thanks @kartikeyakirar

NEWS.md

@@ -1,5 +1,6 @@
 # teal.code 0.3.0.9008
 
+* `eval_code` doesn't render plots in a graphical device.  
 * `chunks` have been removed. The new `qenv` object should be used instead. See the new `qenv` vignette in the package for further details.
 
 # teal.code 0.3.0

R/qenv-eval_code.R

@@ -20,6 +20,11 @@ setGeneric("eval_code", function(object, code) standardGeneric("eval_code"))
 #' @rdname eval_code
 #' @export
 setMethod("eval_code", signature = c("qenv", "expression"), function(object, code) {
+  if (interactive()) {
+    grDevices::pdf(file = NULL)
+    on.exit(dev.off())
+  }
+
   id <- sample.int(.Machine$integer.max, size = length(code))
 
   object@id <- c(object@id, id)

tests/testthat/test-qenv_eval_code.R

@@ -110,8 +110,6 @@ testthat::test_that("an error when calling eval_code returns a qenv.error object
 })
 
 testthat::test_that("a warning when calling eval_code returns a qenv object which has warnings", {
-  pdf(nullfile())
-  on.exit(dev.off())
   q <- eval_code(new_qenv(), quote("iris_data <- iris"))
   q <- eval_code(q, quote("p <- hist(iris_data[, 'Sepal.Length'], ff = '')"))
   testthat::expect_s4_class(q, "qenv")