create_package checks you're not inside an existing project

* remove vcs from project consideration
* correct evaluation of force
* error if no project root found

Author: hadley

R/create.R

@@ -1,22 +1,28 @@
-#' Setup a complete package
+#' Create a package from scratch
+#'
+#' This changes the active project to the new package so that subsequent
+#' `use_` calls will affect the project that you've just created.
 #'
 #' @param path A path. If it exists, it will be used. If it does not
 #'   exist, it will be created (providing that the parent path exists).
 #' @param rstudio If `TRUE`, run [use_rstudio()].
 #' @param open If `TRUE`, will automatically open
 #' @inheritParams use_description
 #' @export
-create_package <- function(path,
+create_package <- function(path = ".",
                            fields = getOption("devtools.desc"),
                            rstudio = rstudioapi::isAvailable(),
                            open = interactive()) {
 
-  name <- basename(normalizePath(path, mustWork = FALSE))
+  path <- normalizePath(path, mustWork = FALSE)
+
+  name <- basename(path)
   check_package_name(name)
+  check_not_nested(dirname(path))
 
   create_directory(dirname(path), name)
   cat_line(crayon::bold("Changing active project to", crayon::red(name)))
-  proj_set(path)
+  proj_set(path, force = TRUE)
 
   use_directory("R")
   use_directory("man")
@@ -32,9 +38,32 @@ create_package <- function(path,
       project_path <- file.path(normalizePath(path), paste0(name, ".Rproj"))
       utils::browseURL(project_path)
     } else {
-      todo("Please change working directory to ", value(path))
+      setwd(path)
+      done("Changing working directory to ", value(path))
     }
   }
 
   invisible(TRUE)
 }
+
+check_not_nested <- function(path) {
+  proj_root <- proj_find(path)
+
+  if (is.null(proj_root))
+    return()
+
+  message <- paste0(
+    "Project is nested inside an existing project (", value(proj_root), ")"
+  )
+  if (!interactive()) {
+    stop(message, call. = FALSE)
+  }
+
+  cat_line(message)
+  cat_line("Creating a project inside another project is usually ill-advised.")
+
+  if (yesno("Do you wish to create anyway?")) {
+    stop(message, call. = FALSE)
+  }
+
+}

R/proj.R

@@ -1,44 +1,50 @@
 proj <- new.env(parent = emptyenv())
 
-proj_find <- function(path = ".") {
-  criteria <- rprojroot::has_file(".here") |
+proj_crit <- function() {
+  rprojroot::has_file(".here") |
     rprojroot::is_rstudio_project |
     rprojroot::is_r_package |
     rprojroot::is_remake_project |
-    rprojroot::is_projectile_project |
-    rprojroot::is_vcs_root
-
-  rprojroot::find_root(criteria, path = path)
+    rprojroot::is_projectile_project
 }
 
+proj_find <- function(path = ".") {
+  tryCatch(
+    rprojroot::find_root(proj_crit(), path = path),
+    error = function(e) NULL
+  )
+}
 
 #' Get and set currently active project
 #'
 #' When attached, usethis uses rprojroot to find the project root of the
 #' current working directory. It establishes the project root by looking for
 #' for a `.here` file, an RStudio project, a package `DESCRIPTION`, a
-#' `remake.yml`, `.projectile` file, or `.git`/`.svn` directories. It then
-#' stores the project directory for use for the remainder of the session.
-#' If needed, you can manually override by running `proj_set()`.
+#' `remake.yml`, or a `.projectile` file. It then stores the project directory
+#' for use for the remainder of the session. If needed, you can manually
+#' override by running `proj_set()`.
 #'
 #' @param path Path to set.
 #' @param force If `TRUE`, uses this path without checking if any parent
 #'   directories are existing projects.
 #' @keywords internal
 #' @export
 proj_get <- function() {
+  if (is.null(proj$cur)) {
+    stop("No active project found", call. = FALSE)
+  }
   proj$cur
 }
 
 #' @export
 #' @rdname proj_get
 proj_set <- function(path = ".", force = FALSE) {
-  old <- proj_get()
+  old <- proj$cur
 
   if (force) {
-    proj$cur <- proj_find(path)
-  } else {
     proj$cur <- path
+  } else {
+    proj$cur <- proj_find(path)
   }
 
   invisible(old)