tests/testthat/test-vegaspec.R

In vegawidget/vegawidget: 'Htmlwidget' for 'Vega' and 'Vega-Lite'

test_that("as_vegaspec translates", {

  # need to go to json and back because of data-frame in vw_ex_mtcars
  spec_ref <- spec_mtcars %>% vw_as_json() %>% as_vegaspec()
  spec_json <- vw_as_json(spec_ref)

  expect_identical(as_vegaspec(spec_ref), spec_ref)
  expect_identical(as_vegaspec(spec_json), spec_ref)

})

test_that("class is correct", {

  expect_type(as_vegaspec(unclass(spec_mtcars)), "list")
  expect_s3_class(as_vegaspec(unclass(spec_mtcars)), "vegaspec")
  expect_s3_class(as_vegaspec(unclass(spec_mtcars)), "vegaspec_vega_lite")

  spec_mtcars_vega <- vw_to_vega(spec_mtcars)

  expect_type(spec_mtcars_vega, "list")
  expect_s3_class(spec_mtcars_vega, "vegaspec")
  expect_s3_class(spec_mtcars_vega, "vegaspec_vega")

})

test_that("vw_as_json handles NULLS", {

  spec_test <- list(
    `$schema` = "https://vega.github.io/schema/vega-lite/v2.json",
    width = NULL,
    height = NULL
  )

  spec_test_json <- vw_as_json(spec_test)

  expect_match(spec_test_json, '"width": null')
  expect_match(spec_test_json, '"height": null')

})

test_that("vegaspec without $schema warns and adds element", {

  spec_test <- list()

  # warning
  expect_warning(
    spec_ref <- as_vegaspec(spec_test)
  )

  # check result
  expect_identical(
    spec_ref,
    as_vegaspec(list(`$schema` = vega_schema()))
  )

})

test_that("as_vegaspec reads UTF-8 correctly", {

  filename <- "test_encoding_utf8.vl4.json"
  description <- "ceci une version allégée d'une spécification vega-lite"

  # cleans up file
  withr::local_file(filename)

  fileConn <- file(filename, encoding = "UTF-8")
  writeLines(
    glue_js(
      "{",
      "  \"$schema\": \"https://vega.github.io/schema/vega-lite/v4.json\",",
      "  \"description\": \"${description}\"",
      "}"
    ),
    fileConn
  )
  close(fileConn)

  myspec <- vegawidget::as_vegaspec(filename)

  expect_identical(myspec$description, description)

})

test_that("as_vegaspec reads urls correctly", {

  skip_on_cran()

  myspec <- as_vegaspec("https://raw.githubusercontent.com/vega/vega-lite/next/examples/specs/bar.vl.json")

  expect_s3_class(myspec, "vegaspec_vega_lite")

})