R: Check that all dots have been used

check_dots_used {rlang} | R Documentation

## Check that all dots have been used

### Description

When `...` arguments are passed to methods, it is assumed there method will match and use these arguments. If this isn't the case, this often indicates a programming error. Call `check_dots_used()` to fail with an error when unused arguments are detected.

### Usage

    check_dots_used(
      env = caller_env(),
      call = caller_env(),
      error = NULL,
      action = deprecated()
    )

### Arguments

`env` | Environment in which to look for `...` and to set up handler.
`call` | The execution environment of a currently running function, e.g. `caller_env()`. The function will be mentioned in error messages as the source of the error. See the `call` argument of `abort()` for more information.
`error` | An optional error handler passed to `try_fetch()`. Use this e.g. to demote an error into a warning.
`action` |

### Details

In packages, document `...` with this standard tag:

     @inheritParams rlang::args_dots_used

`check_dots_used()` implicitly calls `on.exit()` to check that all elements of `...` have been used when the function exits. If you use `on.exit()` elsewhere in your function, make sure to use `add = TRUE` so that you don't override the handler set up by `check_dots_used()`.

### Examples

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

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

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

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

[Package rlang version 1.0.2 Index]