Diagnose Suggested Packages Used in Examples Without a Guard — lab_suggested_in

Under CRAN's noSuggests check a package must work without its Suggested packages installed. This flags an example that needs a Suggested package, through pkg::, library() or require(), in code that runs without a guard naming that package: an enclosing if (requireNamespace("pkg", quietly = TRUE)) or if (require("pkg")), including roxygen's @examplesIf with one of them. rlang::is_installed("pkg") counts too, but it needs rlang, so it is a use of rlang when rlang is only suggested.

Usage

lab_suggested_in_examples(path = ".", verbose = TRUE)

Arguments

path: Character. Path to package directory
verbose: Logical. Print diagnostic messages

Value

checktor_check_result() with passed, issues, message.

Details

The example is read as parsed R, so a package named in a comment or a string is not a use, and a guard in a comment, a guard for another package, or one that does not enclose the use excuses nothing. Usage inside \dontrun{} is not flagged, since it never runs. Usage inside \donttest{} is, since R CMD check --as-cran runs it. A condition that is false under R CMD check keeps the use out of the check as surely as \dontrun{} does, so interactive(), identical(Sys.getenv("IN_PKGDOWN"), "true"), nzchar(Sys.getenv("IN_PKGDOWN")) and a test that NOT_CRAN is "true" excuse it too. A bare as.logical(Sys.getenv("NOT_CRAN")) does not: it is NA there, and if (NA) stops the example with an error. R's base packages, such as parallel and tools, and its recommended packages, such as MASS, Matrix and survival, ship with R and are never flagged.

Source

Writing R Extensions, under "Suggested packages", asks that a package from Suggests used in an example be guarded so the example still runs without it. See vignette("check-sources", package = "checktor") for how every check maps to its source.

Examples

pkg <- example_diagnose_scenario("documentation_examples/suggested_in_examples_bad.Rd",
                                 show_content = FALSE)
cat("Suggests: somesuggest\n",
    file = file.path(pkg, "DESCRIPTION"), append = TRUE)
lab_suggested_in_examples(pkg, verbose = FALSE)$issues
#> [1] "suggested_in_examples_bad.Rd: uses Suggested package 'somesuggest' in \\examples without a guard"
unlink(pkg, recursive = TRUE)