Rethrow yaml parsing error (add a clickable link to _pkgdown.yml) (#2559

)

Co-authored-by: Hadley Wickham <[email protected]>

R/package.R

@@ -182,15 +182,23 @@ pkgdown_config_path <- function(path) {
   )
 }
 
-read_meta <- function(path) {
+read_meta <- function(path, call = caller_env()) {
   path <- pkgdown_config_path(path)
 
   if (is.null(path)) {
     yaml <- list()
   } else {
-    yaml <- yaml::yaml.load_file(path) %||% list()
+    yaml <- withCallingHandlers(
+      yaml::yaml.load_file(path, error.label = NULL) %||% list(),
+      error = function(e) {
+        cli::cli_abort(
+          "Could not parse config file at {.path {path}}.",
+          call = call,
+          parent = e
+        )
+      }
+    )
   }
-
   yaml
 }
 

tests/testthat/_snaps/package.md

@@ -20,3 +20,13 @@
       ! template.bootstrap must be 3 or 5, not 1.
       i Edit _pkgdown.yml to fix the problem.
 
+# read_meta() errors gracefully if _pkgdown.yml failed to parse
+
+    Code
+      as_pkgdown(pkg$src_path)
+    Condition
+      Error in `as_pkgdown()`:
+      ! Could not parse config file at '<src>/_pkgdown.yml'.
+      Caused by error in `yaml.load()`:
+      ! Scanner error: mapping values are not allowed in this context at line 2, column 8
+

tests/testthat/test-package.R

@@ -82,3 +82,16 @@ test_that("titles don't get autolinked code", {
   rd <- rd_text("\\title{\\code{foo()}}", fragment = FALSE)
   expect_equal(extract_title(rd), "<code>foo()</code>")
 })
+
+test_that("read_meta() errors gracefully if _pkgdown.yml failed to parse", {
+  pkg <- local_pkgdown_site()
+  write_lines(path = path(pkg$src_path, "_pkgdown.yml"), c(
+    "url: https://pkgdown.r-lib.org",
+    "  title: Build websites for R packages"
+  ))
+  expect_snapshot(
+    as_pkgdown(pkg$src_path),
+    error = TRUE,
+    transform = function(x) gsub(pkg$src_path, "<src>", x, fixed = TRUE)
+  )
+})