Unit Testing: No database provider has been configured for this DbContext

Question

So, I am trying to Unit Test my project, and the UnitTests.cs file has 8 tests, out of which 6 pass but 2 fail, the two that fail gives me the error of "No database provider has been configured for this DbContext." the UnitTests.cs file:

private readonly CatalogItemContext _context;

private Microsoft.EntityFrameworkCore.DbContextOptionsBuilder<CatalogItemContext> obj;

public UnitTests()
{
    obj = new DbContextOptionsBuilder<CatalogItemContext>();
    _context = new CatalogItemContext(obj.Options);
}

[Fact]
public void Get_WhenCalled_ReturnsAllItems()
{
    CatalogController cc = new CatalogController(_context);
    var test = cc.GetItems().Result;
    var okResult = test.Result as OkObjectResult;

    var items = Assert.IsType<List<CatalogItem>>(okResult.Value);
    Assert.Equal(3, items.Count);
}

[Fact]
public void Get_WhenCalled_ReturnsAllProductsTypes()
{
    CatalogController cc = new CatalogController(_context);
    var test = cc.GetTypes().Result;
    var okResult = test.Result as OkObjectResult;
    var Expected = typeof(OkObjectResult);
    var items = Assert.IsType<List<CatalogType>>(okResult.Value);
    Assert.Equal(3, items.Count);
}

My Startup.cs contains the following:

string connectionString = Configuration.GetConnectionString("DefaultConnection");

services.AddDbContext<CatalogItemContext>(opt => opt.UseSqlServer(connectionString));

services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();

And Context File is as follows:

public class CatalogItemContext : DbContext
{
    public CatalogItemContext(DbContextOptions<CatalogItemContext> options) : base(options)
    {
    }
    public DbSet<CatalogItem> CatalogItem { get; set; }
    public DbSet<CatalogType> CatalogType { get; set; }

    protected override void OnModelCreating(ModelBuilder builder)
    {
        builder.HasDefaultSchema("Catalog");
        builder.ApplyConfiguration(new CatalogTypeEntityTypeConfiguration());
        builder.ApplyConfiguration(new CatalogItemEntityTypeConfiguration());
    }     
}


public class CatalogContextDesignFactory : IDesignTimeDbContextFactory<CatalogItemContext>
{
    public CatalogItemContext CreateDbContext(string[] args)
    {
        var optionsBuilder =  new DbContextOptionsBuilder<CatalogItemContext>()
            .UseSqlServer("--REDACTED CONNECTION STRING--",
            x => x.MigrationsHistoryTable("__EFMigrationHistory", "catalog"));

        return new CatalogItemContext(optionsBuilder.Options);
    }

Can someone please shed some light on what I can do to make it work?

EDIT: Error which are appearing: PS: I am using VSCode.

    [xUnit.net 00:00:01.26]     UnitTests.Get_WhenCalled_ReturnsAllProductsTypes [FAIL]

[xUnit.net 00:00:01.27]     UnitTests.Get_WhenCalled_ReturnsAllItems [FAIL]

  X UnitTests.Get_WhenCalled_ReturnsAllProductsTypes [2ms]
  Error Message:
   System.AggregateException : One or more errors occurred. (No database provider has been configured for this DbContext. A provider can be configured by overriding the DbContext.OnConfiguring method or by using AddDbContext on the application service provider. If AddDbContext 
is used, then also ensure that your DbContext type accepts a DbContextOptions<TContext> object in its constructor and passes it to the base constructor for DbContext.)
---- System.InvalidOperationException : No database provider has been configured for this DbContext. A provider can be configured by overriding the DbContext.OnConfiguring method or by using AddDbContext on the application service provider. If AddDbContext is used, then also ensure that your DbContext type accepts a DbContextOptions<TContext> object in its constructor and passes it to the base constructor for DbContext.
  Stack Trace:
     at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
   at UnitTests.Get_WhenCalled_ReturnsAllProductsTypes() in --Location redacted--\Test\UnitTests.cs:line 33
----- Inner Stack Trace -----
   at Microsoft.EntityFrameworkCore.Internal.DbContextServices.Initialize(IServiceProvider scopedProvider, IDbContextOptions contextOptions, DbContext context)
   at Microsoft.EntityFrameworkCore.DbContext.get_InternalServiceProvider()
   at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies()
   at Microsoft.EntityFrameworkCore.DbContext.get_Model()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.get_EntityType()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.get_EntityQueryable()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.Microsoft.EntityFrameworkCore.Query.Internal.IAsyncEnumerableAccessor<TEntity>.get_AsyncEnumerable()
   at Microsoft.EntityFrameworkCore.Extensions.Internal.QueryableExtensions.AsAsyncEnumerable[TSource](IQueryable`1 source)
   at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)
   at --Redacted--.Controllers.CatalogController.GetTypes() in --Location Redacted--\src\--Redacted--\Controllers\CatalogController.cs:line 43

  X UnitTests.Get_WhenCalled_ReturnsAllItems [2ms]
  Error Message:
   System.AggregateException : One or more errors occurred. (No database provider has been configured for this DbContext. A provider can be configured by overriding the DbContext.OnConfiguring method or by using AddDbContext on the application service provider. If AddDbContext 
is used, then also ensure that your DbContext type accepts a DbContextOptions<TContext> object in its constructor and passes it to the base constructor for DbContext.)
---- System.InvalidOperationException : No database provider has been configured for this DbContext. A provider can be configured by overriding the DbContext.OnConfiguring method or by using AddDbContext on the application service provider. If AddDbContext is used, then also ensure that your DbContext type accepts a DbContextOptions<TContext> object in its constructor and passes it to the base constructor for DbContext.
  Stack Trace:
     at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
   at UnitTests.Get_WhenCalled_ReturnsAllItems() in --Location Redacted--\src\--Redacted--\Test\UnitTests.cs:line 22
----- Inner Stack Trace -----
   at Microsoft.EntityFrameworkCore.Internal.DbContextServices.Initialize(IServiceProvider scopedProvider, IDbContextOptions contextOptions, DbContext context)
   at Microsoft.EntityFrameworkCore.DbContext.get_InternalServiceProvider()
   at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies()
   at Microsoft.EntityFrameworkCore.DbContext.get_Model()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.get_EntityType()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.get_EntityQueryable()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.Microsoft.EntityFrameworkCore.Query.Internal.IAsyncEnumerableAccessor<TEntity>.get_AsyncEnumerable()
   at Microsoft.EntityFrameworkCore.Extensions.Internal.QueryableExtensions.AsAsyncEnumerable[TSource](IQueryable`1 source)
   at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)
   at --Redacted--.Controllers.CatalogController.GetItems() in --Location Redacted--\src\Redacted\Controllers\CatalogController.cs:line 32


Test Run Failed.
Total tests: 8
     Passed: 6
     Failed: 2
 Total time: 2.1150 Seconds

Answer 1

Compare these two pieces of code :

obj = new DbContextOptionsBuilder<CatalogItemContext>();
_context = new CatalogItemContext(obj.Options);

and

var optionsBuilder =  new DbContextOptionsBuilder<CatalogItemContext>()
    .UseSqlServer("--REDACTED CONNECTION STRING--",
    x => x.MigrationsHistoryTable("__EFMigrationHistory", "catalog"));

return new CatalogItemContext(optionsBuilder.Options);

One has something the other is missing.

Also note that the code in Startup.cs is never involved in execution of your tests. I recommend putting breakpoints in code in Startup.cs and in CatalogContextDesignFactory.CreateDbContext and see if they are hit when you debug the tests.