R: Examples for 'rlang::check_dots

### ** Examples

f <- function(...) {
  check_dots_used()
  g(...)
}

g <- function(x, y, ...) {
  x + y
}
f(x = 1, y = 2)

[1] 3

try(f(x = 1, y = 2, z = 3))

Error in f(x = 1, y = 2, z = 3) : Arguments in `...` must be used.
✖ Problematic argument:
• z = 3
ℹ Did you misspell an argument name?

try(f(x = 1, y = 2, 3, 4, 5))

Error in f(x = 1, y = 2, 3, 4, 5) : Arguments in `...` must be used.
✖ Problematic arguments:
• ..1 = 3
• ..2 = 4
• ..3 = 5
ℹ Did you misspell an argument name?

# Use an `error` handler to handle the error differently.
# For instance to demote the error to a warning:
fn <- function(...) {
  check_dots_empty(
    error = function(cnd) {
      warning(cnd)
    }
  )
  "out"
}
fn()

[1] "out"

Examples for 'rlang::check_dots_used'

Check that all dots have been used