handle empty list in table formatter

If there is no data to be formatted, don't try to make sure it fits in
the width of the terminal because we're not going to be writing anything
anyway.

Closes-Bug: #1539770
Change-Id: I877bad1be7a074fccc03f0327b0e43f1e125246c
Signed-off-by: Doug Hellmann <doug@doughellmann.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/cliff/tests/test_formatters_table.py b/cliff/tests/test_formatters_table.py
index 711ab6b..84ec571 100644
--- a/cliff/tests/test_formatters_table.py
+++ b/cliff/tests/test_formatters_table.py
@@ -227,6 +227,20 @@ def test_table_list_formatter_max_width(tw):
     assert len(actual.splitlines()[0]) == expected_width
 
 
+@mock.patch('cliff.utils.terminal_width')
+def test_table_list_formatter_empty(tw):
+    tw.return_value = 80
+    sf = table.TableFormatter()
+    c = ('a', 'b', 'c')
+    data = []
+    expected = '\n'
+    output = StringIO()
+    parsed_args = args()
+    sf.emit_list(c, data, output, parsed_args)
+    actual = output.getvalue()
+    assert expected == actual
+
+
 def test_field_widths():
     tf = table.TableFormatter
     assert {