"helloweb" example webserver crashes on first http request receipt

[Ian McLerran]

When running the "helloweb" example webserver from the readme.md file (updated to use the 0.2.0 release), the webserver runs successfully, but as soon as a request is made to the server by loading 127.0.0.1:8000 in a browser, the application crashes with the following message (note that no backtrace is printed):

thread 'tokio-runtime-worker' panicked at 'The Roc app crashed with: Integer multiplication overflowed!', src/lib.rs:46:5
stack backtrace:

Note that I am using Roc version: roc_nightly-macos_apple_silicon-2023-12-29-4569770c82c

[Anton-4]

Thanks for reporting this @imclerran! I have not had the time to set up proper testing for basic-webserver yet, hence this easily detectable bug. I'll do some debugging.

[Anton-4]

I could not reproduce this with the same nightly and this source code:

app "helloweb"
    packages { pf: "https://github.com/roc-lang/basic-webserver/releases/download/0.2.0/J6CiEdkMp41qNdq-9L3HGoF2cFkafFlArvfU1RtR4rY.tar.br" }
    imports [
        pf.Stdout,
        pf.Task.{ Task },
        pf.Http.{ Request, Response },
        pf.Utc,
    ]
    provides [main] to pf

main : Request -> Task Response []
main = \req ->

    # Log request date, method and url
    date <- Utc.now |> Task.map Utc.toIso8601Str |> Task.await
    {} <- Stdout.line "\(date) \(Http.methodToStr req.method) \(req.url)" |> Task.await

    Task.ok { status: 200, headers: [], body: Str.toUtf8 "<b>Hello, world!</b>\n" }

❯ ./roc examples/helloweb.roc 
Listening on localhost port 8000
2024-01-01T12:59.51Z GET /
2024-01-01T12:59.51Z GET /favicon.ico

Can you share your exact code and roc command @imclerran?

[Ian McLerran]

Yes, here is my code:

app "helloweb"
    packages { pf: "https://github.com/roc-lang/basic-webserver/releases/download/0.2.0/J6CiEdkMp41qNdq-9L3HGoF2cFkafFlArvfU1RtR4rY.tar.br" }
    imports [
        pf.Stdout,
        pf.Task.{ Task },
        pf.Http.{ Request, Response },
        pf.Utc,
    ]
    provides [main] to pf

main : Request -> Task Response []
main = \req ->

    # Log request date, method and url
    date <- Utc.now |> Task.map Utc.toIso8601Str |> Task.await
    {} <- Stdout.line "\(date) \(Http.methodToStr req.method) \(req.url)" |> Task.await

    Task.ok { status: 200, headers: [], body: Str.toUtf8 "<b>Hello, world!</b>\n" }

Note that this is identical to the code in the readme, except that the package has been updated to the 0.2.0 release of the platform. Also note that I get the same error when using the 0.1 release.

I also get the same error when running the command.roc example, although since I don't have the repo locally, I am again using the url to download the platform files (both 0.2.0 and 0.1), but otherwise leaving the code unchanged.

[Ian McLerran]

My roc command was roc dev helloweb.roc. However when trying again today, I can't reproduce the error either.

Not sure what happened as I tried multiple times yesterday with multiple versions of server code, and multiple platform versions. Every run resulted in a crash on the first HTTP request.

Given the fact that I can't reproduce, I think it's safe to close this issue.