README.Rmd

---
output: github_document
---

<!-- README.md is generated from README.Rmd. Please edit that file -->

```{r, include = FALSE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  fig.path = "man/figures/README-",
  out.width = "100%"
)
```

# chk <img src="man/figures/logo.png" style="float: right;" />

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`chk` is an R package for developers to check user-supplied function arguments.

It is designed to be simple, customizable and fast.


## Installation

To install the latest release version from CRAN.
```r
install.packages("chk")
```

To install the latest development version from [r-universe](https://poissonconsulting.r-universe.dev/chk).
```r
install.packages("chk", repos = c("https://poissonconsulting.r-universe.dev", "https://cloud.r-project.org"))
```

To install the latest development version from [GitHub](https://github.com/poissonconsulting/chk)
```r
# install.packages("pak", repos = sprintf("https://r-lib.github.io/p/pak/stable/%s/%s/%s", .Platform$pkgType, R.Version()$os, R.Version()$arch))
pak::pak("poissonconsulting/chk")
```

## Demonstration

`chk` provides simple commonly used checks as (`chk_` functions) which can be combined together for more complex checking.

```{r, error = TRUE}
library(chk)

y <- "a"

chk_string(y)
chk_flag(y)

data <- data.frame(x = 1:2)
chk_range(nrow(data), c(3, 8))
```

Or used inside functions to test user-provided arguments.

```{r, error = TRUE}
my_fun <- function(x) {
  chk_flag(x)
  x
}
my_fun(TRUE)
my_fun(NA)
```

Error messages follow the [tidyverse style guide](https://style.tidyverse.org/error-messages.html) while the errors themselves are [rlang errors](https://rlang.r-lib.org/reference/abort.html) of class `chk_error`.

## Information

For more information see the [Get Started](https://poissonconsulting.github.io/chk/articles/chk.html) vignette.

## Inspiration

- [datacheckr](https://github.com/poissonconsulting/datacheckr/)
- [checkr](https://github.com/poissonconsulting/checkr/)
- [err](https://github.com/poissonconsulting/err/)
- [testthat](https://github.com/r-lib/testthat/)

## Contribution

Please report any [issues](https://github.com/poissonconsulting/chk/issues).

[Pull requests](https://github.com/poissonconsulting/chk/pulls) are always welcome.

## Code of Conduct

Please note that the chk project is released with a [Contributor Code of Conduct](https://contributor-covenant.org/version/2/0/CODE_OF_CONDUCT.html). By contributing to this project, you agree to abide by its terms.