Entity Framework Mocking using SQL Server LocalDB
// Assuming you have `AppDbContext` as your EF DbContext in side your actual application project
// For test purposes, you will have to use AppDbTestContext
// or you can use AppDbTestContext as dependency in your DI container
public class AppDbTestContext : ShopContext
{
// this is important
// since databases are dynamically created and destroyed
// MockDatabaseContext.Current.ConnectionString contains
// correct database for current test context
// MockDatabaseContext.Current will work correctly with async await
// without worrying about passing context
public AppDbTestContext(DbContextOptions options): base(options)
{
}
public AppDbTestContext(): base(Create(MockDatabaseContext.Current.ConnectionString))
{
}
public AppDbTestContext(string cnstr) : base(Create(cnstr)) {
}
public static DbContextOptions<AppDbTestContext> Create(string connectionString) {
DbContextOptionsBuilder<AppDbTestContext> builder = new DbContextOptionsBuilder<AppDbTestContext>();
builder.UseSqlServer(connectionString);
return builder.Options;
}
}
public abstract class BaseTest :
MockSqlDatabaseContext<AppDbTestContext>
{
public BaseTest(ITestOutputHelper writer)
{
this.Writer = writer;
}
protected override void DumpLogs()
{
this.Writer.WriteLine(base.GeneratedLog);
}
public ITestOutputHelper Writer { get; private set; }
public AppDbTestContext CreateContext()
{
AppDbTestContext db = new AppDbTestContext(ConnectionString);
db.Database.EnsureCreated();
Seed(db);
return db;
}
public void Seed(AppDbTestContext db) {
db.Products.Add(new Product {
Name = "a"
});
db.SaveChanges();
DoNotDelete = true;
}
}Test Case
public class DbTest : BaseTest {
[Fact]
public void Test1() {
using(var db = CreateContext()) {
// do test here...
}
// after this test is finished, database will be deleted automatically
// if you want to prevent deletion of database to investigate anything
// uncomment following
// DoNotDelete = true;
}
}