change test to use csv instead of json

Author: ntdef

csv_diff/__init__.py

@@ -15,7 +15,7 @@ def load_csv(fp, key=None, dialect=None):
             # Oh well, we tried. Fallback to the default.
             pass
     fp = csv.reader(fp, dialect=(dialect or "excel"))
-    headings = next(fp)
+    headings = next(fp, [])
     rows = [dict(zip(headings, line)) for line in fp]
     if key:
         keyfn = lambda r: r[key]

tests/test_csv_diff.py

@@ -119,7 +119,7 @@ def test_tsv():
 
 def test_empty():
     diff = compare(
-        load_json(io.StringIO("[]"), key="id"), load_csv(io.StringIO(TWO_TSV), key="id")
+        load_csv(io.StringIO(""), key="id"), load_csv(io.StringIO(TWO_TSV), key="id")
     )
     assert {
         "added": [{"age": "5", "id": "1", "name": "Cleo"}, {"age": "2", "id": "2", "name": "Pancakes"}],