Error in `file(con, "rb")`: cannot open the connection

testthat::test_that("`allele_counter()` works as expected", {
testthat::test_that("`cellranger()` works as expected", {
testthat::test_that("`fastq_pair()` works as expected", {
testthat::test_that("`gistic2()` works as expected", {
testthat::test_that("`kraken_tools()` works as expected", {
testthat::test_that("`kraken2()` works as expected", {
testthat::test_that("`perl()` works as expected", {
testthat::test_that("`python()` works as expected", {
testthat::test_that("`seqkit()` works as expected", {
testthat::test_that("`trust4()` works as expected", {
testthat::test_that("`pipe()` method works well", {

Error in `gzfile(file, open = "r")`: cannot open the connection

testthat::test_that("`read_lines()` workds as expected", {
gzip_file <- paste(file, "gz", sep = ".")
exec("gzip", "-c", file, ">", gzip_file)$run()
bzip2_file <- paste(file, "bz", sep = ".")
exec("gzip", "-c", file, ">", bzip2_file)$run()
exec("gzip", "-c", file, ">", xz_file)$run()