context("wand can correctly test files") test_that("a sample image file is identified correctly", { tmp <- incant(list.files(system.file("extdata", "img", package="wand"), full.names=TRUE), magic_wand_file()) tmp <- tmp$description tmp <- unlist(tmp, use.names=FALSE) tmp <- sort(tmp) expect_that(any(substr(tmp, 1, 3) == "PNG"), equals(TRUE)) })