tests/testthat/test-well-formed-dois.R

In bgcarlisle/trn2doi: A data set of Trial Registration Numbers (TRNs) matched to Digital Object Identifiers (DOIs) for their primary results publications

test_that("All DOI's are well-formed", {
    expect_equal(
        sum(
            ! grepl(
                  "^10.\\d{4,9}/[-._;()/:A-Z0-9]+$",
                  lookup$doi,
                  ignore.case=TRUE
              )
        ),
        0
    )
})