Report top-level executable code in an R directory

Parses every .R file in dir and reports any top-level expression that is not an assignment. Function definitions and constants pass; calls do not.

Use this on any directory that is sourced wholesale, where a stray call would execute on every render.

Usage

r_dir_impurities(dir)

Arguments

dir

Character(1). Directory to check.

Value

A character vector of complaints, one per offending expression, empty when the directory is clean. The caller decides whether to warn or to fail.

Examples

d <- file.path(tempdir(), "purity-example")
dir.create(d, showWarnings = FALSE)
writeLines(c("f <- function(x) x + 1", "print(f(1))"),
           file.path(d, "example.R"))
r_dir_impurities(d)
#> [1] "example.R: top-level expression is not an assignment: print(f(1))"
unlink(d, recursive = TRUE)