Merge pull request #229 from frictionlessdata/write_na_null

Encode null as NULL and NA as string

NEWS.md

@@ -2,6 +2,7 @@
 
 * [checklist](https://github.com/inbo/checklist) tooling was removed, in favour of `CITATION.cff` for citation and Zenodo deposit.
 * `write_package()` no longer writes to "." by default, since this is not allowed by CRAN policies. The user needs to explicitly define a directory (#205).
+* `write_package()` encodes NULL and NA values as NULL (#203).
 * `add_resource()` now allows to replace an existing resource (#227).
 
 # frictionless 1.1.0

R/write_package.R

@@ -74,7 +74,13 @@ write_package <- function(package, directory, compress = FALSE) {
 
   # Write datapackage.json
   package$directory <- NULL
-  package_json <- jsonlite::toJSON(package, pretty = TRUE, auto_unbox = TRUE)
+  package_json <- jsonlite::toJSON(
+    package,
+    pretty = TRUE,
+    null = "null",
+    na = "null",
+    auto_unbox = TRUE
+  )
   write(package_json, file.path(directory, "datapackage.json"))
 
   # Return (updated) package invisibly

tests/testthat/test-read_package.R

@@ -117,3 +117,10 @@ test_that("read_package() allows YAML descriptor", {
     check_package(read_package(test_path("data/valid_minimal.yml")))
   )
 })
+
+test_that("read_package() correctly converts a JSON `null` to an R NULL", {
+  p_path <- system.file("extdata", "datapackage.json", package = "frictionless")
+  p <- read_package(p_path)
+  # purrr::chuck() so an error is returned if `image` does not exist
+  expect_null(purrr::chuck(p, "image"))
+})

tests/testthat/test-write_package.R

@@ -327,3 +327,35 @@ test_that("write_package() will gzip file for compress = TRUE", {
   p_reread <- read_package(file.path(dir, "datapackage.json"))
   expect_identical(read_resource(p_reread, "new"), dplyr::as_tibble(df))
 })
+
+test_that("write_package() encodes null and NA as null", {
+  p <-
+    example_package %>%
+    add_resource(
+      resource_name = "new",
+      data = data.frame("col_1" = c(1, 2), "col_2" = c("a", "b")),
+      title = NA
+    )
+  # Set a custom property as NA, to see if it gets written as `null` in JSON
+  p$my_property <- NA
+
+  # Image is set as `NULL` in the JSON and that should still be the case here.
+  expect_null(purrr::chuck(p, "image"))
+
+  ## Use purrr::chuck() so an error is returned if image doesn't exist
+  expect_null(purrr::chuck(p, "image"))
+  expect_identical(p$resources[[4]]$title, NA)
+  expect_identical(p$my_property, NA)
+
+  dir <- file.path(tempdir(), "package")
+  on.exit(unlink(dir, recursive = TRUE))
+  write_package(p, dir)
+
+  p_loaded <- read_package(file.path(dir, "datapackage.json"))
+  # Use purrr::chuck() so an error is returned if the requested index doesn't
+  # exist
+  expect_null(purrr::chuck(p_loaded, "image"))
+  expect_null(purrr::chuck(p_loaded, "resources", 4, "title"))
+  ## my_property was set to NA, when writing this becomes NULL
+  expect_null(purrr::chuck(p_loaded, "my_property"))
+})