public void CreateRandomFile_creates_expected_number_of_lines() { // arrange var factory = new QuoteFileFactory(); var allowedIdentifiers = new List <string> { "MSFT", "CSCO", "AMZN", "SBUX" }; var identifiers = new Identifiers(allowedIdentifiers); var expectedLines = 100; // act var file = factory.CreateRandomFile(identifiers, expectedLines); // assert var fileContents = file.ToString(); AssertHelper.AssertHasLines(fileContents, expectedLines); }