if (requireNamespace("box", quietly = TRUE)) {
    ## tests for with_script_path                               ----


    oscript_path <- box::script_path()
    this.path::with_script_path(box::script_path())
    ## the script_path must be restored to its original value
    stopifnot(identical(oscript_path, box::script_path()))


    ## check the namespace is never loaded if the user did not request it so
    unloadNamespace("box")
    stopifnot(!isNamespaceLoaded("box"))
    this.path::with_script_path(stopifnot(!isNamespaceLoaded("box")))
    stopifnot(!isNamespaceLoaded("box"))


    ## check the namespace hooks are not changed (except while in the function)
    hooks <- getHook(packageEvent("box"))
    this.path::with_script_path({
        stopifnot(length(hooks) + 1L == length(getHook(packageEvent("box"))))
        stopifnot(identical(hooks, getHook(packageEvent("box"))[seq_along(hooks)]))
    })
    stopifnot(identical(hooks, getHook(packageEvent("box"))))


    ## tests for "tests/package-box-supp/startsWith-NULL.R"     ----


    this.path::with_script_path(
    box::use(
        mod = ./`package-box-supp`/`startsWith-NULL`
    )
    )


    srcref <- attr(mod$fun_that_calls_src_path, "srcref")
    stopifnot(!is.null(srcref))
    srcfile <- attr(srcref, "srcfile")
    stopifnot(!is.null(srcfile))
    ## we expect the document context to not exist just yet
    stopifnot(is.null(srcfile[[".this.path::document.context"]]))


    namespace <- attr(mod, "namespace")
    stopifnot(!is.null(namespace))
    ## we expect the document context to not exist just yet
    stopifnot(is.null(attr(namespace, ".this.path::document.context")))


    mod$fun_that_calls_src_path(verbose = FALSE)
    doc_cntxt <- srcfile[[".this.path::document.context"]]
    ## now we do expect the document context to exist
    stopifnot(!is.null(doc_cntxt))
    ## we expect the source to be "path of srcfile"
    stopifnot(identical(
        as.character(list(doc_cntxt$source)),
        "path of srcfile"
    ))


    ## we expect the document context to still not exist
    stopifnot(is.null(attr(namespace, ".this.path::document.context")))


    mod$fun_that_calls_env_path(verbose = FALSE)
    doc_cntxt_2 <- attr(namespace, ".this.path::document.context")
    ## now we do expect the document context to exist
    stopifnot(!is.null(doc_cntxt_2))
    ## we expect the source to be "path of a 'package:box' namespace"
    stopifnot(identical(
        as.character(list(doc_cntxt_2$source)),
        "path of a 'package:box' namespace"
    ))


    ## we expect the contexts to not be equal
    stopifnot(!identical(doc_cntxt, doc_cntxt_2))


    box::unload(mod)


    ## tests for "tests/package-box-supp/startsWith-sys-path.R" ----


    this.path::with_script_path(
    box::use(
        mod = ./`package-box-supp`/`startsWith-sys-path`
    )
    )


    ## we expect the source to be
    ## "call to function 'load_from_source' from package 'box'"
    stopifnot(identical(
        as.character(list(mod$doc_cntxt$source)),
        "call to function 'load_from_source' from package 'box'"
    ))


    srcref <- attr(mod$fun_that_calls_src_path, "srcref")
    stopifnot(!is.null(srcref))
    srcfile <- attr(srcref, "srcfile")
    stopifnot(!is.null(srcfile))
    ## we expect the document context to be identical to that of sys.path()
    stopifnot(identical(mod$doc_cntxt, srcfile[[".this.path::document.context"]]))


    namespace <- attr(mod, "namespace")
    stopifnot(!is.null(namespace))
    ## we expect the document context to be identical to that of sys.path()
    stopifnot(identical(mod$doc_cntxt, attr(namespace, ".this.path::document.context")))


    box::unload(mod)


    ## tests for "tests/package-box-supp/startsWith-env-path.R" ----


    this.path::with_script_path(
    box::use(
        mod = ./`package-box-supp`/`startsWith-env-path`
    )
    )


    ## we expect the source to be "path of a 'package:box' namespace"
    stopifnot(identical(
        as.character(list(mod$doc_cntxt$source)),
        "path of a 'package:box' namespace"
    ))


    srcref <- attr(mod$fun_that_calls_src_path, "srcref")
    stopifnot(!is.null(srcref))
    srcfile <- attr(srcref, "srcfile")
    stopifnot(!is.null(srcfile))
    ## we expect the document context to be identical to that of env.path()
    stopifnot(identical(mod$doc_cntxt, srcfile[[".this.path::document.context"]]))


    namespace <- attr(mod, "namespace")
    stopifnot(!is.null(namespace))
    ## we expect the document context to be identical to that of env.path()
    stopifnot(identical(mod$doc_cntxt, attr(namespace, ".this.path::document.context")))


    box::unload(mod)


    ## tests for "tests/package-box-supp/startsWith-src-path.R" ----


    this.path::with_script_path(
    box::use(
        mod = ./`package-box-supp`/`startsWith-src-path`
    )
    )


    ## we expect the source to be "path of srcfile"
    stopifnot(identical(
        as.character(list(mod$doc_cntxt$source)),
        "path of srcfile"
    ))


    srcref <- attr(mod$fun_that_calls_src_path, "srcref")
    stopifnot(!is.null(srcref))
    srcfile <- attr(srcref, "srcfile")
    stopifnot(!is.null(srcfile))
    ## we expect the document context to be identical to that of src.path()
    stopifnot(identical(mod$doc_cntxt, srcfile[[".this.path::document.context"]]))


    namespace <- attr(mod, "namespace")
    stopifnot(!is.null(namespace))
    ## we expect the document context to be identical to that of src.path()
    stopifnot(identical(mod$doc_cntxt, attr(namespace, ".this.path::document.context")))


    box::unload(mod)
} else cat("\n'package:box' is not available :(\n")