Add CONDA_DEVENV_USE_LOCKS env var to configure the default for --use-locks

CHANGELOG.rst

@@ -2,6 +2,12 @@
 CHANGELOG
 =========
 
+3.2.0 (2023-07-11)
+------------------
+
+* The ``CONDA_DEVENV_USE_LOCKS`` can be used to change the default value of ``--use-locks``. Useful to set on CI to ensure
+  lock files are being used.
+
 3.1.1 (2023-07-04)
 ------------------
 

docs/usage.rst

@@ -381,6 +381,12 @@ No other changes are required.
 
 You can control if ``devenv`` should use lock files using the ``--use-locks {auto,yes,no}`` command-line option.
 
+.. versionadded:: 3.2.0
+
+The default value for ``--use-locks`` can be set via ``CONDA_DEVENV_USE_LOCKS``, which is useful on CI
+to change the behavior when no explicit option is present in the command line.
+
+
 Updating
 --------
 
@@ -482,7 +488,9 @@ Options
       --use-locks {auto,yes,no}
                             How to use lock files: 'auto' will use them if
                             available, 'yes' will try to use and fail if not
-                            available, 'no' skip lockfiles always.
+                            available, 'no' skip lock files always. Can also be
+                            configured via CONDA_DEVENV_USE_LOCKS environment
+                            variable.
       --update-locks PACKAGE
                             Update the given package in all lock files, while
                             still obeying the pins in the devenv.yml file. Can be

src/conda_devenv/devenv.py

@@ -772,9 +772,12 @@ def parse_args(argv: list[str] | None) -> argparse.Namespace:
     group.add_argument(
         "--use-locks",
         choices=["auto", "yes", "no"],
-        default="auto",
-        help="How to use lock files: 'auto' will use them if available, 'yes' "
-        "will try to use and fail if not available, 'no' skip lockfiles always.",
+        default=os.environ.get("CONDA_DEVENV_USE_LOCKS", "auto"),
+        help=(
+            "How to use lock files: 'auto' will use them if available, 'yes' "
+            "will try to use and fail if not available, 'no' skip lock files always. "
+            "Can also be configured via CONDA_DEVENV_USE_LOCKS environment variable."
+        ),
     )
     group.add_argument(
         "--update-locks",

tests/test_locking.py

@@ -1,6 +1,7 @@
 import sys
 from pathlib import Path
 from textwrap import dedent
+from typing import Literal
 
 import pytest
 
@@ -219,7 +220,7 @@ def test_auto_use_lock_files(
         )
     )
 
-    # Create the env directory because we need it to exist to create the activate/deactive scripts.
+    # Create the env directory because we need it to exist to create the activate/deactivate scripts.
     env_dir = tmp_path / "envs"
     env_dir.joinpath(f"{env_name}/conda-meta").mkdir(parents=True)
     env_dirs = [env_dir]
@@ -242,7 +243,7 @@ def test_auto_use_lock_files(
         ),
     ]
 
-    # Use locks again but create an environment different than the one defined
+    # Use locks again but create an environment different from the one defined
     # in environment.devenv.yml.
     subprocess_call_mock.reset_mock()
     env_dir2 = tmp_path / "envs"
@@ -269,9 +270,20 @@ def test_auto_use_lock_files(
     ]
 
 
+@pytest.mark.parametrize("mode", ["cmd-line", "env-var"])
 def test_use_locks_is_yes_but_no_lock_file(
-    tmp_path: Path, monkeypatch, patch_conda_calls: None, capsys
+    tmp_path: Path,
+    monkeypatch,
+    patch_conda_calls: None,
+    capsys,
+    mode: Literal["cmd-line", "env-var"],
 ) -> None:
+    if mode == "cmd-line":
+        cmdline = ["--use-locks=yes"]
+    else:
+        assert mode == "env-var"
+        monkeypatch.setenv("CONDA_DEVENV_USE_LOCKS", "yes")
+        cmdline = []
     monkeypatch.chdir(tmp_path)
     env_file = tmp_path / "environment.devenv.yml"
     env_file.write_text(
@@ -289,7 +301,7 @@ def test_use_locks_is_yes_but_no_lock_file(
         )
     )
 
-    assert devenv.main(["--use-locks=yes"]) == 2
+    assert devenv.main(cmdline) == 2
     out, err = capsys.readouterr()
     platform = CondaPlatform.current().value
     assert (