interfacer (version 0.4.0)

ireturn: Validate and return a value from a function

Description

This is intended to be used within a function to check the validity of a data frame being returned from a function against the provided iface specification.

Usage

ireturn(df, iface, .prune = FALSE)

Value

a dataframe based on df with validity checks passed, data-types coerced, and correct grouping applied to conform to iface

Arguments

df

a dataframe - if missing then the first parameter of the calling function is assumed to be a dataframe.

iface

the interface specification that df should conform to.

.prune

get rid of excess columns that are not in the specification.

Details

As checks on output files can be unnecessary they are only run in certain circumstances:

interfacer::ireturn() checks run if:

• an option is set: options(interfacer.always_check=TRUE).

• we are locally developing a package and running functions in smoke testing e.g. with devtools::load_all().

• we are developing functions in the global environment.

• we are running functions in a testthat or R CMD check.

• we are running functions in a vignette during a R CMD check.

• we are running functions in a R markdown file (e.g. vignette) interactively in RStudio.

checks are not run if:

• package referencing interfacer::ireturn is installed from CRAN or r-universe

• package referencing interfacer::ireturn is installed locally using devtools::install

• vignette building directly using knitr (unless option is set in vignette).

• vignette building using pkgdown::build_site().

Examples

input = iface(col_in = integer ~ "an integer column" )
output = iface(col_out = integer ~ "an integer column" )

x = function(df = input, ...) {
  df = ivalidate(...)
  tmp = df %>% dplyr::rename(col_out = col_in)
  ireturn(tmp, output)
  stop("not executed as function has returned")
}
x(tibble::tibble(col_in = c(1,2,3)))
output