expect_condition()

[lionel-]

expect_condition <- function(expr,
                             class = NULL,
                             regex = NULL,
                             ...,
                             info = NULL,
                             label = NULL) {
  object <- tryCatch(expr, condition = identity)

  if (is_na(class)) {
    expect_false(inherits(object, "condition"), info = info, label = label)
    return(invisible(object))
  }

  expect_is(object, "condition", info = info, label = label)

  if (!is_null(class)) {
    expect_is(object, class, info = info, label = label)
  }
  if (!is_null(regex)) {
    expect_match(object$message, regex, ..., info = info, label = label)
  }

  invisible(object)
}

[hadley]

Should use the same basic approach for expect_error().

It's a bit painful to implement because each expect_ function should only call expect() once, and there's currently no great way to compose multiple expectations.

[hadley]

The main challenge here is that these expectations call expect_match() and it's not readily composable. I think pull out a common lower-level line comparison function will help (and will also improve the error messages).