Test of new eval-handling

R/loop-transformation.R

@@ -3,7 +3,7 @@
 # we would otherwise get a complaint that `escape` is not defined. Everywhere
 # when we actually call a `escape` function, it is a continuation from calls to
 # `callCC`.
-escape <- function(x) x
+escape <- function(x) x # nocov
 
 ## Test for possibility of transformation #########################################
 
@@ -48,7 +48,7 @@ can_call_be_transformed <- function(call_name, call_arguments,
                     "are tail-recursive, so such expressions are not analysed and left alone in ",
                     "transformations."
                 ),
-                call = expr
+                call = rlang::expr(eval(!!! call_arguments))
             )
             warning(msg)
             return(TRUE) # get out, and hope the user knows what he is doing...

tests/testthat/test-loop-transformation.R

@@ -125,3 +125,22 @@ test_that("we can handle `with` expressions", {
         expect_equal(f(x), transformed_f(x))
     }
 })
+
+test_that("we warn about eval expressions, but leave them alone", {
+    # a valid tail-recurive function
+    f <- function(x) if (x < 0) x else eval(quote(f(-1)))
+    # an invalid tail-recursive function
+    g <- function(x) if (x < 0) x else eval(quote(g(-1) + g(-2)))
+
+    expect_warning(
+        can_loop_transform(f),
+        "This function contains an eval-expression.*"
+    )
+    expect_warning(
+        can_loop_transform(g),
+        "This function contains an eval-expression.*"
+    )
+
+    # I'm not sure how to easilly check that eval-expressions are
+    # left alone, though...
+})