tests/testthat/test-5-try_fetch.R

In AzureML: Interface with Azure Machine Learning Datasets, Experiments and Web Services

if(interactive()) library(testthat)

context("try_fetch")
library(mockery)

test_that("try_fetch() gives exponential retry messages",{
  set.seed(1)
  mockery::stub(try_fetch, "curl_fetch_memory", function(...){
    retry_on = c(400, 401, 440, 503, 504, 509)
    status_code <- if(runif(1) > 0.26) sample(retry_on, 1) else 200
    list(status_code = status_code, contents = NA)
  })
  msg <- "Request failed with status 509. Waiting 0.0 seconds before retry\n"
  expect_message(
    try_fetch(delay = 0.1, no_message_threshold = 0),
    msg
  )
  
})