Merge pull request #554 from r-lib/b-551-quote-newlines

- Fix handling of newlines when converting quotes (#551).

Author: lorenzwalthert

NAMESPACE

@@ -34,6 +34,7 @@ importFrom(purrr,pwalk)
 importFrom(purrr,reduce)
 importFrom(purrr,when)
 importFrom(rlang,abort)
+importFrom(rlang,is_empty)
 importFrom(rlang,is_installed)
 importFrom(rlang,seq2)
 importFrom(rlang,warn)

NEWS.md

@@ -33,6 +33,9 @@
 
 * Escape characters in roxygen code examples are now correctly escaped (#512).
 
+* Special characters such as `\n` in strings are now preseved in text and not 
+  turned into literal values like a line break (#554).
+
 * Style selection Addin now preserves line break when the last line selected is
   an entire line (#520).
 

R/rules-spacing.R

@@ -126,16 +126,34 @@ remove_space_after_unary_pm_nested <- function(pd) {
 #' '")
 #' @importFrom purrr map map_chr
 #' @param pd_flat A flat parse table.
+#' @importFrom rlang is_empty
 #' @keywords internal
 fix_quotes <- function(pd_flat) {
-  str_const <- pd_flat$token == "STR_CONST"
-  str_const_change <- grepl("^'([^\"]*)'$", pd_flat$text[str_const])
-  pd_flat$text[str_const][str_const_change] <-
-    map(pd_flat$text[str_const][str_const_change], parse_text) %>%
-    map_chr(~ paste0("\"", .x, "\""))
+  str_const <- which(pd_flat$token == "STR_CONST")
+  if (is_empty(str_const)) {
+    return(pd_flat)
+  }
+
+  pd_flat$text[str_const] <- map(pd_flat$text[str_const], fix_quotes_one)
   pd_flat
 }
 
+#' @importFrom rlang is_empty
+fix_quotes_one <- function(x) {
+  rx <- "^'([^\"]*)'$"
+  i <- grep(rx, x)
+  if (is_empty(i)) {
+    return(x)
+  }
+
+  # replace outer single quotes
+  xi <- gsub(rx, '"\\1"', x[i])
+
+  # Replace inner escaped quotes (\') by ' and keep all other instances of \., including \\
+  x[i] <- gsub("\\\\(')|(\\\\[^'])", "\\1\\2", xi)
+  x
+}
+
 remove_space_before_opening_paren <- function(pd_flat) {
   paren_after <- pd_flat$token == "'('"
   if (!any(paren_after)) {

tests/testthat/escaping/basic-escape-in.R

@@ -22,6 +22,17 @@ NULL
 #' things
 #'
 #' @examples
-#' call('\n') # FIXME when single quotes are used, the newline is evaluated
+#' call('\n')
 #' ano("\\.", further = X)
 NULL
+
+'single quotes with
+embedded and \n not embedded line breaks'
+
+x <- '	2' # there is a tab emebbed (created with writeLines("x <- '\t2'"))
+
+x <- '\001'
+'\x01'
+
+# FIXME: "\01" gives an error when not in a comment
+# FIXME: this too: '\01'

tests/testthat/escaping/basic-escape-in_tree

@@ -22,7 +22,17 @@ NULL
 #' things
 #'
 #' @examples
-#' call("
-#' ") # FIXME when single quotes are used, the newline is evaluated
+#' call("\n")
 #' ano("\\.", further = X)
 NULL
+
+"single quotes with
+embedded and \n not embedded line breaks"
+
+x <- "	2" # there is a tab emebbed (created with writeLines("x <- '\t2'"))
+
+x <- "\001"
+"\x01"
+
+# FIXME: "\01" gives an error when not in a comment
+# FIXME: this too: '\01'

tests/testthat/escaping/basic-escape-out.R

@@ -13,7 +13,13 @@ test <- function() {
   single quotes are used
   .'
 
-  'strings with embeded\nline breaks are unfortunately split'
+  'strings with embedded\nline breaks are handled correctly'
+
+  '\\'
+  '\\\''
+  '\\\\'
+  '\\\\\''
+  '\'\\\\\''
 
   # Comments are always preserved