Replaced manual path construction with os.path.join

Signed-off-by: Ari <aribasch@umich.edu>

Author: aribasch

tests/test_api.py

@@ -134,7 +134,9 @@ def test_md_read_write_file_exceptions(self) -> None:
 
         # Test serializing to a file with bad filename
         with self.assertRaises(exceptions.StorageError):
-            md = Metadata.from_file(f"{self.repo_dir}/metadata/root.json")
+            md = Metadata.from_file(
+                os.path.join(self.repo_dir, "metadata", "root.json")
+            )
             md.to_file("")
 
     def test_compact_json(self) -> None:
@@ -159,7 +161,9 @@ def test_read_write_read_compare(self) -> None:
 
     def test_serialize_with_validate(self) -> None:
         # Assert that by changing one required attribute validation will fail.
-        root = Metadata.from_file(f"{self.repo_dir}/metadata/root.json")
+        root = Metadata.from_file(
+            os.path.join(self.repo_dir, "metadata", "root.json")
+        )
         root.signed.version = 0
         with self.assertRaises(SerializationError):
             root.to_bytes(JSONSerializer(validate=True))
@@ -233,7 +237,9 @@ def test_sign_verify(self) -> None:
     def test_sign_failures(self) -> None:
         # Test throwing UnsignedMetadataError because of signing problems
         # related to bad information in the signer.
-        md = Metadata.from_file(f"{self.repo_dir}/metadata/snapshot.json")
+        md = Metadata.from_file(
+            os.path.join(self.repo_dir, "metadata", "snapshot.json")
+        )
         key_dict = copy(self.keystore[Snapshot.type])
         key_dict["keytype"] = "rsa"
         key_dict["scheme"] = "bad_scheme"

tests/test_fetcher_ng.py

@@ -50,7 +50,7 @@ def setUpClass(cls) -> None:
             f"{str(cls.server_process_handler.port)}"
         )
         target_filename = os.path.basename(cls.target_file.name)
-        cls.url = f"{cls.url_prefix}/{target_filename}"
+        cls.url = os.path.join(cls.url_prefix, target_filename)
 
     @classmethod
     def tearDownClass(cls) -> None:
@@ -102,7 +102,7 @@ def test_url_parsing(self) -> None:
     # File not found error
     def test_http_error(self) -> None:
         with self.assertRaises(exceptions.DownloadHTTPError) as cm:
-            self.url = f"{self.url_prefix}/non-existing-path"
+            self.url = os.path.join(self.url_prefix, "non-existing-path")
             self.fetcher.fetch(self.url)
         self.assertEqual(cm.exception.status_code, 404)
 

tests/test_updater_ng.py

@@ -104,8 +104,8 @@ def setUp(self) -> None:
             + repository_basepath.replace("\\", "/")
         )
 
-        self.metadata_url = f"{url_prefix}/metadata/"
-        self.targets_url = f"{url_prefix}/targets/"
+        self.metadata_url = os.path.join(url_prefix, "metadata", "")
+        self.targets_url = os.path.join(url_prefix, "targets", "")
         self.dl_dir = tempfile.mkdtemp(dir=self.tmp_test_dir)
         # Creating a repository instance.  The test cases will use this client
         # updater to refresh metadata, fetch target files, etc.

tests/test_updater_top_level_update.py

@@ -774,7 +774,9 @@ def test_expired_metadata(self, mock_time: Mock) -> None:
         # which means a successful refresh is performed
         # with expired local metadata
         for role in ["timestamp", "snapshot", "targets"]:
-            md = Metadata.from_file(f"{self.metadata_dir}/{role}.json")
+            md = Metadata.from_file(
+                os.path.join(self.metadata_dir, f"{role}.json")
+            )
             self.assertEqual(md.signed.version, 2)