Mock Entity Framework FindAsync() method In entity framework, FindAsync() method has signature of: public virtual ValueTask<TEntity> FindAsync([CanBeNullAttribute] params object[] keyValues); Assume we have a method in DB repository that looks for brand information by brand ID: public async Task<Brand> GetBrandbyIdAsync(int brandId) { var brand = await _context.Brands.FindAsync(brandId).ConfigureAwait(false); return brand; } In order to make this method work, we need to mock the FindAsync call inside the method: var dbSetMock = CreateDbSetMock(brands ); dbSetMock.Setup(m => m.FindAsync(It.IsAny<object[]>())).Returns((object[] r) => ...