flint
is a small R package to find and replace lints in R code.
- Lints detection with
lint()
- Automatic replacement of lints with
fix()
- Compatibility with (some) lintr rules
- Fast
flint
is powered by astgrepr
, which is itself built on the Rust crate ast-grep
.
Installation
install.packages('flint', repos = c('https://etiennebacher.r-universe.dev'))
Usage
Optional setup:
-
setup_flint()
: creates the folderflint
and populates it with built-in rules as well as a cache file. You can modify those rules or add new ones if you want more control.
You can use flint
as-is, without any setup. However, running setup_flint()
enables the use of caching, meaning that the subsequent runs will be faster. It is also gives you a place where you can store custom rules for your project/package.
The everyday usage consists of two functions:
-
lint()
looks for lints in R files; -
fix()
looks for lints in R files and automatically applies their replacement (if any).
One can also experiment with flint::lint_text()
and flint::fix_text()
:
flint::lint_text("
any(is.na(x))
any(duplicated(y))
")
#> Original code: any(is.na(x))
#> Suggestion: anyNA(x) is better than any(is.na(x)).
#> Rule ID: any_na-1
#>
#> Original code: any(duplicated(y))
#> Suggestion: anyDuplicated(x, ...) > 0 is better than any(duplicated(x), ...).
#> Rule ID: any_duplicated-1
flint::fix_text("
any(is.na(x))
any(duplicated(y))
")
#> Old code:
#> any(is.na(x))
#> any(duplicated(y))
#>
#> New code:
#> anyNA(x)
#> anyDuplicated(y) > 0
Real-life examples
I tested flint
on several packages while developing it. I proposed some pull requests for those packages. Here are a few:
-
ggplot2
: #6050 and #6051 -
marginaleffects
: #1171 and #1177 -
targets
: #1325 -
tinytable
: #325 -
usethis
: #2048
Except for some manual tweaks when the replacement was wrong (I was testing flint
after all), all changes were generated by flint::fix_package()
or flint::fix_dir(<dirname>)
.
Comparison with existing tools
The most used tool for lints detection in R is lintr
. However, lintr
’s performance is not optimal when it is applied on medium to large packages. Also, lintr
cannot perform automatic replacement of lints.
styler
is a package to clean code by fixing indentation and other things, but doesn’t perform code replacement based on lints.
flint
is quite performant. This is a small benchmark on 3.5k lines of code with a few linters:
file <- system.file("bench/test.R", package = "flint")
bench::mark(
lintr = lintr::lint(
file, linters = list(lintr::any_duplicated_linter(), lintr::any_is_na_linter(),
lintr::matrix_apply_linter(), lintr::function_return_linter(),
lintr::lengths_linter(), lintr::T_and_F_symbol_linter(),
lintr::undesirable_function_linter(), lintr::expect_length_linter())
),
flint = flint::lint(
file, linters = list(flint::any_duplicated_linter(), flint::any_is_na_linter(),
flint::matrix_apply_linter(), flint::function_return_linter(),
flint::lengths_linter(), flint::T_and_F_symbol_linter(),
flint::undesirable_function_linter(), flint::expect_length_linter()),
verbose = FALSE,
open = FALSE
),
check = FALSE
)
#> Warning: Some expressions had a GC in every
#> iteration; so filtering is disabled.
#> # A tibble: 2 × 6
#> expression min median `itr/sec` mem_alloc
#> <bch:expr> <bch:tm> <bch:tm> <dbl> <bch:byt>
#> 1 lintr 1.89s 1.89s 0.528 308.57MB
#> 2 flint 101.64ms 102.4ms 9.71 1.67MB
#> # ℹ 1 more variable: `gc/sec` <dbl>
Contributing
Did you find some bugs or some errors in the documentation? Do you want flint
to support more rules?
Take a look at the contributing guide for instructions on bug report and pull requests.
Acknowledgements
The website theme was heavily inspired by Matthew Kay’s ggblend
package: https://mjskay.github.io/ggblend/.