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

DESCRIPTION

@@ -34,7 +34,7 @@ Imports:
     purrr (>= 1.0.0),
     ragg,
     rlang (>= 1.1.0),
-    rmarkdown (>= 2.26.2),
+    rmarkdown (>= 2.27),
     tibble,
     whisker,
     withr (>= 2.4.3),
@@ -72,5 +72,3 @@ Encoding: UTF-8
 Roxygen: list(markdown = TRUE)
 RoxygenNote: 7.3.1
 SystemRequirements: pandoc
-Remotes:  
-    rstudio/rmarkdown

R/package.R

@@ -178,15 +178,38 @@ pkgdown_config_path <- function(path) {
   )
 }
 
-read_meta <- function(path) {
-  path <- pkgdown_config_path(path)
+read_meta <- function(path, check_path = TRUE, call = caller_env()) {
+  if (check_path) {
+    # check_path = FALSE can be used to supply a direct path to
+    # read_meta instead of a pkgdown object.
+    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) %||% list(),
+      error = function(e) {
+        # Tweak the original message to put the location of the error at the end
+        # based on yaml 2.3.8 error message structure
+        # (<<path>>) Parser error: <<parsing error>>
+        yaml_err <- conditionMessage(e)
+        # extract parsing error from original error (i.e. remove the path)
+        parsing_error <- sub("[^\\)]+\\)", "", yaml_err)
+        # Extract path from original error
+        path_yaml <- regmatches(yaml_err, m = regexpr("\\(([^\\)]+)\\)", yaml_err))
+        path_yaml <- gsub("\\(([^\\)]+)\\)", "\\1", path_yaml)
+        # Rethrow cli-styled error!
+        cli::cli_abort(c(
+          "x" = "Could not parse the config file.",
+          "!" = parsing_error,
+          "i" = "Edit {.path {path_yaml}} to fix the problem."
+          ),
+          call = call
+        )
+      })
   }
-
   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
+      read_meta(file, check_path = FALSE)
+    Condition
+      Error:
+      x Could not parse the config file.
+      !  Parser error: while parsing a block mapping at line 1, column 1 did not find expected key at line 9, column 3
+      i Edit 'assets/bad-yaml/_pkgdown.yml' to fix the problem.
+

tests/testthat/assets/bad-yaml/_pkgdown.yml

@@ -0,0 +1,16 @@
+url: https://pkgdown.r-lib.org
+
+home:
+  title: Build websites for R packages
+
+authors:
+   Jay Hesselberth:
+    href: https://hesselberthlab.org
+  Maëlle Salmon:
+    href: https://masalmon.eu
+  Hadley Wickham:
+    href: http://hadley.nz
+  Posit Software, PBC:
+    href: https://www.posit.co
+    html: >-
+      <img src='https://www.tidyverse.org/posit-logo.svg' alt='Posit' width='62' height='16' style="margin-bottom: 3px;" />

tests/testthat/test-package.R

@@ -56,10 +56,10 @@ test_that("package_vignettes() sorts articles alphabetically by file name", {
 
 test_that("override works correctly for as_pkgdown", {
   pkgdown <- as_pkgdown(test_path("assets/articles-images"))
-  
+
   expected_list <- list(dev = "jpeg", fig.ext = "jpg", fig.width = 3, fig.asp = 1)
   expect_equal(pkgdown$meta$figures, expected_list)
-  
+
   modified_pkgdown <- as_pkgdown(pkgdown, override = list(figures = list(dev = "png")))
   expect_equal(modified_pkgdown$meta$figures$dev, "png")
 })
@@ -82,3 +82,14 @@ 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", {
+  file <- test_path("assets", "bad-yaml", "_pkgdown.yml")
+  expect_snapshot(
+    error = TRUE,
+    read_meta(
+      file,
+      check_path = FALSE
+    )
+  )
+})