assertions (version 0.1.0)

assert_list: Assert input is a list

Description

Assert input is a list

Usage

assert_list(
  x,
  include_dataframes = FALSE,
  msg = NULL,
  call = rlang::caller_env(),
  arg_name = NULL
)

Value

invisible(TRUE) if x is a list, otherwise aborts with the error message specified by msg

Arguments

x

An object

include_dataframes

A logical indicating whether data_frames should be considered vectors. Default is FALSE.

msg

A character string containing the error message to display if x is not a list

call

Only relevant when pooling assertions into multi-assertion helper functions. See cli_abort for details.

arg_name

Advanced use only. Name of the argument passed (default: NULL, will automatically extract arg_name).

Examples

try({
# Assert that a variable is a list
x <- list(1, 2, 3)
assert_list(x)  # does nothing

# Assert that a variable is not a list
x <- "not a list"
assert_list(x)  # stops execution and prints an error message
})