test_example() tweaks

Fixes #841

NEWS.md

@@ -1,5 +1,9 @@
 # testthat (development version)
 
+* `test_examples()` gets some minor fixes: it now returns the results 
+  invisibly, doesn't assume that examples should contain tests, and 
+  documents that you shouldn't be using it routinely (#841).
+
 * `fail()` and `suceed()` gain `info` argument, which is passed along to 
   `expect()`.
 

R/test-example.R

@@ -2,8 +2,10 @@
 #'
 #' These helper functions make it easier to test the examples in a package.
 #' Each example counts as one test, and it succeeds if the code runs without
-#' an error.
+#' an error. Generally, this is redundant with R CMD check, and is not
+#' recommended in routine practice.
 #'
+#' @keywords internal
 #' @param path For `test_examples()`, path to directory containing Rd files.
 #'   For `test_example()`, path to a single Rd file. Remember the working
 #'   directory for tests is `tests/testthat`.
@@ -14,7 +16,7 @@ test_examples <- function(path = "../..") {
   if (is.null(res)) {
     stop("Could not find examples", call. = FALSE)
   }
-  res
+  invisible(res)
 }
 
 test_examples_source <- function(path = "../..") {
@@ -40,33 +42,28 @@ test_examples_installed <- function(package = env_test$package) {
   lapply(Rd, test_rd)
 }
 
+
 #' @export
 #' @rdname test_examples
-test_example <- function(path) {
-  ex_path <- file.path(tempdir(), paste0(tools::file_path_sans_ext(basename(path)), ".R"))
-  tools::Rd2ex(path, ex_path)
-  if (!file.exists(ex_path)) return()
-
-  env <- new.env(parent = globalenv())
-
-  ok <- test_code(path, parse(ex_path, encoding = "UTF-8"), env = env)
-  if (ok) succeed(path)
-
-  invisible()
+test_rd <- function(rd) {
+  test_example(attr(rd, "Rdfile"))
 }
 
 #' @export
 #' @rdname test_examples
-test_rd <- function(rd) {
-  path <- attr(rd, "Rdfile")
+test_example <- function(path) {
   ex_path <- file.path(tempdir(), paste0(tools::file_path_sans_ext(basename(path)), ".R"))
-  tools::Rd2ex(rd, ex_path)
-  if (!file.exists(ex_path)) return()
+  tools::Rd2ex(path, ex_path)
+  if (!file.exists(ex_path)) return(invisible())
 
   env <- new.env(parent = globalenv())
 
-  ok <- test_code(path, parse(ex_path, encoding = "UTF-8"), env = env)
+  ok <- test_code(path,
+    parse(ex_path, encoding = "UTF-8"),
+    env = env,
+    skip_on_empty = FALSE
+  )
   if (ok) succeed(path)
 
-  invisible()
+  invisible(ok)
 }