assert function

Assert truthfulness of conditions before evaluation

This function is a wrapper of stopifnot(), tryCatch() and cli::cli_abort() and asserts the truthfulness of the passed expression(s).

assert(..., error_message = NULL)

Arguments

• ...: expressions >= 1. If named the names are used as error messages, otherwise R's internal error-messages are thrown
• error_message: character. An error message, supports cli::cli -formatting.

Returns

NULL if all statements in ... are TRUE

Examples

## Not run:

  # script start;

  # 1) unnamed assert
  # expressions
  foo <- function(
    a,
    b) {

    # assert without
    # named expressions
    cryptoQuotes:::assert(
      is.numeric(a),
      is.numeric(b)
    )

    a + b

  }

  # 1.1) returns
  # the regular R error
  # messages in cli-format
  foo(
    a = "1",
    b = "2"
  )

  # 2) named assert
  # expressions
  foo <- function(
    a,
    b) {

    cryptoQuotes:::assert(
      "{.arg a} is not {.cls numeric}" =  is.numeric(a),
      "{.arg a} is not {.cls numeric}" = is.numeric(b)
    )

    a + b

  }

  # 2.2) Returns
  # custom error-messages
  # in cli-format
  foo(
    a = "1",
    b = "2"
  )

  # 3) custom error
  # messages on
  foo <- function(
    a) {

    cryptoQuotes:::assert(
      is.numeric(a),
      error_message = sprintf(
        fmt = "{.val %s} is not a numeric value.",
        a
      )
    )

    a

  }

  # 2.2) Returns
  # custom error-messages with
  # passed values in cli-format
  foo(
    a = "1"
  )

  # script end;
## End(Not run)

See Also

stopifnot(), cli::cli_abort(), tryCatch()