Improve the error message of fortify.default() (#4963)

Author: yutannihilation

R/fortify.r

@@ -35,7 +35,7 @@ fortify.grouped_df <- function(model, data, ...) {
 }
 #' @export
 fortify.default <- function(model, data, ...) {
-  msg <- "{.arg data} must be a {.cls data.frame}, or an object coercible by `fortify()`, not {obj_desc(model)}."
+  msg <- glue("{{.arg data}} must be a {{.cls data.frame}}, or an object coercible by `fortify()`, not {obj_desc(model)}.")
   if (inherits(model, "uneval")) {
     msg <- c(
       msg,

tests/testthat/_snaps/fortify.md

@@ -1,5 +1,5 @@
 # fortify.default proves a helpful error with class uneval
 
-    `data` must be a <data.frame>, or an object coercible by `fortify()`, not an S3 object with class {.cls uneval}.
+    `data` must be a <data.frame>, or an object coercible by `fortify()`, not an S3 object with class <uneval>.
     i Did you accidentally pass `aes()` to the `data` argument?