add installation predicates

DESCRIPTION

@@ -40,3 +40,10 @@ Suggests:
 Config/testthat/edition: 3
 Config/testthat/parallel: true
 Config/Needs/website: rmarkdown
+Collate: 
+    'dependencies.R'
+    'elf-package.R'
+    'examples.R'
+    'tests.R'
+    'installed.R'
+    'options.R'

NAMESPACE

@@ -1,8 +1,15 @@
 # Generated by roxygen2: do not edit by hand
 
+export(assert_pkg_installed)
+export(check_pkg_installed)
+export(expect_pkg_installed)
 export(is_installed2)
 export(make_skip_if_not_function)
 export(opt_set_local2)
+export(skip_if_pkg_not_installed2)
 export(source_pef)
+export(test_pkg_installed)
 export(transform_with_generated)
 export(use_ex_file)
+importFrom(checkmate,makeExpectation)
+importFrom(checkmate,vname)

R/elf-package.R

@@ -2,5 +2,7 @@
 "_PACKAGE"
 
 ## usethis namespace: start
+#' @importFrom checkmate makeExpectation
+#' @importFrom checkmate vname
 ## usethis namespace: end
 NULL

R/installed.R

@@ -23,13 +23,45 @@ check_pkg_installed <- function(x = character(1L)) {
 }
 
 #' @describeIn pkg_installed returns `x` invisibly or errors out.
+#' @inheritParams checkmate::makeAssertion
+#' @inheritParams checkmate::assert
 #' @export
 assert_pkg_installed <- checkmate::makeAssertionFunction(check_pkg_installed)
 
 #' @describeIn pkg_installed returns `TRUE` or `FALSE`
+#' @inheritParams checkmate::makeTest
 #' @export
 test_pkg_installed <- checkmate::makeTestFunction(check_pkg_installed)
 
 #' @describeIn pkg_installed returns an [testthat::expectation()]
+#' @inheritParams checkmate::makeExpectation
 #' @export
 expect_pkg_installed <- checkmate::makeExpectationFunction(check_pkg_installed)
+
+#' @describeIn pkg_installed
+#' skips test if package is *not* installed.
+#' Same as [testthat::skip_if_not_installed()],
+#' except using [rlang::is_installed()] under the hood.
+#' @include tests.R
+#' @export
+skip_if_pkg_not_installed2 <- make_skip_if_not_function(check_pkg_installed)
+
+# installed but not via load_all ====
+
+#' Check if a package is installed, but not via [pkgload::load_all()]
+#'
+#' To speed up development,
+#' [pkgload::load_all()] simulates installing a package.
+#' This simulation is usually sufficient,
+#' but there are edge cases which it cannot cover.
+#' Use this family of predicates to guard against these edge cases.
+#'
+#' @details
+#' A frequent example of an edge case for [pkgload::load_all()]
+#' occurs when child processes are launched during development,
+#' such as in [shinytest2](https://rstudio.github.io/shinytest2/).
+#' These child processes may not "know" that their parent
+#' used the `load_all()`d version of an in-development package,
+#' but may instead use whichever version was last installed.
+#' This can lead to inconsistent results and painful confusion.
+#' @noRd

R/tests.R

@@ -23,7 +23,6 @@ transform_with_generated <- function(x = character()) {
 #' [checkmate](https://mllg.github.io/checkmate/index.html)'s
 #' `check_*()`-type functions into [testthat](https://testthat.r-lib.org)'s
 #' `skip_if_not_*()` functions.
-#'
 #' @inheritParams checkmate::makeAssertionFunction
 #' @details
 #' Notice that `check_*()` are always formulated *positively*;