init.R

# This file is executed with its containing directory as wd

# Remember the working directory (should be extension subfolder that contains this script)
dir_init <- getwd()


# This function is run at the beginning of R's startup sequence
# Code that is meant to be run at the end of the startup should go in `init_last`
init_first <- function() {
    # return early if not a vscode term session
    if (
        !interactive() ||
            Sys.getenv("RSTUDIO") != "" ||
            Sys.getenv("TERM_PROGRAM") != "vscode"
    ) {
        return()
    }

    # check required packages
    required_packages <- c("jsonlite", "rlang", "readr")
    missing_packages <- required_packages[
        !vapply(required_packages, requireNamespace,
            logical(1L),
            quietly = TRUE
        )
    ]

    if (length(missing_packages)) {
        message(
            "VSCode R Session Watcher requires ",
            toString(missing_packages), ". ",
            "Please install manually in order to use VSCode-R."
        )
    } else {
        # Initialize vsc utils after loading other default packages
        assign(".First.sys", init_last, envir = globalenv())
    }
}

old.First.sys <- .First.sys

# Overwrite for `.First.sys`
# Is used to make sure that all default packages are loaded first
# Will be assigned to and called from the global environment,
# Will be run with wd being the user's working directory (!)
init_last <- function() {
    old.First.sys()

    source(file.path(dir_init, "init_late.R"), chdir = TRUE)

    # remove this function from globalenv()
    suppressWarnings(
        rm(".First.sys", envir = globalenv())
    )

    invisible()
}

init_first()