explicitly warn against whitespace in app name and filename

README.md

@@ -93,7 +93,9 @@ Archive filenames and patch filenames follow the pattern
 
 `<name>-<version><suffix>` 
 
-where `name` is a short string that may contain alphanumeric characters, underscores, and hyphens, `version` is a version string according to the [PEP440][6] specification, and `suffix` is either `'.tar.gz'` or `'.patch'`.
+where `name` is a short string that may *only* contain *alphanumeric characters*, *underscores*, and *hyphens*, `version` is a version string according to the [PEP440][6] specification, and `suffix` is either `'.tar.gz'` or `'.patch'`.
+
+***BEWARE***: *whitespace* is NOT allowed in the filename.
 
 Patches are typically smaller than archives, so the tufup *client* will always attempt to update using one or more patches.
 However, if the total amount of patch data is greater than the desired full archive file, a full update will be performed.

examples/client/example_app.py

@@ -13,7 +13,7 @@
 #   python -m http.server -d examples/repo/content
 
 # App info
-APP_NAME = 'example_app'
+APP_NAME = 'example_app'  # BEWARE: app name cannot contain whitespace
 CURRENT_VERSION = '1.0'
 
 # For this example, all files are stored in the tufup/examples/client

src/tufup/common.py

@@ -26,8 +26,10 @@ def __init__(
             is_archive: Optional[bool] = True,
     ):
         """
-
         Initialize either with target_path, or with name, version, archive.
+
+        BEWARE: whitespace is not allowed in the filename,
+        nor in the `name` or `version` arguments
         """
         super().__init__()
         if target_path is None:
@@ -36,6 +38,10 @@ def __init__(
             )
         self.target_path_str = str(target_path)  # keep the original for reference
         self.path = pathlib.Path(target_path)
+        if ' ' in self.filename:
+            logger.critical(
+                f'invalid filename "{self.filename}": whitespace not allowed'
+            )
 
     def __str__(self):
         return str(self.target_path_str)
@@ -85,7 +91,7 @@ def version(self) -> Optional[Version]:
             version = Version(match_dict.get('version', ''))
         except InvalidVersion:
             version = None
-            logger.debug(f'No valid version in filename: {self.filename}')
+            logger.critical(f'No valid version in filename: {self.filename}')
         return version
 
     @property

tests/test_common.py

@@ -1,3 +1,4 @@
+import logging
 import pathlib
 
 import bsdiff4
@@ -8,6 +9,15 @@
 
 
 class TestTargetMeta(TempDirTestCase):
+    def test_init_whitespace(self):
+        for kwargs in [
+            dict(target_path='w h i t e s p a c e-1.2.3.tar.gz'),
+            dict(name='w h i t e s p a c e'),
+        ]:
+            with self.subTest(msg=kwargs):
+                with self.assertLogs(level=logging.CRITICAL):
+                    TargetMeta(**kwargs)
+
     def test_eq_ne(self):
         target_meta = TargetMeta()
         self.assertEqual(target_meta, TargetMeta())