diff --git a/R/import.R b/R/import.R
index 587a3f38..0dfbab53 100644
--- a/R/import.R
+++ b/R/import.R
@@ -18,6 +18,8 @@ get_cr_md <- function(dois,
   out
 }
 
+# wrapped cr api calls ====
+
 #' Get Crossref Works
 #'
 #' Type-/length-stable, defensive and cached variant of [rcrossref::cr_works()].
diff --git a/tests/testthat/test-import.R b/tests/testthat/test-import.R
index 051cb61b..39be3e14 100644
--- a/tests/testthat/test-import.R
+++ b/tests/testthat/test-import.R
@@ -1,8 +1,24 @@
-test_that("Crossref metadata can be read in", {
-  dois <- tu_dois()[2:5]
-  res <- cr_works2(dois)
-  expect_equal(nrow(res), length(dois))
+# wrapped cr api calls ====
+
+dois <- tu_dois()[2:5]
+
+test_that("Crossref metadata can be read in", {  
   # testthat does not seem to know about vctrs equality
   # https://github.com/r-lib/testthat/issues/1349
-  expect_true(all(biblids::as_doi(res$doi) == biblids::as_doi(dois)))
+  expect_true(
+    all(biblids::as_doi(cr_works2(dois)$doi) == biblids::as_doi(dois))
+  )
+})
+
+test_that("cr_works2 is length-stable", {
+  expect_equal(nrow(cr_works2(dois)), length(dois))
+  expect_equal(nrow(cr_works2(dois[1])), 1)
+  skip("Length instability in columns cannot be repaired by wrapper.")
+  # blocked by https://github.com/subugoe/metacheck/issues/183
+  expect_equal(ncol(cr_works2(dois)), ncol(cr_works2(dois[1])))
+})
+
+test_that("Bad DOIs throw error", {
+  skip("Not implemented")
+  expect_equal(1, 1)
 })