Merge pull request #634 from lorenzwalthert/issue-633

- Allow for dry run (#634).

Author: lorenzwalthert

NEWS.md

@@ -4,6 +4,8 @@
 
 - blank lines in function calls and headers are now removed, for the former only 
   when there are no comments before or after the blank line (#629, #630, #635).
+- `style_file()` and friends gain argument `dry` to control if changes should 
+  be applied to files or not (#634).
 
 ## Minor chnages and fixes
 

R/io.R

@@ -33,7 +33,10 @@ transform_utf8_one <- function(path, fun, dry) {
       if (!identical) {
         if (dry == "fail") {
           rlang::abort(
-            paste0("File `", path, "` would be modified by styler and `dry` = 'fail'."),
+            paste0(
+              "File `", path, "` would be modified by styler and argument dry",
+              " is set to 'fail'."
+            ),
             class = "dryError"
           )
         } else if (dry == "on") {

R/ui-styling.R

@@ -22,8 +22,8 @@ NULL
 #' @inheritParams prettify_pkg
 #' @section Warning:
 #' This function overwrites files (if styling results in a change of the
-#' code to be formatted). It is strongly suggested to only style files
-#' that are under version control or to create a backup copy.
+#' code to be formatted and `dry = "off"`). It is strongly suggested to only
+#' style files that are under version control or to create a backup copy.
 #'
 #' We suggest to first style with `scope < "tokens"` and inspect and commit
 #' changes, because these changes are guaranteed to leave the abstract syntax