Add use_import_from()

DESCRIPTION

@@ -50,6 +50,7 @@ Suggests:
     knitr,
     magick,
     mockr,
+    pkgload,
     rmarkdown,
     roxygen2,
     spelling (>= 1.2),

NAMESPACE

@@ -137,6 +137,7 @@ export(use_github_release)
 export(use_gitlab_ci)
 export(use_gpl3_license)
 export(use_gpl_license)
+export(use_import_from)
 export(use_jenkins)
 export(use_latest_dependencies)
 export(use_lgpl_license)

NEWS.md

@@ -9,6 +9,9 @@
 
 * `use_tidy_release_test_env()` has been deleted since we no longer recommend
   including test environment in CRAN comments (#1365).
+
+* Added `use_import_from()` to put `@importFrom pkg fun` into a package in a 
+  consistent way (@malcolmbarrett, #1377)
 
 # usethis 2.0.1
 

R/block.R

@@ -1,8 +1,12 @@
-block_append <- function(desc, value, path, block_start, block_end,
-                         block_prefix = NULL, block_suffix = NULL) {
+block_append <- function(desc, value, path,
+                         block_start = "# <<<",
+                         block_end = "# >>>",
+                         block_prefix = NULL,
+                         block_suffix = NULL,
+                         sort = FALSE) {
   if (!is.null(path) && file_exists(path)) {
     lines <- read_utf8(path)
-    if (value %in% lines) {
+    if (all(value %in% lines)) {
       return(FALSE)
     }
 
@@ -24,18 +28,24 @@ block_append <- function(desc, value, path, block_start, block_end,
   end <- block_lines[[2]]
   block <- lines[seq2(start, end)]
 
+  new_lines <- union(block, value)
+  if (sort) {
+    new_lines <- sort(new_lines)
+  }
+
   lines <- c(
     lines[seq2(1, start - 1L)],
-    block,
-    value,
+    new_lines,
     lines[seq2(end + 1L, length(lines))]
   )
   write_utf8(path, lines)
 
   TRUE
 }
 
-block_replace <- function(desc, value, path, block_start, block_end) {
+block_replace <- function(desc, value, path,
+                          block_start = "# <<<",
+                          block_end = "# >>>") {
   if (!is.null(path) && file_exists(path)) {
     lines <- read_utf8(path)
     block_lines <- block_find(lines, block_start, block_end)
@@ -68,13 +78,13 @@ block_replace <- function(desc, value, path, block_start, block_end) {
 }
 
 
-block_show <- function(path, block_start, block_end) {
+block_show <- function(path, block_start = "# <<<", block_end = "# >>>") {
   lines <- read_utf8(path)
   block <- block_find(lines, block_start, block_end)
   lines[seq2(block[[1]], block[[2]])]
 }
 
-block_find <- function(lines, block_start, block_end) {
+block_find <- function(lines, block_start = "# <<<", block_end = "# >>>") {
   # No file
   if (is.null(lines)) {
     return(NULL)
@@ -97,3 +107,7 @@ block_find <- function(lines, block_start, block_end) {
 
   c(start + 1L, end - 1L)
 }
+
+block_create <- function(lines = character(), block_start = "# <<<", block_end = "# >>>") {
+  c(block_start, unique(lines), block_end)
+}

R/pipe.R

@@ -25,12 +25,12 @@ use_pipe <- function(export = TRUE) {
   use_dependency("magrittr", "Imports")
 
   if (export) {
-    use_template("pipe.R", "R/utils-pipe.R") && roxygen_update()
+    use_template("pipe.R", "R/utils-pipe.R") && roxygen_remind()
     return(invisible(TRUE))
   }
 
   if (has_package_doc()) {
-    roxygen_ns_append("@importFrom magrittr %>%") && roxygen_update()
+    roxygen_ns_append("@importFrom magrittr %>%") && roxygen_remind()
     return(invisible(TRUE))
   }
 

