tests: add smoke coverage for shell completion script

test/unit/test_shell_completion.py

@@ -0,0 +1,58 @@
+import os
+import shlex
+import subprocess
+import tempfile
+
+
+def test_metaflow_completion_script_smoke():
+    """Smoke-test that bash completion loads and returns command candidates."""
+    repo_root = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", ".."))
+    completion_script = os.path.join(repo_root, "metaflow-complete.sh")
+
+    # Use a temporary executable named `metaflow` so click reads _METAFLOW_COMPLETE.
+    wrapper_code = (
+        "#!/usr/bin/env python3\n"
+        "import os\n"
+        "import sys\n"
+        f"sys.path.insert(0, {repr(repo_root)})\n"
+        "from metaflow.cmd.main_cli import start\n"
+        "start()\n"
+    )
+
+    wrapper_path = None
+    try:
+        fd, wrapper_path = tempfile.mkstemp(prefix="metaflow-cli-", dir=repo_root)
+        with os.fdopen(fd, "w") as f:
+            f.write(wrapper_code)
+        os.chmod(wrapper_path, 0o755)
+
+        bash_script = f"""
+set -euo pipefail
+source {shlex.quote(completion_script)}
+complete -p metaflow >/dev/null
+COMP_WORDS=("metaflow" "")
+COMP_CWORD=1
+_metaflow_completion {shlex.quote(wrapper_path)}
+printf "%s\\n" "${{COMPREPLY[@]}}"
+"""
+        result = subprocess.run(
+            ["bash", "-c", bash_script],
+            capture_output=True,
+            text=True,
+            check=True,
+            env={**os.environ, "PYTHONPATH": repo_root},
+        )
+    finally:
+        if wrapper_path is not None:
+            try:
+                os.remove(wrapper_path)
+            except OSError:
+                pass
+
+    completions = {line.strip() for line in result.stdout.splitlines() if line.strip()}
+    expected_commands = {"configure", "develop", "help", "status", "tutorials", "code"}
+    missing = expected_commands - completions
+    assert not missing, (
+        "metaflow completion output is missing expected commands: "
+        f"{sorted(missing)}. Full output: {sorted(completions)}"
+    )