test: regression test for #305

Verify that `source uv_env_setup.sh INVALID` does not kill the
user's shell (uses return instead of exit).

Author: zaz

test/test_uv_env_setup.py

@@ -0,0 +1,26 @@
+"""Tests for uv_env_setup.sh error handling."""
+
+import subprocess
+from pathlib import Path
+
+
+def test_source_invalid_platform_does_not_kill_shell():
+    """Verify sourcing with invalid platform does not kill the shell.
+
+    If the script uses bare `exit 1`, sourcing it kills the shell
+    (subshell exits). If it uses `return 1`, the subshell survives
+    and the sentinel `STILL_ALIVE` is printed.
+    """
+    script = Path(__file__).parents[1] / "uv_env_setup.sh"
+    result = subprocess.run(
+        [
+            "bash",
+            "-c",
+            f"source {script} INVALID 2>/dev/null; echo STILL_ALIVE",
+        ],
+        capture_output=True,
+        text=True,
+    )
+    assert "STILL_ALIVE" in result.stdout, (
+        "Shell was killed by `exit 1` instead of `return 1`"
+    )