public void Download() { var options = new DbContextOptionsBuilder <AppDbContext>() .UseInMemoryDatabase(databaseName: "Download") .Options; using var context = new AppDbContext(options); Reports report4 = new Reports() { ReportId = 109 }; var _hostingEnviroment = new Mock <IWebHostEnvironment>(); _hostingEnviroment .Setup(m => m.EnvironmentName) .Returns("Hosting:UnitTestEnvironment"); _hostingEnviroment.Setup(p => p.ContentRootPath).Returns("C:\\Users\\finta\\source\\repos\\IncidentReportForm\\IncidentReportForm"); var service = new ReportRepository(context, _hostingEnviroment.Object); var testType = service.Download(report4); Assert.IsInstanceOfType(testType, typeof(FileStreamResult)); }