R/rcpp.R

@@ -24,7 +24,7 @@ use_rcpp <- function(name = NULL) {
 
   use_dependency("Rcpp", "LinkingTo")
   use_dependency("Rcpp", "Imports")
-  roxygen_ns_append("@importFrom Rcpp sourceCpp") && roxygen_update()
+  roxygen_ns_append("@importFrom Rcpp sourceCpp") && roxygen_remind()
 
   use_src_example_script(name, "cpp")
 
@@ -55,7 +55,7 @@ use_rcpp_eigen <- function(name = NULL) {
 
   use_dependency("RcppEigen", "LinkingTo")
 
-  roxygen_ns_append("@import RcppEigen") && roxygen_update()
+  roxygen_ns_append("@import RcppEigen") && roxygen_remind()
 
   invisible()
 }
@@ -77,7 +77,7 @@ use_src <- function() {
   use_directory("src")
   use_git_ignore(c("*.o", "*.so", "*.dll"), "src")
   roxygen_ns_append(glue("@useDynLib {project_name()}, .registration = TRUE")) &&
-    roxygen_update()
+    roxygen_remind()
 
   invisible()
 }

R/roxygen.R

@@ -61,15 +61,30 @@ roxygen_ns_append <- function(tag) {
     path = proj_path(package_doc_path()),
     block_start = "## usethis namespace: start",
     block_end = "## usethis namespace: end",
-    block_suffix = "NULL"
+    block_suffix = "NULL",
+    sort = TRUE
+  )
+}
+roxygen_ns_show <- function(tag) {
+  block_show(
+    path = proj_path(package_doc_path()),
+    block_start = "## usethis namespace: start",
+    block_end = "## usethis namespace: end"
   )
 }
 
-roxygen_update <- function() {
+roxygen_remind <- function() {
   ui_todo("Run {ui_code('devtools::document()')} to update {ui_path('NAMESPACE')}")
   TRUE
 }
 
+roxygen_update_ns <- function() {
+  ui_done("Writing {ui_path('NAMESPACE')}")
+  utils::capture.output(
+    suppressMessages(roxygen2::roxygenise(proj_get(), "namespace"))
+  )
+  TRUE
+}
 
 # Checkers ----------------------------------------------------------------
 

R/tibble.R

@@ -32,7 +32,7 @@ use_tibble <- function() {
   check_uses_roxygen("use_tibble()")
 
   use_dependency("tibble", "Imports")
-  roxygen_ns_append("@importFrom tibble tibble") && roxygen_update()
+  roxygen_ns_append("@importFrom tibble tibble") && roxygen_remind()
 
   ui_todo("Document a returned tibble like so:")
   ui_code_block("#' @return a [tibble][tibble::tibble-package]", copy = FALSE)

R/use_import_from.R

@@ -0,0 +1,79 @@
+#' Import a function from another package
+#'
+#' @description
+#' `use_import_from()` imports a function from another package by adding the
+#' roxygen2 `@importFrom` tag to the package-level documentation (which can be
+#' created with [`use_package_doc()`]). Importing a function from another
+#' package allows you to refer to it without a namespace (e.g., `fun()` instead
+#' of `package::fun()`).
+#'
+#' `use_import_from()` also re-documents the NAMESPACE, and re-load the current
+#' package. This ensures that `fun` is immediately available in your development
+#' session.
+#'
+#' @param package Package name
+#' @param fun A vector of function names
+#' @param load Logical. Re-load with [`pkgload::load_all()`]?
+#' @return
+#' Invisibly, `TRUE` if the package document has changed, `FALSE` if not.
+#' @export
+#' @examples
+#' \dontrun{
+#' use_import_from("usethis", "ui_todo")
+#' }
+use_import_from <- function(package, fun, load = is_interactive()) {
+  if (!is_string(package)) {
+    ui_stop("{ui_code('package')} must be a single string")
+  }
+  check_is_package("use_import_from()")
+  check_uses_roxygen("use_import_from()")
+
+  if (!check_has_package_doc()) {
+    return(invisible(FALSE))
+  }
+  purrr::walk2(package, fun, check_fun_exists)
+
+  use_dependency(package, "Imports")
+  changed <- roxygen_ns_append(glue("@importFrom {package} {fun}"))
+
+  if (changed) {
+    roxygen_update_ns()
+
+    if (load) {
+      ui_done("Loading {project_name()}")
+      pkgload::load_all(quiet = TRUE)
+    }
+  }
+
+  invisible(changed)
+}
+
+check_fun_exists <- function(package, fun) {
+  if (exists(fun, envir = asNamespace(package))) {
+    return()
+  }
+  name <- paste0(package, "::", fun, "()")
+  ui_stop("Can't find {ui_code(name)}")
+}
+
+check_has_package_doc <- function() {
+  if (has_package_doc()) {
+    return(invisible(TRUE))
+  }
+
+  if (!is_interactive()) {
+    return(invisible(FALSE))
+  }
+
+  if (ui_yeah("
+    {ui_code('use_import_from()')} requires \\
+    package-level documentation. Would you like to add \\
+    it now?")) {
+    use_package_doc()
+  } else {
+    ui_todo("Run {ui_code('use_package_doc()')}")
+    return(invisible(FALSE))
+  }
+
+  invisible(TRUE)
+}

