Ensure processor has extracted all members when members=None

pooch/processors.py

@@ -44,6 +44,13 @@ def __init__(self, members=None, extract_dir=None):
         self.members = members
         self.extract_dir = extract_dir
 
+    def _all_members(self, fname):
+        """Return all the members in the archive.
+
+        In the base class, this returns None.
+        """
+        return None
+
     def __call__(self, fname, action, pooch):
         """
         Extract all files from the given archive.
@@ -79,17 +86,13 @@ def __call__(self, fname, action, pooch):
         else:
             archive_dir = fname.rsplit(os.path.sep, maxsplit=1)[0]
             self.extract_dir = os.path.join(archive_dir, self.extract_dir)
+        members = self.members or self._all_members(fname)
         if (
             (action in ("update", "download"))
             or (not os.path.exists(self.extract_dir))
-            or (
-                (self.members is not None)
-                and (
-                    not all(
-                        os.path.exists(os.path.join(self.extract_dir, m))
-                        for m in self.members
-                    )
-                )
+            or not all(
+                os.path.exists(os.path.join(self.extract_dir, m))
+                for m in members
             )
         ):
             # Make sure that the folder with the extracted files exists
@@ -148,6 +151,11 @@ class Unzip(ExtractorProcessor):  # pylint: disable=too-few-public-methods
 
     suffix = ".unzip"
 
+    def _all_members(self, fname):
+        """Return all members from a given archive."""
+        with ZipFile(fname, "r") as zip_file:
+            return zip_file.namelist()
+
     def _extract_file(self, fname, extract_dir):
         """
         This method receives an argument for the archive to extract and the
@@ -209,6 +217,11 @@ class Untar(ExtractorProcessor):  # pylint: disable=too-few-public-methods
 
     suffix = ".untar"
 
+    def _all_members(self, fname):
+        """Return all members from a given archive."""
+        with TarFile.open(fname, "r") as tar_file:
+            return [info.name for info in tar_file.getmembers()]
+
     def _extract_file(self, fname, extract_dir):
         """
         This method receives an argument for the archive to extract and the

pooch/tests/test_processors.py

@@ -255,3 +255,28 @@ def _unpacking_expected_paths_and_logs(archive, members, path, name):
             log_lines.append(f"Extracting '{member}'")
         true_paths = set(true_paths)
     return true_paths, log_lines
+
+
+@pytest.mark.network
+@pytest.mark.parametrize(
+    "processor_class,extension",
+    [(Unzip, ".zip"), (Untar, ".tar.gz")],
+)
+def test_unpacking_members_then_no_members(processor_class, extension):
+    """Test that calling with members then without them works.
+
+    https://github.com/fatiando/pooch/issues/364
+    """
+
+    with TemporaryDirectory() as local_store:
+        pup = Pooch(path=Path(local_store), base_url=BASEURL, registry=REGISTRY)
+
+        # Do a first fetch with incorrect member
+        processor1 = processor_class(members=["i don't exist"])
+        filenames1 = pup.fetch("store" + extension, processor=processor1)
+        assert len(filenames1) == 0
+
+        # Do a second fetch with no members
+        processor2 = processor_class()
+        filenames2 = pup.fetch("store" + extension, processor=processor2)
+        assert len(filenames2) > 0