homebrew an install prompt

Author: teunbrand

R/utilities.R

@@ -818,3 +818,32 @@ as_unordered_factor <- function(x) {
   class(x) <- setdiff(class(x), "ordered")
   x
 }
+
+# TODO: Replace me if rlang/#1730 gets implemented
+# Similar to `rlang::check_installed()` but returns boolean and misses
+# features such as versions, comparisons and using {pak}.
+prompt_install <- function(pkg, reason = NULL) {
+  if (length(pkg) < 1 || is_installed(pkg)) {
+    return(TRUE)
+  }
+  if (!interactive()) {
+    return(FALSE)
+  }
+
+  pkg <- pkg[!vapply(pkg, is_installed, logical(1))]
+
+  message <- "The {.pkg {pkg}} package{?s} {?is/are} required"
+  if (is.null(reason)) {
+    message <- paste0(message, ".")
+  } else {
+    message <- paste0(message, " ", reason)
+  }
+  question <- "Would you like to install {cli::qty(pkg)}{?it/them}?"
+
+  cli::cli_bullets(c("!" = message, "i" = question))
+  if (utils::menu(c("Yes", "No")) != 1) {
+    return(FALSE)
+  }
+  utils::install.packages(pkg)
+  is_installed(pkg)
+}