Mimic tools:::htmlify() (#2534)

Fixes #2530

NEWS.md

@@ -1,5 +1,6 @@
 # pkgdown (development version)
 
+* `build_reference()` now automatically translates `--`, `---`, ``` `` ```, and `''` to their unicode equivalents (#2530).
 * Tweaked navbar display on mobile so that long titles in drop downs (e.g. article titles) are now wrapped, and the search input spans the full width (#2512).
 * `build_reference()` now supports `\Sexpr[results=verbatim]` (@bastistician, #2510).
 * `build_home()` no longer checks if the README is missing any images. This check is now performed in `build_site()`, after `build_articles()` so you can refer to images created by vignettes with warnings (#2194).

R/rd-html.R

@@ -81,7 +81,16 @@ as_html.character <- function(x, ..., escape = TRUE) {
   }
 }
 #' @export
-as_html.TEXT <-  as_html.character
+as_html.TEXT <-  function(x, ..., escape = TRUE) { 
+  # tools:::htmlify
+  x <- gsub("---", "\u2014", x)
+  x <- gsub("--", "\u2013", x)
+  x <- gsub("``", "\u201c", x)
+  x <- gsub("''", "\u201d", x)
+
+  x <- as_html.character(x, ..., escape = escape)
+  x
+}
 #' @export
 as_html.RCODE <- as_html.character
 #' @export

tests/testthat/_snaps/rd-html.md

@@ -1,3 +1,10 @@
+# converts Rd unicode shortcuts
+
+    Code
+      rd2html("``a -- b --- c''")
+    Output
+      [1] "“a – b — c”"
+
 # subsection generates h3
 
     Code

tests/testthat/test-rd-html.R

@@ -3,6 +3,10 @@ test_that("special characters are escaped", {
   expect_equal(out, "a & b")
 })
 
+test_that("converts Rd unicode shortcuts", {
+  expect_snapshot(rd2html("``a -- b --- c''"))
+})
+
 test_that("simple tags translated to known good values", {
   # Simple insertions
   expect_equal(rd2html("\\ldots"), "...")