fix: setuptools-less installs couldn't translate, add test

.github/workflows/ci.yml

@@ -59,6 +59,10 @@ jobs:
         python-version: ${{ matrix.python-version }}
         allow-prereleases: true
 
+    - name: Add locale for locale test
+      if: runner.os == 'Linux' && matrix.python-version != '3.10'
+      run: sudo locale-gen fr_FR.UTF-8
+
     - name: Setup uv (cached)
       uses: hynek/setup-cached-uv@v2
 

plumbum/cli/i18n.py

@@ -1,6 +1,9 @@
 from __future__ import annotations
 
 import locale
+import os
+
+DIR = os.path.abspath(os.path.dirname(__file__))
 
 # High performance method for English (no translation needed)
 loc = locale.getlocale()[0]
@@ -23,33 +26,33 @@ def get_translation_for(
 
 else:
     import gettext
-    import os
 
     # If not installed with setuptools, this might not be available
     try:
         import pkg_resources
     except ImportError:
         pkg_resources = None  # type: ignore[assignment]
 
-    local_dir = os.path.basename(__file__)
-
     def get_translation_for(package_name: str) -> gettext.NullTranslations:  # type: ignore[misc]
         """Find and return gettext translation for package
         (Try to find folder manually if setuptools does not exist)
         """
+        assert loc is not None
 
         if "." in package_name:
             package_name = ".".join(package_name.split(".")[:-1])
         localedir = None
 
         if pkg_resources is None:
-            mydir = os.path.join(local_dir, "i18n")
+            mydir = os.path.join(DIR, "i18n")
         else:
             mydir = pkg_resources.resource_filename(package_name, "i18n")
 
         for localedir in mydir, None:
-            localefile = gettext.find(package_name, localedir)
+            localefile = gettext.find(package_name, localedir, languages=[loc])
             if localefile:
                 break
 
-        return gettext.translation(package_name, localedir=localedir, fallback=True)
+        return gettext.translation(
+            package_name, localedir=localedir, languages=[loc], fallback=True
+        )

tests/test_translate.py

@@ -0,0 +1,61 @@
+# Setting French as system language
+from __future__ import annotations
+
+import importlib
+import locale
+
+import pytest
+
+import plumbum.cli
+import plumbum.cli.i18n
+
+
+def reload_cli():
+    importlib.reload(plumbum.cli.i18n)
+    importlib.reload(plumbum.cli.switches)
+    importlib.reload(plumbum.cli.application)
+    importlib.reload(plumbum.cli)
+
+
+@pytest.fixture()
+def french():
+    try:
+        locale.setlocale(locale.LC_ALL, "fr_FR.utf-8")
+        reload_cli()
+        yield
+    except locale.Error:
+        pytest.skip(
+            "No fr_FR locale found, run 'sudo locale-gen fr_FR.UTF-8' to run this test"
+        )
+    finally:
+        locale.setlocale(locale.LC_ALL, "")
+        reload_cli()
+
+
+@pytest.mark.usefixtures("french")
+def test_nolang_switches():
+    class Simple(plumbum.cli.Application):
+        foo = plumbum.cli.SwitchAttr("--foo")
+
+        def main(self):
+            pass
+
+    _, rc = Simple.run(["foo", "-h"], exit=False)
+    assert rc == 0
+    _, rc = Simple.run(["foo", "--version"], exit=False)
+    assert rc == 0
+
+
+@pytest.mark.usefixtures("french")
+def test_help_lang(capsys):
+    class Simple(plumbum.cli.Application):
+        foo = plumbum.cli.SwitchAttr("--foo")
+
+        def main(self):
+            pass
+
+    _, rc = Simple.run(["foo", "-h"], exit=False)
+    assert rc == 0
+    stdout, stderr = capsys.readouterr()
+    assert "Utilisation" in stdout
+    assert "Imprime ce message d'aide et sort" in stdout