BUG: return print to warn and expect warn in test

Author: Gnefil

mne/evoked.py

@@ -1564,7 +1564,7 @@ def _check_evokeds_ch_names_times(all_evoked, inplace=False):
             if set(ev.ch_names) != set(ch_names):
                 raise ValueError(f"{evoked} and {ev} do not contain the same channels.")
             else:
-                print("Order of channels differs, reordering channels ...")
+                warn("Order of channels differs, reordering channels ...")
                 if not inplace:
                     ev = ev.copy()
                 ev.reorder_channels(ch_names)

mne/viz/tests/test_evoked.py

@@ -478,9 +478,11 @@ def test_plot_compare_evokeds(evoked):
     evoked_subset = evoked.copy().pick(["MEG 0113", "MEG 0112"])
     evoked_reordered = evoked_subset.copy()
     evoked_reordered.reorder_channels(["MEG 0112", "MEG 0113"])
-    figs = plot_compare_evokeds(
-        dict(orig=evoked_subset, reordered=evoked_reordered), axes="topo"
-    )
+    # catch warnings when testing misalignment on purpose
+    with pytest.warns(RuntimeWarning, match="Order of channels differs"):
+        figs = plot_compare_evokeds(
+            dict(orig=evoked_subset, reordered=evoked_reordered), axes="topo"
+        )
     assert_allclose(
         figs[0].axes[0].lines[0].get_ydata(), figs[0].axes[0].lines[1].get_ydata()
     )