如何使用 testthat 测试作为包一部分的独立 R 脚本

Question

I am building a R package, RE and I would like to package a standalone script with it to be placed in RE/exec/wrapper.R . I have written a test function for testthat which works just fine when run from the command line using devtools::test("RE") , but fails when run using devtools::check("RE") .

The relevant code portion that fails is:

cmd <- "Rscript \"C:\\RE\\exec\\wrapper.R\" base print \"{\\\"x\\\": 2}\""
rv <- system(cmd, intern = FALSE, ignore.stderr = FALSE, show.output.on.console = FALSE)

When run as part of "test" everything runs fine and system returns 0 as it should. When run as part of "check", system gives out the error message given below and returns 1 .

Error in file(filename, "r", encoding = encoding) : cannot open the connection
Calls: local ... eval.parent -> eval -> eval -> eval -> eval -> source -> file
In addition: Warning message:
In file(filename, "r", encoding = encoding) : cannot open file 'startup.Rs': No such file or directory
Execution halted

I have:

1. Checked that the file exists (it does in both cases)
2. Tried tryCatch . No error are caught, and system just returns a 1

This makes me think that it is an issue with system and R CMD CHECK .

Answer 1

The answer is in https://github.com/r-lib/testthat/issues/144 . The environment variable R_TESTS must be unset via Sys.setenv("R_TESTS" = "") in the top level test script ( package_root/tests/testthat.R ), or system will not run correctly when called from R CMD CHECK . I am leaving the question up, because it took me several hours of experimenting and searching before stumbling on the answer.