Bdtjtk

I'm trying to implement unit tests for a rest api I created. When I run the tests separately, they pass. But when I try to run all of them in 1 go, only 1 passes.

I know it has something to do with way I try to use the same data in evry test. I found a solution by using a new database(name) for every test. But I was wondering if this is the correct way to go about it? Since I think there has to be a cleaner way. I looked into the IDisposable method, but I coudn't get it to work.

This is how I put data in the db to test against:

public class GameTestShould

{

    private static GameService gameService;



    private readonly DbContextOptions<GameContext> options;

    public readonly Game testGame;

    public readonly User testUser;

    public Location testLocation;





    public GameTestShould()

    {

        //Arrange For the all tests

        options = new DbContextOptionsBuilder<GameContext>().UseInMemoryDatabase(databaseName: "GameTestDB").Options;

        //arrange

        using (var globalContext = new GameContext(options))

        {

            gameService = new GameService(globalContext);



            var testUser = new User()

            {

                Username = "tempUser",

                Password = "123456"

            };

            globalContext.Users.Add(testUser);

            var location2 = new Location()

            {

                LocName = "Standbeeld Stadhuis",

                LocLat = 51.220884,

                LocLong = 4.398995,

                LocDescription = "Standbeeld Vrijheid blijheid nabij stadhuis."

            };

            var location3 = new Location()

            {

                LocName = "Het Steen",

                LocLat = 51.222773,

                LocLong = 4.397367,

                LocDescription = "Het Steen"

            };

            var location4 = new Location()

            {

                LocName = "Pieter Paul Rubens",

                LocLat = 51.219326,

                LocLong = 4.401576,

                LocDescription = "Groenplaats, standbeeld Pieter Paul Rubens."

            };

            var location5 = new Location()

            {

                LocName = "Politiekantoor",

                LocLat = 51.230754,

                LocLong = 4.4174065,

                LocDescription = "Politiekantoor"

            };

            globalContext.Add(location2);

            globalContext.Add(location3);

            globalContext.Add(location4);

            globalContext.Add(location5);



            var suspect0 = new Suspect()

            {

                //  SuspectId = 1,

                SusName = "Miss Scarlett",

                SusWeapon = "Rope",

                SusDescription = "Ms. Vivienne Sakura Scarlet",

                SusImgUrl = "https://i.pinimg.com/originals/95/ce/3d/95ce3da06af8b1c09a4b2d4fa603b7a0.jpg",

            };

            var suspect1 = new Suspect()

            {

                SusName = "Mr. Green",

                SusWeapon = "Wooden cross",

                SusDescription = "Rev. Jonathan Green.",

                SusImgUrl = "https://pbs.twimg.com/profile_images/447953368271814657/Inf33QvJ.jpeg",

            };

            var suspect2 = new Suspect()

            {

                SusName = "Colonel Mustard",

                SusWeapon = "Gun",

                SusDescription = "Col. Michael Mustard",

                SusImgUrl = "https://static.independent.co.uk/s3fs-public/thumbnails/image/2016/07/04/08/unspecified-3.jpg?width=1368&height=912&fit=bounds&format=pjpg&auto=webp&quality=70",

            };



            var suspect3 = new Suspect()

            {

                SusName = "Dr.Orchid",

                SusWeapon = "Syringe",

                SusDescription = "A Doctor, Elegant ",

                SusImgUrl = "https://static.independent.co.uk/s3fs-public/thumbnails/image/2016/07/04/08/unspecified-4.jpg?width=1368&height=912&fit=bounds&format=pjpg&auto=webp&quality=70",

            };

            globalContext.Suspects.Add(suspect0);

            globalContext.Suspects.Add(suspect1);

            globalContext.Suspects.Add(suspect2);

            globalContext.Suspects.Add(suspect3);



            var clue0 = new Clue()

            {

                ClueName = "RansomPuzzle"

            };

            var clue1 = new Clue()

            {

                ClueName = "ARKnife"

            };

            var clue2 = new Clue()

            {

                ClueName = "ARRope"

            };

            globalContext.Clues.Add(clue0);

            globalContext.Clues.Add(clue1);

            globalContext.Clues.Add(clue2);

            globalContext.SaveChanges();

        }

    }

This is first test

   [Fact]

    public void Throw_AppExceptionTooManyItems_Over8ItemsAdded()

    {

        var options = new DbContextOptionsBuilder<GameContext>().UseInMemoryDatabase(databaseName: Guid.NewGuid().ToString()).Options; 



        using (var globalContext = new GameContext(options))

        {

            gameService = new GameService(globalContext);

            //act and assert 

            Exception ex = Assert.Throws<AppException>(() => gameService.CreateGame(1, 2));

            Assert.Contains("between", ex.Message);               

        }          

     }

2nd test. Here (I think) I make another db, but doesn't this just leave the data from previous test laying around? So if I were to make alot of tests, woudn't it slow down the test process?

   [Fact]

    public void Throw_AppExceptionWrongUser()

    {

        var options = new DbContextOptionsBuilder<GameContext>().UseInMemoryDatabase(databaseName: Guid.NewGuid().ToString()).Options;



        using (var globalContext = new GameContext(options))

        {

            gameService = new GameService(globalContext);

            //act and assert 

            Exception ex = Assert.Throws<AppException>(() => gameService.CreateGame(2, 3));

            Assert.Equal("User does not exist.", ex.Message);

        }            

    }

}

}

Are there better ways to go about this?

You need to give each test a new database otherwise, as you have seen, the db is reused for each test and can affect the results.

You can read the docs which uses a new InMemoryDatabase for each test. I give the database the same name as the test method (just for clarity).

You could move your db code to a private method and re-use that in each test e.g.

[Fact]

public void Throw_AppExceptionWrongUser()

{

    var options = new DbContextOptionsBuilder<GameContext>().UseInMemoryDatabase(databaseName: Guid.NewGuid().ToString()).Options;



        using (var globalContext = CreateNewContext(options))

        {

            gameService = new GameService(globalContext);

            //act and assert 

            Exception ex = Assert.Throws<AppException>(() => gameService.CreateGame(2, 3));

            Assert.Equal("User does not exist.", ex.Message);

        }            

    }

}



private GameContext CreateNewContext(DbContextOptions options)

{

    var globalContext = new GameContext(options);



    var testUser = new User()

        {

            Username = "tempUser",

            Password = "123456"

        };

    globalContext.Users.Add(testUser);



    return globalContext;

}

Performance shouldn't be affected that much, unless you are populating the in memory database with lots of data (but based on your example code that doesn't seem a problem). One way to find out is to write the tests and measure it :-)

If performance is an issue then you should consider only populating the database with the data you need for the specific test. I would recommend looking at the Builder pattern for populating the database if you want to go down that route.