test: compare command help against whitespace-normalized output

The fetch-and-pack help description is long enough that Click wraps it across
lines in `--help` output, so the raw single-line help string was no longer a
substring of the output and `test_command_help` failed. Collapse whitespace on
both sides before the substring check so the assertion is insensitive to
terminal-width line wrapping.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: mihow

tests/dataset_tools/test_cli.py

@@ -1,8 +1,22 @@
+import re
+
 import pytest
 from click.testing import CliRunner
 
 from src.dataset_tools.cli import COMMAND_KEYS, COMMANDS, COMMANDS_HELP, cli
 
+
+def _normalize_ws(text: str) -> str:
+    """Collapse runs of whitespace to a single space.
+
+    Click wraps long help text across lines based on terminal width, so the
+    raw ``--help`` output cannot be compared directly against the single-line
+    help strings. Normalising whitespace on both sides makes the comparison
+    insensitive to line wrapping.
+    """
+    return re.sub(r"\s+", " ", text).strip()
+
+
 command_test_parameters = [COMMANDS[cmd_key] for cmd_key in COMMAND_KEYS]
 command_and_help_test_parameters = [
     (COMMANDS[cmd_key], COMMANDS_HELP[cmd_key]) for cmd_key in COMMAND_KEYS
@@ -31,7 +45,7 @@ def test_command_help(command, command_help):
     result = runner.invoke(cli, [command, "--help"])
     assert result.exit_code == 0
     assert command in result.output
-    assert command_help in result.output
+    assert _normalize_ws(command_help) in _normalize_ws(result.output)
 
 
 def test_number_of_command_constants():