make spin() work again with input that can't be parsed as R code

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: knitr
 Type: Package
 Title: A General-Purpose Package for Dynamic Report Generation in R
-Version: 1.45.16
+Version: 1.45.17
 Authors@R: c(
     person("Yihui", "Xie", role = c("aut", "cre"), email = "[email protected]", comment = c(ORCID = "0000-0003-0645-5666")),
     person("Abhraneel", "Sarma", role = "ctb"),

NEWS.md

@@ -14,6 +14,8 @@
 
 ## BUG FIXES
 
+- `spin()` stopped working with input that cannot be parsed as R code due to #1605. Now it works again (thanks, @Hemken, #1773).
+
 - `write_bib()` generated empty entries for packages without URLs (thanks, @bastistician, #2304).
 
 - The `family` argument was not passed to the `pdf` device (thanks, @sebkopf, rstudio/rmarkdown#2526).

R/spin.R

@@ -66,17 +66,24 @@ spin = function(
 
   # remove multiline string literals and symbols (note that this ignores lines with spaces at their
   # beginnings, assuming doc and inline regex don't match these lines anyway)
-  parsed_data = getParseData(parse(text = x, keep.source = TRUE))
-  is_matchable = seq_along(x) %in% unique(parsed_data[parsed_data$col1 == 1, 'line1'])
+  is_matchable = function(x) {
+    # if code can't be parsed, assume all lines are matchable
+    p = tryCatch(parse(text = x, keep.source = TRUE), error = function(e) NULL)
+    n = length(x)
+    if (is.null(p)) return(rep(TRUE, n))
+    d = getParseData(p)
+    seq_len(n) %in% d[d$col1 == 1, 'line1']
+  }
+  matchable = is_matchable(x)
 
   # .Rmd/.qmd need to be treated specially
   is_md = grepl('^[Rq]md$', format)
   p = if (is_md) .fmt.rmd(x) else .fmt.pat[[tolower(format)]]
 
   # turn {{expr}} into inline expressions, e.g. `r expr` or \Sexpr{expr}
-  if (any(i <- is_matchable & grepl(inline, x))) x[i] = gsub(inline, p[4], x[i])
+  if (any(i <- matchable & grepl(inline, x))) x[i] = gsub(inline, p[4], x[i])
 
-  r = rle((is_matchable & grepl(doc, x)) | i)  # inline expressions are treated as doc instead of code
+  r = rle((matchable & grepl(doc, x)) | i)  # inline expressions are treated as doc instead of code
   n = length(r$lengths); txt = vector('list', n); idx = c(0L, cumsum(r$lengths))
 
   for (i in seq_len(n)) {