Examples of a collection fixture?

[jplumhoff]

Hi,

I'm attempting to write xunit integration tests for repositories that store data in postgresql. I'm using a collection fixture to create my postgresql container so it can be shared among all my repo test classes. The tests all work perfectly when I step through them in debug, but every one of them fails if I just run them. Each time, I get the same error for every test method:

Message: 
Npgsql.NpgsqlException : Exception while reading from stream
---- System.IO.EndOfStreamException : Attempted to read past the end of the stream.

  Stack Trace: 
NpgsqlReadBuffer.<Ensure>g__EnsureLong|41_0(NpgsqlReadBuffer buffer, Int32 count, Boolean async, Boolean readingNotifications)
NpgsqlConnector.RawOpen(SslMode sslMode, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
NpgsqlConnector.<Open>g__OpenCore|193_1(NpgsqlConnector conn, SslMode sslMode, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
NpgsqlConnector.Open(NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
ConnectorPool.OpenNewConnector(NpgsqlConnection conn, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
ConnectorPool.<Get>g__RentAsync|31_0(NpgsqlConnection conn, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
NpgsqlConnection.<Open>g__OpenAsync|45_0(Boolean async, CancellationToken cancellationToken)
SqlMapper.QueryAsync[T](IDbConnection cnn, Type effectiveType, CommandDefinition command) line 417
MaterialRepository.FindAsync(IQuerySpecification`1 querySpec) line 68
MaterialRepositoryTests.DeleteComponentMaterial() line 71
<>c.<ThrowAsync>b__128_0(Object state)
----- Inner Stack Trace -----
NpgsqlReadBuffer.<Ensure>g__EnsureLong|41_0(NpgsqlReadBuffer buffer, Int32 count, Boolean async, Boolean readingNotifications)

My first thought was that I was inadvertently re-using a DBconnection, but I create a new one for each test method. Since the tests all work if I create the container manually (without using testcontainers), I figure I have to be doing something wrong in the testcontainer fixture setup. Does anybody have an example of a collection fixture they use for multiple test classes that they could share? Super-extra bonus gratitude points if it's for a database...

[HofmeisterAn]

Can you share some of your code (especially the CollectionDefinition)? I use collection fixtures without any issues for databases too. It looks like your connection is broken somehow.

The tests all work perfectly when I step through them in debug, but every one of them fails if I just run them.

Sounds like a race condition. Did you check the wait strategy? Is the container ready to accept connections, etc.?

Edit: I attached a small example. Maybe that helps: PostgreSqlSample.zip

[jplumhoff]

Thanks for the example! But as it turns out, your comment proved absolutely correct - the container wasn't ready to accept connections. I had a WaitStrategy watching the logs for "database system is ready to accept connections". Apparently, that's not good enough. After seeing your response I changed it to the one you have in your postgres container:
Wait.ForUnixContainer().UntilCommandIsCompleted($"pg_isready -h 'localhost' -p '5432'")

Now everything is running perfectly. Thanks for the pointer! And just in general, thank you for this library - being able to run true integration tests against containers like this is a game changer...