Compression infrastructure is insufficiently tested

[chainsawriot]

rio/tests/testthat/test_compress.R

Lines 3 to 27 in 81c0423

	test_that("Recognize compressed file types", {
	expect_true(rio:::find_compress("file.zip")$compress == "zip")
	expect_true(rio:::find_compress("file.tar")$compress == "tar")
	expect_true(rio:::find_compress("file.tar.gz")$compress == "tar")
	expect_true(is.na(rio:::find_compress("file.gz")$compress))
	expect_true(is.na(rio:::find_compress("file.notcompressed")$compress))
	})
	test_that("Export to compressed (zip)", {
	e1 <- export(iris, "iris.csv.zip")
	expect_true(e1 %in% dir())
	})
	test_that("Export to compressed (tar)", {
	e2 <- export(iris, "iris.csv.tar")
	expect_true(e2 %in% dir())
	})
	test_that("Import from compressed", {
	expect_true(is.data.frame(import("iris.csv.zip")))
	expect_true(is.data.frame(import("iris.csv.zip", which = 1)))
	expect_true(is.data.frame(import("iris.csv.zip", which = "iris.csv")))
	# tar export does not work due to: https://bugs.r-project.org/bugzilla3/show_bug.cgi?id=16716
	#expect_true(is.data.frame(import("iris.csv.tar")))
	})

rio/R/compression.R

Line 18 in 81c0423

compress_out <- function(cfile, filename, type = c("zip", "tar", "gzip", "bzip2", "xz")) {

It only tests zip and tar. gzip (implemented in #123 ) is untested.

rio/R/import.R

Lines 112 to 116 in 81c0423

	if (missing(format)) {
	fmt <- get_ext(file)
	if (fmt %in% c("gz", "gzip")) {
	fmt <- tools::file_ext(tools::file_path_sans_ext(file, compression = FALSE))
	file <- gzfile(file)

So do formats such as xz and bzip2.

[chainsawriot]

TODO

• test bzip I and O
• test xz I and O

[chainsawriot]

After #380, it is pretty easy to implement this.

rio/tests/testthat/test_compress.R

Lines 11 to 21 in 479a765

	test_that("Export to compressed (zip) / import", {
	withr::with_tempfile("iris_path", fileext = ".csv.zip", code = {
	e1 <- export(iris, iris_path)
	expect_true(file.exists(iris_path))
	expect_true(is.data.frame(import(iris_path)))
	expect_true(is.data.frame(import(iris_path)))
	expect_true(is.data.frame(import(iris_path, which = 1)))
	base_file_name <- gsub("\\.zip", "", basename(iris_path))
	expect_true(is.data.frame(import(iris_path, which = base_file_name)))
	})
	})