TST: Test contents of import, not that the command fails

tests/str_fixtures.py

@@ -17,6 +17,22 @@ institution = {Stanford InfoLab},
 }
 """
 
+bibtex_external_alt = """
+@techreport{Page99,
+     number = {1999-66},
+      month = {November},
+     author = {Lawrence Page and Sergey Brin and Rajeev Motwani and Terry Winograd},
+       note = {Previous number = SIDL-WP-1999-0120},
+      title = {The PageRank Citation Ranking: Bringing Order to the Web.},
+       type = {Technical Report},
+  publisher = {Stanford InfoLab},
+       year = {9999},
+institution = {Stanford InfoLab},
+        url = {http://ilpubs.stanford.edu:8090/422/},
+   abstract = "This is not a real entry, it is just here to test overwriting fails on import. it must have a different year than the str_fixture bibtex_external0, but must have the same citekey for the test to be valid.",
+}
+"""
+
 bibtex_raw0 = """@techreport{
     Page99,
     author = "Page, Lawrence and Brin, Sergey and Motwani, Rajeev and Winograd, Terry",

tests/test_usecase.py

@@ -884,14 +884,18 @@ class TestUsecase(DataCommandTestCase):
         self.assertEqual(1 + 1, len(outs[-1].split('\n')))
 
     def test_import_does_not_overwrite(self):
+        with FakeFileOpen(self.fs)('data/real.bib', 'w') as f:
+            f.write(str_fixtures.bibtex_external0)
+        with FakeFileOpen(self.fs)('data/fake.bib', 'w') as f:
+            f.write(str_fixtures.bibtex_external_alt)
         cmds = ['pubs init',
-                'pubs import data/ Page99',
-                'pubs import data/',
+                'pubs import data/real.bib Page99',
+                'pubs import data/fake.bib Page99',
                 'pubs list'
                ]
+        outs = self.execute_cmds(cmds)
+        self.assertEqual("(1999)", outs[-1][-8:].strip())
 
-        with self.assertRaises(FakeSystemExit):
-            self.execute_cmds(cmds)
 
     def test_import_overwrites(self):
         cmds = ['pubs init',