Merge pull request #250 from krlmlr/218-mutate-twice

Test for inability to mutate a column twice
hadley · Apr 10, 2015 · 2d46bab · 2d46bab
2 parents dfaa738 + 9047781
commit 2d46bab
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/tests/testthat/test-mutate.r b/tests/testthat/test-mutate.r
@@ -16,3 +16,9 @@ test_that("columns can depend on previously created", {
 
   expect_that(m1$dm2, equals(dm2))
 })
+
+test_that("mutating a column twice does not work", {
+  # For compatibility, see #218
+  m1 <- mutate(airquality, dm = 0, dm = Month + Day / 31)
+  expect_equal(m1$dm, rep(0, length(m1$dm)))
+})