Add a better error for pin_versions() (#657)

* Add logic to trigger better error message

* Update tests

* Update snapshots

* Update NEWS

NEWS.md

@@ -1,5 +1,7 @@
 # pins (development version)
 
+* Improved error message for `pin_versions()` (#657).
+
 # pins 1.0.3
 
 * The `arrow` package is now suggested, rather than imported (#644, @jonthegeek).

R/pin_versions.R

@@ -38,7 +38,9 @@ pin_versions <- function(board, name, ..., full = deprecated()) {
     lifecycle::deprecate_warn("1.0.0", "pin_versions(full)")
   }
 
-  if (missing(name) || is.board(name) || name %in% board_list()) {
+  if (missing(name) && is.board(board)) {
+    abort("Argument `name` is missing, with no default")
+  } else if (missing(name) || is.board(name) || name %in% board_list()) {
     swap <- board
     board <- if (missing(name)) NULL else name
     board <- board_get(board)

tests/testthat/_snaps/pin_versions.md

@@ -5,14 +5,22 @@
       x <- pin_versions("x", "local")
       x <- pin_versions("x", board)
 
-# can't swap arguments with modern api
+# can't swap arguments or omit name with modern api
 
     Code
       pin_versions(name, board)
     Condition
       Error in `pin_versions()`:
       ! Please supply `board` then `name` when working with modern boards
 
+---
+
+    Code
+      pin_versions(board)
+    Condition
+      Error in `pin_versions()`:
+      ! Argument `name` is missing, with no default
+
 # `full` is deprecated
 
     Code

tests/testthat/test-pin_versions.R

@@ -10,10 +10,11 @@ test_that("can use old pin_versions() api", {
   })
 })
 
-test_that("can't swap arguments with modern api", {
+test_that("can't swap arguments or omit name with modern api", {
   board <- board_temp()
   name <- local_pin(board, 1)
   expect_snapshot(pin_versions(name, board), error = TRUE)
+  expect_snapshot(pin_versions(board), error = TRUE)
 })
 
 test_that("`full` is deprecated", {