don't include the yaml component in the returned value of yaml_body…

…() if YAML metadata is not found in the input

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: xfun
 Type: Package
 Title: Supporting Functions for Packages Maintained by 'Yihui Xie'
-Version: 0.43.4
+Version: 0.43.5
 Authors@R: c(
   person("Yihui", "Xie", role = c("aut", "cre", "cph"), email = "[email protected]", comment = c(ORCID = "0000-0003-0645-5666")),
   person("Wush", "Wu", role = "ctb"),

R/yaml.R

@@ -118,19 +118,19 @@ yaml_handlers = function(h, envir) {
 #' @param x A character vector of the document content.
 #' @param ... Arguments to be passed to `yaml_load()`.
 #' @export
-#' @return A list of components `yaml` and `body`.
+#' @return A list of components `yaml` (if YAML metadata exists) and `body`.
 #' @examples
 #' xfun::yaml_body(c('---', 'title: Hello', 'output: markdown::html_document', '---', '', 'Content.'))
 yaml_body = function(x, ...) {
   i = grep('^---\\s*$', x)
   n = length(x)
   res = if (n < 2 || length(i) < 2 || (i[1] > 1 && !all(is_blank(x[seq(i[1] - 1)])))) {
-    list(yaml = list(), body = x)
+    list(body = x)
   } else list(
     yaml = x[i[1]:i[2]], body = c(rep('', i[2]), tail(x, n - i[2]))
   )
-  if ((n <- length(res$yaml)) >= 3) {
-    res$yaml = yaml_load(res$yaml[-c(1, n)], ...)
+  if ((n <- length(res$yaml)) >= 2) {
+    res['yaml'] = list(yaml_load(res$yaml[-c(1, n)], ...))
   }
   res
 }