if_fail <- function(expr, fn) {
  withCallingHandlers(expr, expectation_failure = fn)
}

test_temp_file <- function(fileext = "", pattern = "test-file-",
                           envir = parent.frame(), create = TRUE) {
  tmp <- tempfile(pattern = pattern, fileext = fileext)
  if (identical(envir, .GlobalEnv)) {
    message("Temporary files will _not_ be cleaned up")
  } else {
    withr::defer(
      try(unlink(tmp, recursive = TRUE, force = TRUE), silent = TRUE),
      envir = envir)
  }
  if (create) {
    cat("", file = tmp)
    normalizePath(tmp)
  } else {
    tmp
  }
}

test_temp_dir <- function(pattern = "test-dir-", envir = parent.frame()) {
  tmp <- test_temp_file(pattern = pattern, envir = envir, create = FALSE)
  dir.create(tmp, recursive = TRUE, showWarnings = FALSE)
  normalizePath(tmp)
}

httpbin_url <- function() {
  "eu.httpbin.org"
}

is_offline <- (function() {
  offline <- NULL
  function() {
    if (is.null(offline)) {
      offline <<- tryCatch(
        is.na(pingr::ping_port(httpbin_url(), port = 443, count = 1L)),
        error = function(e) TRUE
      )
    }
    offline
  }
})()

skip_if_offline <- function() {
  skip_on_cran()
  if (is_offline()) skip("Offline")
}