Compiler messages cause tests to fail

Challenges
1

I’m trying to go through Stage #ND9 (Count rows in a table), but I hit a wall. The test suite looks at the CLI output, but the Gleam compiler messages cause the tests to fail. I need a way to silence those, but I have no idea how. Any pointers? Here’s what it dumps on the terminal.

   Compiled in 0.03s
    Running sqlite.main
=ERROR REPORT==== 8-Aug-2024::19:01:39.036822 ===
backend port not found: inotifywait

107

107 is the actual expected output. Anything before that is stuff that I want to silence.

Another way would be getting the test suite to ignore the compiler output, but I think that’s not how this platform works, right?

One interesting detail is that I have gone through a lot of challenge stages with the Gleam compiler already, and this never came up as a problem. Could there be something wrong with how this stage specifically expects the output to be?

Update

Just found out about the new codecrafters test --previous flag and ran a test on the previous stages. The compiler messages are there all the time, but the tests don’t complain at all, and pass. Only #ND9 seems to be affected.

1 Like
2

Ah, nice catch. This is something I’m working on fixing (we’re going to push an upstream patch for Add --no-print-progress flag to gleam run and gleam build · Issue #2299 · gleam-lang/gleam · GitHub). In the meantime, I’ve got a workaround for you:

Could you try editing .codecrafters/run.sh to look like this?

That should filter out the messages for now.

With most languages this isn’t a problem, since debug messages are printed to stderr and not stdout. Looks like Gleam prints these to stdout though.

3

Other stages pass ok with the same messages. Is the testing different for #ND9 ? I went through the tester repo but couldn’t figure out where exactly it asserts the output.

4 
exec gleam run --module sqlite -- "$@" | grep -v "Compiled" | grep -v "Running" | grep -v "=ERROR REPORT=" | grep -v "backend port" | grep -v "^\n"

This is what I ended up with, unable to filter out that last newline. Is there a way to fix how the test evaluates the output?

[tester::#ND9] Running tests for Stage #ND9 (Count rows in a table)
[tester::#ND9] $ ./your_program.sh test.db "select count(*) from pistachio"
[your_program]
[your_program] 142
[tester::#ND9] Expected "142\n" as stdout, got: "\n142\n"
[tester::#ND9] Test failed (try setting 'debug: true' in your codecrafters.yml to see more details)
5

Here’s a fix for you:

Use the following command in .codecrafters/run.sh and your_program.sh:

grep -vE "Compiled|Running|=ERROR REPORT=|backend port|^$"` 
# The only change was from ^\r?\n to ^$

@edgerunner Could you give this a try, and please let me know how it goes?

I was also baffled by why the extra \n couldn’t be eliminated. Turns out that grep works on a line-by-line basis, meaning \n was already consumed by grep , leaving us just blank lines which can’t be matched by ^\r?\n.

1 Like
6

Louis (Gleam maintainer) said that the fix should land in the next release within the next few weeks, we’ll keep this open until that’s landed!

1 Like
7

This worked with a little bit of escaping: ^\$ because $ is a replacement character.

Coincidentally, I learned a new thing about grep today, which affects how I approach the “Make your own GREP” challenge :slight_smile:

1 Like
8

Yes, it’s already in the nightly. The only question mark is how do I upgrade the gleam version without starting a fresh repo. (Which I’d rather not because I use commit messages as code comments, thanks to the git-lens feature in Zed)

9

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