Merge pull request #1275 from r-lib/dev-roxygen-nested

more informative error message on nested dont statements in roxygen code examples

Author: lorenzwalthert

R/roxygen-examples-find.R

@@ -61,6 +61,17 @@ find_dont_seqs <- function(bare) {
 find_dont_closings <- function(bare, dont_openings) {
   opening <- cumsum(bare == "{")
   closing <- cumsum(bare == "}")
+  if (sum(closing) == 0L) {
+    rlang::abort(paste0(
+      "Failed to find closing braces for a \\dont* statement in a roxygen ",
+      "code example. This is most likely caused by nested \\donttest, ",
+      "\\dontrun or \\dontshow statement. These are not supported with ",
+      "{styler}, not even when {styler} is turned off for these lines as per ",
+      "the documentation at ",
+      "https://styler.r-lib.org/articles/styler.html#ignoring-certain-lines. ",
+      "See also GitHub issue https://github.com/r-lib/styler/issues/498."
+    ))
+  }
   diff <- opening - closing
   level_dont <- diff[dont_openings]
   match_closing <- intersect(

tests/testthat/test-roxygen-examples-parse.R

@@ -41,6 +41,19 @@ test_that("donts can be parsed", {
   )
 })
 
+test_that("Nested dont* statements return informative error message", {
+  expect_error(
+    style_roxygen_code_example_one(
+      c(
+        "#' @examples", "#' # styler: off", "#' \\donttest{", "#' \\dontshow{",
+        "#'   1+1", "#' }", "#' }", "#' # styler: on"
+      ),
+      transformers = tidyverse_style(scope = "spaces"), base_indention = 2L
+    ),
+    regexp = "nested \\\\donttest"
+  )
+})
+
 test_that("braces examples can be parsed", {
   expect_equal(
     parse_roxygen(