Question

For my app i’m using a MVC-Store model.

The class DataStore holds a singleton object defaultstore which holds the data for the app.
Everything works out fine but i got some problems with my unit tests because i don’t want my tests mess up the data.

I would like to do the following but i don’t know how:

- (void)setUp
{
    [super setUp];

    //Backup my data
    //Clear coredata
}

- (void) testCreateSomeData
{
    //..Create some data, add it to the store, do some tests, etc..
}    

- (void)tearDown
{
    Put back my original data
    [super tearDown];
}

Oh btw, the init method of the DataStore looks like this, maybe thats of some help.

- (id) init
{
    //If we allready have a singleton object
    if(defaultStore){
        return defaultStore;
    }
    self = [super init];

    // Read in our .xcdatamodel file
    model = [[NSManagedObjectModel mergedModelFromBundles:nil] retain];

    NSPersistentStoreCoordinator *psc =
    [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:model];

    NSString *path = pathInDocumentDirectory(@"store.data");
    NSURL *storeURL = [NSURL fileURLWithPath:path];
    NSError *error = nil;

    if (![psc addPersistentStoreWithType:NSSQLiteStoreType
                           configuration:nil
                                     URL:storeURL
                                 options:nil
                                   error:&error]) {
        [NSException raise:@"Open failed" format:@"Reason: %@", [error localizedDescription]];
    }

    // Create the managed object context
    context = [[NSManagedObjectContext alloc] init];
    [context setPersistentStoreCoordinator:psc];
    [context setUndoManager:nil];

    [psc release];
    return self;
}

Answer 1

One option would be to have a designated init that takes a filename, and then have the default initializer pass in the normal file name. Then your tests could create a DataStore in a separate file, deleting it before running the tests and after, without touching your non-test data.