test_that("export writes data, coverage and a provenance sidecar", {
  dir <- tempfile("export")
  dir.create(dir)
  on.exit(unlink(dir, recursive = TRUE))
  path <- file.path(dir, "met.csv")
  x <- btg_get_data(force = c("metropolitan", "kent"))
  files <- btg_export(x, path)
  expect_setequal(basename(files), c("met.csv", "met.json", "met-coverage.csv"))
  expect_true(all(file.exists(files)))
  back <- utils::read.csv(path, stringsAsFactors = FALSE)
  expect_equal(nrow(back), 2)
  expect_equal(back$ratio, x$data$ratio)
  cov <- utils::read.csv(file.path(dir, "met-coverage.csv"), stringsAsFactors = FALSE)
  expect_equal(nrow(cov), 24)
  prov <- jsonlite::read_json(file.path(dir, "met.json"), simplifyVector = TRUE)
  expect_equal(prov$release, x$metadata$release)
  expect_equal(prov$payload_sha256$data, x$metadata$files$data$sha256)
  expect_equal(prov$selection$force, c("kent", "metropolitan"))
  expect_equal(prov$rows, 2)
  expect_match(prov$citation, "Open Government Licence")
  expect_error(btg_export(x, path), "File exists")
  expect_silent(btg_export(x, path, overwrite = TRUE))
  national <- btg_export(btg_get_data("national_year"), file.path(dir, "national.csv"))
  expect_length(national, 2)
  prov <- jsonlite::read_json(file.path(dir, "national.json"), simplifyVector = TRUE)
  expect_null(prov$payload_sha256$coverage)
  expect_error(btg_export(x, file.path(dir, "met.txt")), "end in .csv")
  expect_error(btg_export(x$data, path), "documented dataset")
})

test_that("the glossary defines the package's terms", {
  g <- btg_glossary()
  expect_true(all(c("ratio", "allocation range", "eligible", "rank", "coverage", "release", "saved view") %in% g$term))
  expect_false(anyDuplicated(g$term) > 0)
  expect_true(all(nchar(g$definition) > 40))
})