Merge pull request #31 from DavidCEllis/fix_import_cycle

Fix import cycle - test for import cycle in lazy imports

Author: DavidCEllis

src/ducktools/env/_lazy_imports.py

@@ -83,24 +83,5 @@
             "tomli",
             "tomllib",
         ),
-
-        # Internal Imports
-        FromImport(
-            ".bundle",
-            "create_bundle"
-        ),
-        FromImport(
-            ".scripts.get_pip",
-            "retrieve_pip"
-        ),
-        MultiFromImport(
-            ".scripts.get_uv",
-            ["retrieve_uv", "get_available_pythons", "install_uv_python"]
-        ),
-        MultiFromImport(
-            ".scripts.create_zipapp",
-            ["build_env_folder", "build_zipapp"]
-        ),
     ],
-    globs=globals(),
 )

src/ducktools/env/manager.py

@@ -25,6 +25,7 @@
 import os.path
 
 from ducktools.classbuilder.prefab import Prefab, attribute
+from ducktools.lazyimporter import LazyImporter, FromImport, MultiFromImport
 
 from . import (
     FOLDER_ENVVAR,
@@ -52,6 +53,23 @@
 from ._logger import log
 
 
+_laz_internal = LazyImporter(
+    [
+        FromImport(".bundle", "create_bundle"),
+        FromImport(".scripts.get_pip", "retrieve_pip"),
+        MultiFromImport(
+            ".scripts.get_uv",
+            ["retrieve_uv", "get_available_pythons", "install_uv_python"]
+        ),
+        MultiFromImport(
+            ".scripts.create_zipapp",
+            ["build_env_folder", "build_zipapp"]
+        ),
+    ],
+    globs=globals(),
+)
+
+
 class Manager(Prefab):
     project_name: str = PROJECT_NAME
     config: Config = None
@@ -110,11 +128,11 @@ def install_outdated(self):
 
     # Ducktools build commands
     def retrieve_pip(self) -> str:
-        return _laz.retrieve_pip(paths=self.paths)
+        return _laz_internal.retrieve_pip(paths=self.paths)
 
     def retrieve_uv(self, required=False) -> str | None:
         if self.config.use_uv or required:
-            uv_path = _laz.retrieve_uv(paths=self.paths)
+            uv_path = _laz_internal.retrieve_uv(paths=self.paths)
         else:
             uv_path = None
 
@@ -142,12 +160,12 @@ def _get_python_install(self, spec: EnvironmentSpec):
         else:
             # If no Python was matched try to install a matching python from UV
             if (uv_path := self.retrieve_uv()) and self.config.uv_install_python:
-                uv_pythons = _laz.get_available_pythons(uv_path)
+                uv_pythons = _laz_internal.get_available_pythons(uv_path)
                 matched_python = False
                 for ver in uv_pythons:
                     if spec.details.requires_python_spec.contains(ver):
                         # Install matching python
-                        _laz.install_uv_python(
+                        _laz_internal.install_uv_python(
                             uv_path=uv_path,
                             version_str=ver,
                         )
@@ -182,7 +200,7 @@ def build_env_folder(self, clear_old_builds=True) -> None:
         # build-env-folder installs into a target directory
         # instead of using a venv
         base_command = [sys.executable, self.retrieve_pip(), "--disable-pip-version-check"]
-        _laz.build_env_folder(
+        _laz_internal.build_env_folder(
             paths=self.paths,
             install_base_command=base_command,
             clear_old_builds=clear_old_builds,
@@ -191,7 +209,7 @@ def build_env_folder(self, clear_old_builds=True) -> None:
     def build_zipapp(self, clear_old_builds=True) -> None:
         """Build the ducktools.pyz zipapp"""
         base_command = [sys.executable, self.retrieve_pip(), "--disable-pip-version-check"]
-        _laz.build_zipapp(
+        _laz_internal.build_zipapp(
             paths=self.paths,
             install_base_command=base_command,
             clear_old_builds=clear_old_builds,
@@ -423,7 +441,7 @@ def create_bundle(
             generate_lock=generate_lock,
         )
 
-        _laz.create_bundle(
+        _laz_internal.create_bundle(
             spec=spec,
             output_file=output_file,
             paths=self.paths,

tests/test_no_import_cycle.py

@@ -0,0 +1,44 @@
+# ducktools.env
+# MIT License
+#
+# Copyright (c) 2024 David C Ellis
+#
+# 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.
+import os
+import sys
+
+import subprocess
+
+import ducktools.env
+
+
+def test_no_import_cycle():
+    env_vars = os.environ.copy()
+    env_vars["DUCKTOOLS_EAGER_IMPORT"] = "True"
+
+    # Just run the version command
+    output = subprocess.run(
+        [sys.executable, "-m", "ducktools.env", "--version"],
+        capture_output=True,
+        text=True,
+        env=env_vars,
+        check=True,
+    )
+
+    assert output.stdout.strip() == ducktools.env.__version__.strip()