Fix status error on empty string

Author: fcollonval

jupyterlab_git/git.py

@@ -101,12 +101,17 @@ def call_subprocess(
 
     return code, output, error
 
-def strip_and_split(s):
-    """strip trailing \x00 and split on \x00
+def strip_and_split(s: "str") -> "List[str]":
+    """Strip trailing \x00 and split on \x00 a string.
 
     Useful for parsing output of git commands with -z flag.
     """
-    return s.strip("\x00").split("\x00")
+    s = s.strip("\x00")
+    if len(s) > 0:
+        return s.split("\x00")
+    else:
+        return list()
+
 
 class Git:
     """
@@ -263,7 +268,7 @@ async def status(self, current_path):
                 "to": line[3:],
                 # if file was renamed, next line contains original path
                 "from": next(line_iterable) if line[0]=='R' else line[3:]
-            })       
+            })
         return {"code": code, "files": result}
 
     async def log(self, current_path, history_count=10):

jupyterlab_git/tests/test_status.py

@@ -10,37 +10,67 @@
 
 from .testutils import FakeContentManager
 
+
 @pytest.mark.asyncio
-async def test_status():
+@pytest.mark.parametrize(
+    "output,expected",
+    [
+        (
+            (
+                "A  notebook with spaces.ipynb",
+                "M  notebook with λ.ipynb",
+                "R  renamed_to_θ.py",
+                "originally_named_π.py",
+                "?? untracked.ipynb",
+            ),
+            [
+                {
+                    "x": "A",
+                    "y": " ",
+                    "to": "notebook with spaces.ipynb",
+                    "from": "notebook with spaces.ipynb",
+                },
+                {
+                    "x": "M",
+                    "y": " ",
+                    "to": "notebook with λ.ipynb",
+                    "from": "notebook with λ.ipynb",
+                },
+                {
+                    "x": "R",
+                    "y": " ",
+                    "to": "renamed_to_θ.py",
+                    "from": "originally_named_π.py",
+                },
+                {
+                    "x": "?",
+                    "y": "?",
+                    "to": "untracked.ipynb",
+                    "from": "untracked.ipynb",
+                },
+            ],
+        ),
+        ((""), ([])),  # Empty answer
+    ],
+)
+async def test_status(output, expected):
     with patch("jupyterlab_git.git.execute") as mock_execute:
         # Given
-        process_output = (
-        "A  notebook with spaces.ipynb",
-        "M  notebook with λ.ipynb",
-        "R  renamed_to_θ.py",
-        "originally_named_π.py",
-        "?? untracked.ipynb",
-        )
-
-        expected_resonse = [
-            {"x": "A", "y": " ", "to": "notebook with spaces.ipynb", "from": "notebook with spaces.ipynb"},
-            {"x": "M", "y": " ", "to": "notebook with λ.ipynb", "from": "notebook with λ.ipynb"},
-            {"x": "R", "y": " ", "to": "renamed_to_θ.py", "from": "originally_named_π.py"},
-            {"x": "?", "y": "?", "to": "untracked.ipynb", "from": "untracked.ipynb"},
-        ]
+        root = "/bin"
+        repository = "test_curr_path"
         mock_execute.return_value = tornado.gen.maybe_future(
-            (0, "\x00".join(process_output), "")
-
+            (0, "\x00".join(output), "")
         )
 
         # When
-        actual_response = await Git(FakeContentManager("/bin")).status(
-            current_path="test_curr_path"
+        actual_response = await Git(FakeContentManager(root)).status(
+            current_path=repository
         )
 
         # Then
         mock_execute.assert_called_once_with(
-            ["git", "status", "--porcelain" , "-u", "-z"], cwd="/bin/test_curr_path"
+            ["git", "status", "--porcelain", "-u", "-z"],
+            cwd=os.path.join(root, repository),
         )
 
-        assert {"code": 0, "files": expected_resonse} == actual_response
+        assert {"code": 0, "files": expected} == actual_response