close #2141: show the inline code in the error message, so that users…

… can find it more easily in the source document

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: knitr
 Type: Package
 Title: A General-Purpose Package for Dynamic Report Generation in R
-Version: 1.39.3
+Version: 1.39.4
 Authors@R: c(
     person("Yihui", "Xie", role = c("aut", "cre"), email = "xie@yihui.name", comment = c(ORCID = "0000-0003-0645-5666")),
     person("Abhraneel", "Sarma", role = "ctb"),

NEWS.md

@@ -2,6 +2,8 @@
 
 ## MINOR CHANGES
 
+- When the inline R code cannot be correctly parsed, the error message will show the original code in addition to the parsing error, which can make it easier to identify the code error in the source document (thanks, @AlbertLei, #2141).
+
 - The internal function `knitr:::wrap()` has been removed from this package. If you rely on this function, you will have to use the exported function `knitr::sew()` instead.
 
 - Duplicate chunk label error will now be thrown with code chunks using `code` or `file` chunk options (thanks, @mine-cetinkaya-rundel, #2126).

R/hooks.R

@@ -11,7 +11,9 @@
   message = .out.hook, error = .out.hook, plot = .plot.hook,
   inline = .inline.hook, chunk = .out.hook, text = identity,
   evaluate.inline = function(code, envir = knit_global()) {
-    v = withVisible(eval(parse_only(code), envir = envir))
+    v = withVisible(eval(tryCatch(parse_only(code), error = function(e) {
+      stop2('Failed to parse the inline R code: ', code, ' (Reason: ', e$message, ')')
+    }), envir = envir))
     if (v$visible) knit_print(v$value, inline = TRUE, options = opts_chunk$get())
   },
   evaluate = function(...) evaluate::evaluate(...), document = identity