fix: japanese characters not truncated correctly in tui terminal output

1 files changed, 11 insertions, 0 deletions

diff --git a/app/tests/test_runview.py b/app/tests/test_runview.py
index 8feeee1..3f77ed0 100644
--- a/app/tests/test_runview.py
+++ b/app/tests/test_runview.py
@@ -62,10 +62,21 @@ class FormatTests(_FakeTui, unittest.TestCase):
         self.assertEqual(runview._fit("hello", 3), "he~")
         self.assertEqual(runview._fit("hi", 10), "hi")
 
+    def test_fit_truncates_wide_characters_by_display_columns(self):
+        # Japanese characters fill two terminal cells each, so fitting
+        # by character count would let lines overflow their pane.
+        self.assertEqual(runview._fit("你好", 4), "你好")
+        self.assertEqual(runview._fit("你好你好", 5), "你好~")
+        self.assertEqual(runview._fit("こんにちは", 3), "こ~")
+
     def test_wrap_wraps_on_word_boundaries(self):
         self.assertEqual(runview._wrap("aaaa bbbb cccc dddd", 12),
                          ["aaaa bbbb", "cccc dddd"])
 
+    def test_wrap_counts_wide_characters_as_two_columns(self):
+        self.assertEqual(runview._wrap("日本語 テスト", 10),
+                         ["日本語", "テスト"])
+
 
 class StateTransitionTests(_FakeTui, unittest.TestCase):
     def test_boot_flow_starting_to_ready(self):