Add tests for purl types

Signed-off-by: Tushar Goel <tushar.goel.dav@gmail.com>

Author: TG1999

src/packageurl/__init__.py

@@ -178,7 +178,7 @@ def normalize_qualifiers(
     Raise ValueError on errors.
     """
     if not qualifiers:
-        return None if encode else {}
+        return None
 
     if isinstance(qualifiers, basestring):
         qualifiers_str = qualifiers if isinstance(qualifiers, str) else qualifiers.decode("utf-8")

tests/test_purl_spec.py

@@ -1,3 +1,27 @@
+# Copyright (c) the purl authors
+# SPDX-License-Identifier: MIT
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+# Visit https://github.com/package-url/packageurl-python for support and
+# download.
+
 import json
 import os
 
@@ -57,3 +81,70 @@ def test_build(description, input_dict, expected_output, expected_failure):
     else:
         purl = PackageURL(**kwargs)
         assert purl.to_string() == expected_output
+
+
+def load_spec_files(spec_dir):
+    """
+    Load all JSON files from the given directory into a dictionary.
+    Key = filename, Value = parsed JSON content
+    """
+    spec_data = {}
+    for filename in os.listdir(spec_dir):
+        if filename.endswith("-test.json"):
+            filepath = os.path.join(spec_dir, filename)
+            with open(filepath, 'r', encoding='utf-8') as f:
+                try:
+                    data = json.load(f)
+                    spec_data[filename] = data["tests"]
+                except json.JSONDecodeError as e:
+                    print(f"Error parsing {filename}: {e}")
+    return spec_data
+
+
+SPEC_DIR = os.path.join(os.path.dirname(__file__), '..', 'spec', 'tests', 'types')
+spec_dict = load_spec_files(SPEC_DIR)
+
+flattened_cases = []
+for filename, cases in spec_dict.items():
+    for case in cases:
+        flattened_cases.append((filename, case["description"], case))
+
+
+@pytest.mark.parametrize("filename,description,test_case", flattened_cases)
+def test_package_type_case(filename, description, test_case):
+    test_type = test_case["test_type"]
+    expected_failure = test_case.get("expected_failure", False)
+
+    if expected_failure:
+        with pytest.raises(Exception):
+            run_test_case(test_case, test_type, description)
+    else:
+        run_test_case(test_case, test_type, description)
+
+
+def run_test_case(case, test_type, desc):
+    if test_type == "parse":
+        purl = PackageURL.from_string(case["input"])
+        expected = case["expected_output"]
+        assert purl.type == expected["type"]
+        assert purl.namespace == expected["namespace"]
+        assert purl.name == expected["name"]
+        assert purl.version == expected["version"]
+        assert purl.qualifiers == expected["qualifiers"]
+        assert purl.subpath == expected["subpath"]
+
+    elif test_type == "roundtrip":
+        purl = PackageURL.from_string(case["input"])
+        assert purl.to_string() == case["expected_output"]
+
+    elif test_type == "build":
+        input_data = case["input"]
+        purl = PackageURL(
+            type=input_data["type"],
+            namespace=input_data["namespace"],
+            name=input_data["name"],
+            version=input_data["version"],
+            qualifiers=input_data.get("qualifiers"),
+            subpath=input_data.get("subpath"),
+        )
+        assert purl.to_string() == case["expected_output"]