Use importlib.resources to load schema and licenses (#670)

src/poetry/core/json/__init__.py

@@ -1,8 +1,10 @@
 from __future__ import annotations
 
 import json
+import sys
 
 from pathlib import Path
+from typing import TYPE_CHECKING
 from typing import Any
 
 import fastjsonschema
@@ -13,14 +15,29 @@
 SCHEMA_DIR = Path(__file__).parent / "schemas"
 
 
+if sys.version_info < (3, 9):
+
+    def _get_schema_file(schema_name: str) -> Path:
+        return SCHEMA_DIR / f"{schema_name}.json"
+
+else:
+    from importlib.resources import files
+
+    if TYPE_CHECKING:
+        from importlib.abc import Traversable
+
+    def _get_schema_file(schema_name: str) -> Traversable:
+        return files(__package__) / "schemas" / f"{schema_name}.json"
+
+
 class ValidationError(ValueError):
     pass
 
 
 def validate_object(obj: dict[str, Any], schema_name: str) -> list[str]:
-    schema_file = SCHEMA_DIR / f"{schema_name}.json"
+    schema_file = _get_schema_file(schema_name)
 
-    if not schema_file.exists():
+    if not schema_file.is_file():
         raise ValueError(f"Schema {schema_name} does not exist.")
 
     with schema_file.open(encoding="utf-8") as f:

src/poetry/core/spdx/helpers.py

@@ -2,12 +2,29 @@
 
 import functools
 import json
+import sys
 
-from pathlib import Path
+from typing import TYPE_CHECKING
 
 from poetry.core.spdx.license import License
 
 
+if sys.version_info < (3, 9):
+    from pathlib import Path
+
+    def _get_license_file() -> Path:
+        return Path(__file__).parent / "data" / "licenses.json"
+
+else:
+    from importlib.resources import files
+
+    if TYPE_CHECKING:
+        from importlib.abc import Traversable
+
+    def _get_license_file() -> Traversable:
+        return files(__package__) / "data" / "licenses.json"
+
+
 def license_by_id(identifier: str) -> License:
     if not identifier:
         raise ValueError("A license identifier is required")
@@ -21,7 +38,7 @@ def license_by_id(identifier: str) -> License:
 @functools.lru_cache
 def _load_licenses() -> dict[str, License]:
     licenses = {}
-    licenses_file = Path(__file__).parent / "data" / "licenses.json"
+    licenses_file = _get_license_file()
 
     with licenses_file.open(encoding="utf-8") as f:
         data = json.load(f)