typeof(Product))]
        public IHttpActionResult GetProduct(int id)
        {
            Product product = db.Products.Find(id);
            if (product == null)
            {
                return NotFound();
            }

            return Ok(product);
        }

        // PUT: api/Products/5
        [ResponseType(typeof(void))]
        public IHttpActionResult PutProduct(int id, Product product)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            if (id != product.Id)
            {
                return BadRequest();
            }

            db.MarkAsModified(product);

            try
            {
                db.SaveChanges();
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!ProductExists(id))
                {
                    return NotFound();
                }
                else
                {
                    throw;
                }
            }

            return StatusCode(HttpStatusCode.NoContent);
        }

        // POST: api/Products
        [ResponseType(typeof(Product))]
        public IHttpActionResult PostProduct(Product product)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            db.Products.Add(product);
            db.SaveChanges();

            return CreatedAtRoute("DefaultApi", new { id = product.Id }, product);
        }

        // DELETE: api/Products/5
        [ResponseType(typeof(Product))]
        public IHttpActionResult DeleteProduct(int id)
        {
            Product product = db.Products.Find(id);
            if (product == null)
            {
                return NotFound();
            }

            db.Products.Remove(product);
            db.SaveChanges();

            return Ok(product);
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                db.Dispose();
            }
            base.Dispose(disposing);
        }

        private bool ProductExists(int id)
        {
            return db.Products.Count(e => e.Id == id) > 0;
        }
    }

单元测试代码：

 public  class TestDbSet<T>:DbSet<T>,IQueryable,IEnumerable<T>
        where T:class
    {
        ObservableCollection<T> _data;
        IQueryable _query;

        public TestDbSet()
        {
            _data = new ObservableCollection<T>();
            _query = _data.AsQueryable();
        }

        public override T Add(T item)
        {
            _data.Add(item);
            return item;
        }

        public override T Remove(T item)
        {
            _data.Remove(item);
            return item;
        }

        public override T Attach(T item)
        {
            _data.Add(item);
            return item;
        }

        public override T Create()
        {
            return Activator.CreateInstance<T>();
        }

        public override TDerivedEntity Create<TDerivedEntity>()
        {
            return Activator.CreateInstance<TDerivedEntity>();
        }

        public override ObservableCollection<T> Local
        {
            get { return new ObservableCollection<T>(_data); }
        }

        Type IQueryable.ElementType
        {
            get { return _query.ElementType; }
        }

        System.Linq.Expressions.Expression IQueryable.Expression
        {
            get { return _query.Expression; }
        }

        IQueryProvider IQueryable.Provider
        {
            get { return _query.Provider; }
        }

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

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

class TestProductDbSet:TestDbSet<Product>
    {
        public override Product Find(params object[] keyValues)
        {
            return this.SingleOrDefault(p=>p.Id==(int)keyValues.Single());
        }
    }

 class TestStoreAppContext : IStoreAppContext
    {
        public TestStoreAppContext()
        {
            this.Products = new TestProductDbSet();
        }

        public System.Data.Entity.DbSet<Product> Products { get; set; }
       

        public int SaveChanges()
        {
            return 0;
        }

        public void MarkAsModified(Product item)
        {
            
        }

        public void Dispose()
        {
           
        }
    }

 public class TestProductController
    {
        [TestMethod]
        public void PostProduct_ShouldReturnSameProduct()
        {
            var controller = new ProductsController(new TestStoreAppContext());
            var item = GetDemoProduct();

            var result=controller.PostProduct(item) as  CreatedAtRouteNegotiatedContentResult<Product>;
            Assert.IsNotNull(result);
            Assert.AreEqual(result.RouteName, "DefaultApi");
            Assert.AreEqual(result.RouteValues["id"], result.Content.Id);
            Assert.AreEqual(result.Content.Name, item.Name);
        }
        [TestMethod]
        public void PutProduct_ShouldReturnStatusCode()
        {
            var controller = new ProductsController(new TestStoreAppContext());

            var item = GetDemoProduct();

            var result = controller.PutProduct(item.Id, item) as StatusCodeResult;
            Assert.IsNotNull(result);
            Assert.IsInstanceOfType(result, typeof(StatusCodeResult));
            Assert.AreEqual(HttpStatusCode.NoContent, result.StatusCode);
        }

        [TestMethod]
        public void PutProduct_ShouldFail_WhenDifferentID()
        {
            var controller = new ProductsController(new TestStoreAppContext());

            var badresult = controller.PutProduct(999, GetDemoProduct());
            Assert.IsInstanceOfType(badresult, typeof(BadRequestResult));
        }

        [TestMethod]
        public void GetProduct_ShouldReturnProductWithSameID()
        {
            var context = new TestStoreAppContext();
            context.Products.Add(GetDemoProduct());

            var controller = new ProductsController(context);
            var result = controller.GetProduct(3) as OkNegotiatedContentResult<Product>;

            Assert.IsNotNull(result);
            Assert.AreEqual(3, result.Content.Id);
        }

        [TestMethod]
        public void GetProducts_ShouldReturnAllProducts()
        {
            var context = new TestStoreAppContext();
            context.Products.Add(new Product { Id = 1, Name = "Demo1", Price = 20 });
            context.Products.Add(new Product { Id = 2, Name = "Demo2", Price = 30 });
            context.Products.Add(new Product { Id = 3, Name = "Demo3", Price = 40 });

            var controller = new ProductsController(context);
            var result = controller.GetProducts() as TestProductDbSet;

            Assert.IsNotNull(result);
            Assert.AreEqual(3, result.Local.Count);
        }

        [TestMethod]
        public void DeleteProduct_ShouldReturnOK()
        {
            var context = new TestStoreAppContext();
            var item = GetDemoProduct();
            context.Products.Add(item);

            var controller = new ProductsController(context);
            var result = controller.DeleteProduct(3) as OkNegotiatedContentResult<Product>;

            Assert.IsNotNull(result);
            Assert.AreEqual(item.Id, result.Content.Id);
        }
        Product GetDemoProduct()
        {
            return new Product() { Id = 3, Name = "Demo name", Price = 5 };
        }
    }

具体的代码参见：Mocking Entity Framework when Unit Testing ASP.NET Web API 2