[cliptext-] clipstr(): truncate too-wide char into width 1

visidata/cliptext.py

@@ -148,7 +148,16 @@ def _clipstr(s, dispw, trunch='', oddspacech='', combch='', modch=''):
         return '', 0
 
     if dispw == 1:
-        return s[0], 1
+        w_s = dispwidth(s)
+        if w_s > 1:
+            ret = ''
+            for c in s:
+                if dispwidth(ret + c) > 1:
+                    break
+                ret += c
+            return ret, dispwidth(ret)
+        else:
+            return s, w_s
 
     w = 0
     ret = ''

visidata/tests/test_cliptext.py

@@ -19,12 +19,34 @@ def test_dispwidth(self, s, dispw):
         (' jsonl', 5, ' jso…', 5),
         ('abcdで', 6, 'abcdで', 6),
         ('abcdで', 5, 'abcd…', 5),
+        ('a', 1, 'a', 1),
+        ('ab', 1, 'a', 1),
+        ('で', 1, '', 0),
+        ('でで', 1, '', 0),
+        ('', 1, '', 0),
     ])
     def test_clipstr(self, s, w, clippeds, clippedw):
         clips, clipw = visidata.clipstr(s, w)
         assert clips == clippeds
         assert clipw == clippedw
 
+    @pytest.mark.parametrize('s, w, clippeds, clippedw', [
+        ('b to', 4, 'b to', 4),
+        ('abcde', 8, 'abcde', 5),
+        (' jsonl', 5, ' json', 5),
+        ('abcdで', 6, 'abcdで', 6),
+        ('abcdで', 5, 'abcd', 4),
+        ('a', 1, 'a', 1),
+        ('ab', 1, 'a', 1),
+        ('で', 1, '', 0),
+        ('でで', 1, '', 0),
+        ('', 1, '', 0),
+    ])
+    def test_clipstr_no_truncator(self, s, w, clippeds, clippedw):
+        clips, clipw = visidata.clipstr(s, w, truncator='')
+        assert clips == clippeds
+        assert clipw == clippedw
+
     def test_clipdraw_chunks(self):
         prechunks = [
             ('', 'x'),