close #98: add a message to remind users of calling pkg_code() in the package source dir

Author: yihui

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: litedown
 Type: Package
 Title: A Lightweight Version of R Markdown
-Version: 0.7.6
+Version: 0.7.7
 Authors@R: c(
     person("Yihui", "Xie", role = c("aut", "cre"), email = "[email protected]", comment = c(ORCID = "0000-0003-0645-5666", URL = "https://yihui.org")),
     person("Tim", "Taylor", role = "ctb", comment = c(ORCID = "0000-0002-8587-7113")),
@@ -21,8 +21,8 @@ Description: Render R Markdown to Markdown (without using 'knitr'), and Markdown
 Depends: R (>= 3.2.0)
 Imports:
     utils,
-    commonmark (>= 1.9.5),
-    xfun (>= 0.52)
+    commonmark (>= 2.0.0),
+    xfun (>= 0.54)
 Suggests:
     rbibutils,
     rstudioapi,

R/package.R

@@ -255,7 +255,10 @@ pkg_code = function(
   path = attr(detect_pkg(), 'path'), pattern = '[.](R|c|h|f|cpp)$', toc = TRUE,
   number_sections = TRUE, link = TRUE
 ) {
-  if (!isTRUE(dir.exists(path))) return()
+  if (!isTRUE(dir.exists(path))) {
+    if (missing(path)) message('Please run this function in the package source directory.')
+    return()
+  }
   a = header_class(toc, number_sections)
   if (isTRUE(link) && length(u <- github_link(path))) link = paste0(u, 'blob/HEAD/%s')
   ds = c('R', 'src')