respect knitr chunk headers for spinning.

Author: lorenzwalthert

R/expr-is.R

@@ -43,14 +43,32 @@ is_comment <- function(pd) {
 #' @examples
 #' style_text("#!/usr/bin/env Rscript")
 is_shebang <- function(pd) {
-  if (is.null(pd)) return(rep(FALSE, nrow(pd)))
   is_first_comment <- is_comment(pd) & (pd$pos_id == 1L)
   is_first_comment[is_first_comment] <- grepl(
     "^#!", pd$text[is_first_comment], perl = TRUE
   )
   is_first_comment
 }
 
+#' Identify spinning code chunk header
+#'
+#' See https://yihui.name/knitr/demo/stitch/#spin-comment-out-texts for details.
+#' @examples
+#' style_text(c(
+#'   "# title",
+#'   "some_code <- function() {}",
+#'   "#+ chunk-label, opt1=value1",
+#'   "call(3, 2, c(3:2))"
+#'   ))
+#' @param pd A parse table.
+is_code_chunk_header <- function(pd) {
+  is_comment <- is_comment(pd)
+  is_comment[is_comment] <- grepl(
+    "^#[\\+|\\-]", pd$text[is_comment], perl = TRUE
+  )
+  is_comment
+}
+
 contains_else_expr <- function(pd) {
   any(pd$token == "ELSE")
 }
@@ -74,7 +92,6 @@ contains_else_expr_that_needs_braces <- function(pd) {
   }
 }
 
-
 is_cond_expr <- function(pd) {
   pd$token[1] == "IF"
 }

R/rules-spacing.R

@@ -183,7 +183,7 @@ set_space_between_levels <- function(pd_flat) {
 #'   after the regex "^#+'*".
 #' @importFrom purrr map_chr
 start_comments_with_space <- function(pd, force_one = FALSE) {
-  comment_pos <- is_comment(pd) & !is_shebang(pd)
+  comment_pos <- is_comment(pd) & !is_shebang(pd) & !is_code_chunk_header(pd)
   if (!any(comment_pos)) return(pd)
 
   comments <- rematch2::re_match(

man/is_code_chunk_header.Rd

@@ -0,0 +1,11 @@
+#A comment
+a <- function() {
+
+}
+
+#+ chunk-label, opt1=value1
+"chunk-content"
+
+#- chunk-label, opt1=value1
+call(2, 3)
+#21

tests/testthat/parse_comments/spinning_code_chunk_headers-in.R

@@ -0,0 +1,11 @@
+# A comment
+a <- function() {
+
+}
+
+#+ chunk-label, opt1=value1
+"chunk-content"
+
+#- chunk-label, opt1=value1
+call(2, 3)
+# 21

tests/testthat/parse_comments/spinning_code_chunk_headers-in_tree

@@ -48,3 +48,9 @@ test_that("hashbangs are respected", {
                                  "shebang",
                                  transformer = style_text), NA)
 })
+
+test_that("code chunk headers for spinning are respected", {
+  expect_warning(test_collection("parse_comments",
+                                 "spinning_code_chunk_headers",
+                                 transformer = style_text), NA)
+})