jarl¶

An R linter that Scrutin can drive as a plugin. Unlike test tools, jarl checks code style rather than correctness. It maps lint diagnostics to warn events, so lint issues appear alongside test results in the TUI and web dashboard. jarl is opt-in: enable it with an explicit [[suite]] tool = "jarl" entry in .scrutin/config.toml, or pass files on the command line with -t jarl in file mode.

Installing jarl¶

jarl is not shipped with Scrutin. Follow the upstream install instructions at jarl.etiennebacher.com.

Directory structure¶

mypackage/
├── .scrutin/
│   └── config.toml    # [[suite]] tool = "jarl"
├── DESCRIPTION
├── jarl.toml          # optional: jarl's own config (rules, per-check knobs)
└── R/
    ├── math.R
    └── strings.R

Minimal example¶

.scrutin/config.toml

[[suite]]
tool = "jarl"

jarl.toml (optional)

jarl.toml is read by jarl itself (not by Scrutin) if you want to tune rules. Omit it to use jarl's built-in defaults.

R/math.R

# jarl flags T/F instead of TRUE/FALSE
is_positive <- function(x) {
  if (x > 0) T else F
}

Running¶

scrutin mypackage              # TUI
scrutin -r plain mypackage     # text output

jarl runs as its own suite alongside any other suites you've declared; suites run one at a time, but within the jarl suite every matched file is linted in parallel.

Plugin actions¶

Enter the Detail view for a jarl warning to see a numbered chip row of fix actions. Press the digit to invoke:

All four invoke jarl once with every matching file (after include / exclude filters) as trailing arguments. After a fix, the affected files are re-linted automatically.

Configuration¶

The minimal suite entry is just tool = "jarl". Override defaults on the same block:

[[suite]]
tool = "jarl"
# default `run` lints R/**/*.R; `watch` defaults to `run` (linters re-check what they operate on).
# Override to lint a different tree:
# run = ["scripts/**/*.R", "inst/examples/**/*.R"]

jarl has no separate source/watch list (it lints files directly and does not track dependencies between them).