Fix list-table width test breaking pytest reporting

The width test replaced the global shutil.get_terminal_size with a
no-argument lambda, so pytest's own get_terminal_size(fallback=...)
call during progress reporting raised TypeError and aborted the run
with an INTERNALERROR.

Extract a _list_table_width() helper and test it directly with a
signature-compatible stub, so the cap logic is verified without
disturbing pytest's terminal-size lookups.

Author: AndrewSazonov

src/easydiffraction/utils/utils.py

@@ -945,6 +945,11 @@ def _tutorial_url_for_format(url: str, fmt: TutorialFormat) -> str:
 _LIST_TABLE_MAX_WIDTH = 100
 
 
+def _list_table_width() -> int:
+    """Return the listing-table width, capped at the maximum."""
+    return min(shutil.get_terminal_size().columns, _LIST_TABLE_MAX_WIDTH)
+
+
 def list_tutorials() -> None:
     """
     Display a table of available tutorial notebooks.
@@ -989,7 +994,7 @@ def list_tutorials() -> None:
         columns_headers=columns_headers,
         columns_data=columns_data,
         columns_alignment=columns_alignment,
-        width=min(shutil.get_terminal_size().columns, _LIST_TABLE_MAX_WIDTH),
+        width=_list_table_width(),
     )
 
 

tests/unit/easydiffraction/utils/test_utils.py

@@ -356,21 +356,17 @@ def test_list_tutorials_with_data(monkeypatch, capsys):
     ('terminal_columns', 'expected_width'),
     [(200, 100), (72, 72)],
 )
-def test_list_tutorials_caps_table_width(monkeypatch, terminal_columns, expected_width):
+def test_list_table_width_caps_at_max(monkeypatch, terminal_columns, expected_width):
     import easydiffraction.utils.utils as MUT
 
-    fake_index = {'quick-start': {'url': 'https://x/{version}/t/quick-start.ipynb'}}
-    monkeypatch.setattr(MUT, '_fetch_tutorials_index', lambda: fake_index)
-    monkeypatch.setattr(MUT, 'package_version', lambda name: '0.8.0')
+    # Accept arbitrary args so pytest's own ``get_terminal_size(fallback=...)``
+    # keeps working while this patch is active.
     monkeypatch.setattr(
-        MUT.shutil, 'get_terminal_size', lambda: os.terminal_size((terminal_columns, 24))
+        MUT.shutil,
+        'get_terminal_size',
+        lambda *args, **kwargs: os.terminal_size((terminal_columns, 24)),
     )
-
-    captured = {}
-    monkeypatch.setattr(MUT, 'render_table', lambda **kwargs: captured.update(kwargs))
-
-    MUT.list_tutorials()
-    assert captured['width'] == expected_width
+    assert MUT._list_table_width() == expected_width
 
 
 def test_download_tutorial_unknown_id(monkeypatch):