Merge branch 'master' into text_answer

* master:
  Aggressive Prerender checks within rmarkdown (rstudio#179)

DESCRIPTION

@@ -1,10 +1,11 @@
 Package: learnr
 Type: Package
 Title: Interactive Tutorials for R
-Version: 0.9.2
+Version: 0.9.2.9000
 Authors@R: c(
-  person("Barbara", "Borges", role = c("aut", "cre"), email = "barbara@rstudio.com"),
+  person("Barret", "Schloerke", role = c("aut", "cre"), email = "barret@rstudio.com"),
   person("JJ", "Allaire", role = "aut", email = "jj@rstudio.com"),
+  person("Barbara", "Borges", role = "aut", email = "barbara@rstudio.com"),
   person(family = "RStudio, Inc.", role = "cph"),
   person(family = "Ajax.org B.V.", role=c("ctb", "cph"), comment= "Ace library"),
   person("Zeno", "Rocha", role = c("ctb", "cph"), comment = "clipboard.js library"),
@@ -32,7 +33,9 @@ Imports:
   knitr (>= 1.14),
   markdown,
   shiny (>= 1.0),
-  rmarkdown (>= 1.8)
+  rmarkdown (>= 1.10.14)
+Remotes:
+  rstudio/rmarkdown
 Encoding: UTF-8
 LazyData: true
 RoxygenNote: 6.1.0

NEWS.md

@@ -1,8 +1,10 @@
-learnr 0.9.3
+learnr 0.9.2.9000 (unreleased)
 ===========
 
 * Fixed a spurious console warning when running exercises using Pandoc 2.0. ([#154](https://github.com/rstudio/learnr/issues/154))
 
+* Aggressively rerender prerendered tutorials in favor of a cohesive exercise environment ([#169](https://github.com/rstudio/learnr/issues/169), [#179](https://github.com/rstudio/learnr/pull/179), and [rstudio/rmarkdown#1420](https://github.com/rstudio/rmarkdown/pull/1420))
+
 * Added a new function, `safe`, which evaluates code in a new, safe R environment. ([#174](https://github.com/rstudio/learnr/pull/174))
 
 learnr 0.9.2

R/run.R

@@ -35,11 +35,13 @@ run_tutorial <- function(name, package, shiny_args = NULL) {
     )
   }
 
-  # run within tutorial wd and ensure we don't call rmarkdown::render
+  # run within tutorial wd
   withr::with_dir(tutorial_path, {
-    withr::with_envvar(c(RMARKDOWN_RUN_PRERENDER = "0"), {
-      rmarkdown::run(file = NULL, dir = tutorial_path, shiny_args = shiny_args)
-    })
+    if (!identical(Sys.getenv("SHINY_PORT", ""), "")) {
+      # is currently running in a server, do not allow for prerender (rmarkdown::render)
+      withr::local_envvar(c(RMARKDOWN_RUN_PRERENDER = "0"))
+    }
+    rmarkdown::run(file = NULL, dir = tutorial_path, shiny_args = shiny_args)
   })
 }