Merge pull request 'pkgs/clan: Add flake validation to clan show' (#4352) from kenji/ke-non-clan-show into main

Reviewed-on: https://git.clan.lol/clan/clan-core/pulls/4352

pkgs/clan-cli/clan_cli/clan/show.py

@@ -2,13 +2,13 @@ import argparse
 import logging
 
 from clan_lib.clan.get import get_clan_details
-from clan_lib.flake import Flake
+from clan_lib.flake import require_flake
 
 log = logging.getLogger(__name__)
 
 
 def show_command(args: argparse.Namespace) -> None:
-    flake: Flake = args.flake
+    flake = require_flake(args.flake)
     meta = get_clan_details(flake)
 
     print(f"Name: {meta.get('name')}")

pkgs/clan-cli/clan_cli/clan/show_test.py

@@ -1,4 +1,7 @@
+from pathlib import Path
+
 import pytest
+from clan_lib.errors import ClanError
 
 from clan_cli.tests.fixtures_flakes import FlakeForTest
 from clan_cli.tests.helpers import cli
@@ -14,3 +17,19 @@ def test_clan_show(
     assert "Name:" in output.out
     assert "Name: test_flake_with_core" in output.out
     assert "Description:" in output.out
+
+
+def test_clan_show_no_flake(
+    tmp_path: Path, monkeypatch: pytest.MonkeyPatch, capture_output: CaptureOutput
+) -> None:
+    monkeypatch.chdir(tmp_path)
+
+    with pytest.raises(ClanError) as exc_info:
+        cli.run(["show"])
+
+    assert "No clan flake found in the current directory or its parents" in str(
+        exc_info.value
+    )
+    assert "Use the --flake flag to specify a clan flake path or URL" in str(
+        exc_info.value
+    )

pkgs/clan-cli/clan_lib/flake/__init__.py

@@ -1 +1 @@
-from .flake import Flake  # noqa
+from .flake import Flake, require_flake  # noqa

pkgs/clan-cli/clan_lib/flake/flake.py

@@ -931,3 +931,28 @@ class Flake:
 
         full_selector = f'clanInternals.machines."{system}"."{machine_name}".{selector}'
         return self.select(full_selector)
+
+
+def require_flake(flake: Flake | None) -> Flake:
+    """
+    Require that a flake argument is provided, if not in a clan flake.
+
+    This should be called by commands that require a flake but don't have
+    a sensible default when no clan flake is found locally.
+
+    Args:
+        flake: The flake object to check, may be None
+
+    Returns:
+        The validated flake object
+
+    Raises:
+        ClanError: If the flake is None
+    """
+    if flake is None:
+        msg = "No clan flake found in the current directory or its parents"
+        raise ClanError(
+            msg,
+            description="Use the --flake flag to specify a clan flake path or URL",
+        )
+    return flake