R/usethis-package.R

@@ -5,8 +5,6 @@
 #' @import rlang
 "_PACKAGE"
 
-# The following block is used by usethis to automatically manage
-# roxygen namespace tags. Modify with care!
 ## usethis namespace: start
 #' @importFrom lifecycle deprecated
 ## usethis namespace: end

inst/templates/packagename-package.R

@@ -1,8 +1,6 @@
 #' @keywords internal
 "_PACKAGE"
 
-# The following block is used by usethis to automatically manage
-# roxygen namespace tags. Modify with care!
 ## usethis namespace: start
 ## usethis namespace: end
 NULL

tests/testthat/_snaps/use_import_from.md

@@ -0,0 +1,23 @@
+# use_import_from() adds one line for each function
+
+    Code
+      roxygen_ns_show()
+    Output
+      [1] "#' @importFrom tibble deframe" "#' @importFrom tibble enframe"
+      [3] "#' @importFrom tibble tibble" 
+
+# use_import_from() generates helpful errors
+
+    Code
+      use_import_from(1)
+    Error <usethis_error>
+      `package` must be a single string
+    Code
+      use_import_from(c("tibble", "rlang"))
+    Error <usethis_error>
+      `package` must be a single string
+    Code
+      use_import_from("tibble", "pool_noodle")
+    Error <usethis_error>
+      Can't find `tibble::pool_noodle()`
+

tests/testthat/test-block.R

@@ -0,0 +1,18 @@
+test_that("block_append() only writes unique lines", {
+
+  path <- withr::local_tempfile()
+  writeLines(block_create(), path)
+
+  block_append("---", c("x", "y"), path)
+  block_append("---", c("y", "x"), path)
+  expect_equal(block_show(path), c("x", "y"))
+})
+
+test_that("block_append() can sort, if requested", {
+  path <- withr::local_tempfile()
+  writeLines(block_create(), path)
+
+  block_append("---", c("z", "y"), path)
+  block_append("---", "x", path, sort = TRUE)
+  expect_equal(block_show(path), c("x", "y", "z"))
+})

tests/testthat/test-use_import_from.R

@@ -0,0 +1,28 @@
+test_that("use_import_from() imports the related package & adds line to package doc", {
+  create_local_package()
+  use_package_doc()
+  use_import_from("tibble", "tibble")
+
+  expect_equal(trimws(desc::desc_get("Imports", proj_get()))[[1]], "tibble")
+  expect_equal(roxygen_ns_show(), "#' @importFrom tibble tibble")
+})
+
+test_that("use_import_from() adds one line for each function", {
+  create_local_package()
+  use_package_doc()
+  use_import_from("tibble", c("tibble", "enframe", "deframe"))
+
+  expect_snapshot(roxygen_ns_show())
+})
+
+test_that("use_import_from() generates helpful errors", {
+  create_local_package()
+  use_package_doc()
+
+  expect_snapshot(error = TRUE, {
+    use_import_from(1)
+    use_import_from(c("tibble", "rlang"))
+
+    use_import_from("tibble", "pool_noodle")
+  })
+})