Add API to retrieve project metadata from an installed package.

pyroma/projectdata.py

@@ -4,6 +4,7 @@
 import os
 import pathlib
 import re
+from importlib.metadata import metadata
 
 from setuptools.config.setupcfg import read_configuration
 from distutils.errors import DistutilsFileError
@@ -39,20 +40,24 @@ def wheel_metadata(path, isolated=None):
 
 def build_metadata(path, isolated=None):
     try:
-        metadata = wheel_metadata(path, isolated)
+        data = wheel_metadata(path, isolated)
     except build.BuildBackendException:
         # The backend failed spectacularily. This happens with old packages,
         # when we can't build a wheel. It's not always a fatal error. F ex, if
         # you are getting info for a package from PyPI, we already have the
         # metadata from PyPI, we just couldn't get the additional build data.
         return {"_wheel_build_failed": True}
 
+    return normalize_metadata(data)
+
+
+def normalize_metadata(data):
     # As far as I can tell, we can't trust that the builders normalize the keys,
     # so we do it here. Definitely most builders do not lower case them, which
     # Core Metadata Specs recommend.
-    data = {}
-    for key in set(metadata.keys()):
-        value = metadata.get_all(key)
+    normalized = {}
+    for key in set(data.keys()):
+        value = data.get_all(key)
         key = normalize(key)
 
         if len(value) == 1:
@@ -61,15 +66,20 @@ def build_metadata(path, isolated=None):
                 # XXX This is also old behavior that may not hjappen any more.
                 continue
 
-        data[key] = value
+        normalized[key] = value
 
-    if "description" not in data.keys():
+    if "description" not in normalized.keys():
         # XXX I *think* having the description as a payload doesn't happen anymore, but I haven't checked.
         # Having the description as a payload tends to add two newlines, we clean that up here:
-        description = metadata.get_payload().strip()
+        description = data.get_payload().strip()
         if description:
-            data["description"] = description + "\n"
-    return data
+            normalized["description"] = description + "\n"
+    return normalized
+
+
+def installed_metadata(name):
+    """Retrieve the metadata for an package that is installed in the environment."""
+    return normalize_metadata(metadata(name))
 
 
 def get_build_data(path, isolated=None):

pyroma/tests.py

@@ -334,6 +334,43 @@ def test_complete(self):
         del data["_path"]  # This changes, so I just ignore it
         self.assertEqual(data, COMPLETE)
 
+    def test_installed(self):
+        # pyroma must be installed in the test environment.
+        data = projectdata.installed_metadata("pyroma")
+
+        # Verify some key metadata
+        self.assertEqual(data["name"], "pyroma")
+        self.assertEqual(data["summary"], "Test your project's packaging friendliness")
+        self.assertEqual(
+            data["classifier"],
+            [
+                "Development Status :: 5 - Production/Stable",
+                "Intended Audience :: Developers",
+                "License :: OSI Approved :: MIT License",
+                "Operating System :: OS Independent",
+                "Programming Language :: Python",
+                "Programming Language :: Python :: 3",
+                "Programming Language :: Python :: 3.9",
+                "Programming Language :: Python :: 3.10",
+                "Programming Language :: Python :: 3.11",
+                "Programming Language :: Python :: 3.12",
+                "Programming Language :: Python :: 3.13",
+                "Programming Language :: Python :: 3.14",
+                "Programming Language :: Python :: 3 :: Only",
+                "Programming Language :: Python :: Implementation :: CPython",
+                "Programming Language :: Python :: Implementation :: PyPy",
+            ],
+        )
+        self.assertEqual(data["keywords"], "pypi,quality,testing")
+        self.assertEqual(data["author"], "Lennart Regebro")
+        self.assertEqual(data["author-email"], "[email protected]")
+        self.assertEqual(data["home-page"], "https://github.com/regebro/pyroma")
+        self.assertEqual(data["license"], "MIT")
+        self.assertEqual(data["license-file"], "LICENSE.txt")
+        self.assertEqual(data["project-url"], "Source Code, https://github.com/regebro/pyroma")
+        self.assertEqual(data["provides-extra"], "test")
+        self.assertEqual(data["requires-python"], ">=3.9")
+
 
 class DistroDataTest(unittest.TestCase):
     maxDiff = None