Get @example working with R6 (#1821)

Fixes #1158

Author: hadley

NEWS.md

@@ -5,6 +5,7 @@
 * R6 improvements:
   * The "Super classes" section now omits the `pkg::` prefix for parent classes from the same package, making the inheritance chain easier to read (#1567).
   * R6 classes with only active bindings and `cloneable = FALSE` no longer error during documentation (#1610).
+  * `@example` (singular, with a file path) now works correctly in R6 class documentation (#1158).
   * Inherited method links now only link to parent classes that have documentation, avoiding broken links when parent classes are undocumented (#963, #1155).
   * `initialize()` method parameters now automatically inherit documentation from `@field` tags with the same name, reducing the need to duplicate descriptions. Explicit `@param` tags still take precedence (#1004).
 * New `needs_roxygenize()` provides a lightweight check that man pages are up-to-date by comparing modification times of `.Rd` files with their source files (#1411).

R/rd-r6.R

@@ -1,4 +1,4 @@
-topic_add_r6_methods <- function(rd, block, env) {
+topic_add_r6_methods <- function(rd, block, env, base_path) {
   docs <- r6_class_from_block(block, env)
 
   # Add class-level tags

R/rd.R

@@ -219,7 +219,7 @@ block_to_rd.roxy_block_r6class <- function(block, base_path, env) {
     return()
   }
 
-  topic_add_r6_methods(rd, block, env)
+  topic_add_r6_methods(rd, block, env, base_path)
 
   describe_rdname <- topic_add_describe_in(rd, block, env)
   filename <- describe_rdname %||%

tests/testthat/_snaps/rd-r6.md

@@ -22,6 +22,7 @@
       Method 2 details.
       }
       \examples{
+      a <- A$new()
       ## Example for meth1
       ## Example for meth2
       

tests/testthat/testR6/R/classes.R

@@ -7,6 +7,7 @@
 #' Class A details
 #'
 #' @param Z zzzzzzz
+#' @example example.R
 
 A <- R6::R6Class(
   "A",

tests/testthat/testR6/example.R

@@ -0,0 +1 @@
+a <- A$new()