Some multiline code in R console not working a

[jonvanausdeln]

System details:

Windows, Ubuntu 22

Positron and OS details:

Dev build after ARK bumped to 0.1.143

Interpreter details:

R 4.4.1

Describe the issue:

Found in our automated ConsoleInput tests. This appears to be happening after the latest ARK version bump

Steps to reproduce the issue:

1. Start and R Console
2. Paste the following into the console

val <- readline(prompt = "Enter your name: ")
cat(sprintf('Hello %s!\n', val))

Results in

Expected or desired behavior:

Were there any error messages in the UI, Output panel, or Developer Tools console?

[DavisVaughan]

A little more info, looks like we need to recognize if we are in a readline state and pause on sending pending lines if we detect that

(To be clear, to reproduce you have to select both lines at once and send them all over)

[testlabauto]

There may be a little extra diagnostic info on OSX. Here is what I see with that test:

[R] /Users/christophermead/posit/positron/extensions/positron-r/resources/ark/ark --connection_file /var/folders/rc/l24758015ggb5438npy04wtc0000gn/T/kernel-yfbhov/connection.json --log /var/folders/rc/l24758015ggb5438npy04wtc0000gn/T/kernel-yfbhov/kernel.log --startup-file /Users/christophermead/posit/positron/extensions/positron-r/resources/scripts/startup.R --session-mode console -- --interactive --no-restore-data
[R]   2024-10-04T17:46:02.111723Z ERROR  Panic! In file 'crates/ark/src/interface.rs' at line 686: internal error: entered unreachable code: Incomplete input in `ReadConsole` handler
[R] 
[R] Backtrace:
[R]    0: std::backtrace::Backtrace::create
[R]    1: ark::main::{{closure}}::{{closure}}
[R]    2: ark::main::{{closure}}
[R]    3: std::panicking::rust_panic_with_hook
[R]    4: std::panicking::begin_panic_handler::{{closure}}
[R]    5: std::sys::backtrace::__rust_end_short_backtrace
[R]    6: _rust_begin_unwind
[R]    7: core::panicking::panic_fmt
[R]    8: ark::interface::RMain::read_console
[R]    9: harp::exec::try_catch::callback
[R]   10: R_withCallingErrorHandler
[R]              at /Volumes/Builds/R4/R-4.3.3/src/main/errors.c:2613:16
[R]   11: harp::exec::top_level_exec::callback
[R]   12: R_ToplevelExec
[R]              at /Volumes/Builds/R4/R-4.3.3/src/main/context.c:799:2
[R]   13: harp::exec::r_sandbox
[R]   14: _r_read_console
[R]   15: Rf_ReplIteration
[R]              at /Volumes/Builds/R4/R-4.3.3/src/main/main.c:210:10
[R]   16: R_ReplConsole
[R]              at /Volumes/Builds/R4/R-4.3.3/src/main/main.c:314:11
[R]   17: run_Rmainloop
[R]              at /Volumes/Builds/R4/R-4.3.3/src/main/main.c:1200:5
[R]   18: ark::interface::RMain::start
[R]   19: ark::main
[R]   20: std::sys::backtrace::__rust_begin_short_backtrace
[R]   21: std::rt::lang_start::{{closure}}
[R]   22: std::rt::lang_start_internal
[R]   23: _main
[R] 
[R]     at crates/ark/src/main.rs:279
[R] 
[R] 
[R] *** Log started at Fri Oct  4 11:46:02 MDT 2024
[R] *** Command line:
[R] /Users/christophermead/posit/positron/extensions/positron-r/resources/ark/ark --connection_file /var/folders/rc/l24758015ggb5438npy04wtc0000gn/T/kernel-OLvWNf/connection.json --log /var/folders/rc/l24758015ggb5438npy04wtc0000gn/T/kernel-OLvWNf/kernel.log --startup-file /Users/christophermead/posit/positron/extensions/positron-r/resources/scripts/startup.R --session-mode console -- --interactive --no-restore-data

[jonvanausdeln]

QA Note: we are skipping the automated test (see #4902 ) and it will need to be re-enabled after this is fixed.

[lionel-]

I think we had decided not to maintain any internal stacks of pending inputs in the case of nested prompts, in particular debug prompts, because doing so would be incompatible with the frontend-side expression splitting (#1326). Also we thought it'd be fine because this is the RStudio behaviour.

But now that I think of it, since in the Jupyter protocol readline prompts are nested in execute-request prompts, the frontend-side splitting will not result in pending expressions being sent to readline prompts. So there's a fundamental distinction between browser and readline prompts and I agree the behaviour change highlighted here should be fixed.

Worth noting that we have plans for browser prompts to become readline prompts in notebook-mode, because right now the behaviour is confusing (posit-dev/ark#572). I wonder if we should do the same for browser prompts in console mode to benefit from the same nested structure.