lintr: A 'Linter' for R Code

function_return_linter

R Documentation

Lint common mistakes/style issues cropping up from return statements

Description

return(x <- ...) is either distracting (because x is ignored), or confusing (because assigning to x has some side effect that is muddled by the dual-purpose expression).

Usage

function_return_linter()

Examples

# will produce lints
lint(
  text = "foo <- function(x) return(y <- x + 1)",
  linters = function_return_linter()
)

lint(
  text = "foo <- function(x) return(x <<- x + 1)",
  linters = function_return_linter()
)

writeLines("e <- new.env() \nfoo <- function(x) return(e$val <- x + 1)")
lint(
  text = "e <- new.env() \nfoo <- function(x) return(e$val <- x + 1)",
  linters = function_return_linter()
)

# okay
lint(
  text = "foo <- function(x) return(x + 1)",
  linters = function_return_linter()
)

code_lines <- "
foo <- function(x) {
  x <<- x + 1
  return(x)
}
"
lint(
  text = code_lines,
  linters = function_return_linter()
)

code_lines <- "
e <- new.env()
foo <- function(x) {
  e$val <- x + 1
  return(e$val)
}
"
writeLines(code_lines)
lint(
  text = code_lines,
  linters = function_return_linter()
)

r-lib/lintr documentation built on Dec. 20, 2024, 7:24 p.m.