[Backport main] Refactor constraints

AddonManagerTest/app/test_python_constraints.py

@@ -0,0 +1,125 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+# SPDX-FileCopyrightText: 2026 The FreeCAD project association AISBL
+# SPDX-FileNotice: Part of the AddonManager.
+
+################################################################################
+#                                                                              #
+#   This addon is free software: you can redistribute it and/or modify         #
+#   it under the terms of the GNU Lesser General Public License as             #
+#   published by the Free Software Foundation, either version 2.1              #
+#   of the License, or (at your option) any later version.                     #
+#                                                                              #
+#   This addon is distributed in the hope that it will be useful,              #
+#   but WITHOUT ANY WARRANTY; without even the implied warranty                #
+#   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.                    #
+#   See the GNU Lesser General Public License for more details.                #
+#                                                                              #
+#   You should have received a copy of the GNU Lesser General Public           #
+#   License along with this addon. If not, see https://www.gnu.org/licenses    #
+#                                                                              #
+################################################################################
+
+import os
+import tempfile
+import unittest
+from unittest.mock import patch
+
+from addonmanager_python_constraints import PythonConstraints
+
+SAMPLE_CONSTRAINTS = """# Header comment, may contain non-ascii like the real file
+# SPDX-License-Identifier: CC0-1.0
+
+kicad-python==0.7.1
+numpy==2.4.6
+Some_Package==1.2.3
+not-a-pin
+"""
+
+
+class TestPythonConstraints(unittest.TestCase):
+
+    def setUp(self):
+        self.temp_dir = tempfile.TemporaryDirectory()
+        self.cache_path = os.path.join(self.temp_dir.name, "constraints-cache.txt")
+
+    def tearDown(self):
+        self.temp_dir.cleanup()
+
+    def _patched(self, location, fetched_bytes):
+        """Build a PythonConstraints with the location, remote fetch, and cache file
+        redirected for testing."""
+        constraints = PythonConstraints()
+        patches = [
+            patch(
+                "addonmanager_python_constraints.resolve_constraints_location",
+                return_value=location,
+            ),
+            patch(
+                "addonmanager_python_constraints.blocking_get",
+                return_value=fetched_bytes,
+            ),
+            patch.object(PythonConstraints, "_cache_file", return_value=self.cache_path),
+        ]
+        for active_patch in patches:
+            active_patch.start()
+            self.addCleanup(active_patch.stop)
+        return constraints
+
+    def test_parse_ignores_comments_blanks_and_unpinned(self):
+        versions = PythonConstraints._parse(SAMPLE_CONSTRAINTS)
+        self.assertEqual(versions["kicad-python"], "0.7.1")
+        self.assertEqual(versions["numpy"], "2.4.6")
+        self.assertNotIn("not-a-pin", versions)
+        self.assertEqual(len(versions), 3)
+
+    def test_parse_normalizes_names(self):
+        versions = PythonConstraints._parse(SAMPLE_CONSTRAINTS)
+        self.assertIn("some-package", versions)
+        self.assertNotIn("Some_Package", versions)
+
+    def test_fetch_from_https_populates_and_caches(self):
+        constraints = self._patched(
+            "https://example.test/3.13/constraints.txt", SAMPLE_CONSTRAINTS.encode("utf-8")
+        )
+        self.assertEqual(constraints.version_for("kicad-python"), "0.7.1")
+        self.assertIn("numpy", constraints.allowed_packages())
+        self.assertTrue(os.path.exists(self.cache_path))
+
+    def test_falls_back_to_cache_when_fetch_is_empty(self):
+        with open(self.cache_path, "w", encoding="utf-8") as cache_file:
+            cache_file.write("cached-package==9.9.9\n")
+        constraints = self._patched("https://example.test/3.13/constraints.txt", b"")
+        self.assertEqual(constraints.version_for("cached-package"), "9.9.9")
+
+    def test_version_for_normalizes_query(self):
+        constraints = self._patched(
+            "https://example.test/3.13/constraints.txt", SAMPLE_CONSTRAINTS.encode("utf-8")
+        )
+        self.assertEqual(constraints.version_for("kicad_python"), "0.7.1")
+
+    def test_disabled_constraints_yield_empty_allow_list(self):
+        constraints = self._patched(None, b"")
+        self.assertEqual(constraints.allowed_packages(), set())
+        self.assertIsNone(constraints.version_for("numpy"))
+
+    def test_local_path_is_read_from_disk(self):
+        local_file = os.path.join(self.temp_dir.name, "constraints.txt")
+        with open(local_file, "w", encoding="utf-8") as handle:
+            handle.write("local-package==4.5.6\n")
+        constraints = self._patched(local_file, b"")
+        self.assertEqual(constraints.version_for("local-package"), "4.5.6")
+
+    def test_is_enabled_reflects_location(self):
+        with patch(
+            "addonmanager_python_constraints.resolve_constraints_location", return_value=None
+        ):
+            self.assertFalse(PythonConstraints.is_enabled())
+        with patch(
+            "addonmanager_python_constraints.resolve_constraints_location",
+            return_value="https://example.test/3.13/constraints.txt",
+        ):
+            self.assertTrue(PythonConstraints.is_enabled())
+
+
+if __name__ == "__main__":
+    unittest.main()