Start work on testing multicell commands

kitty_tests/multicell.py

@@ -0,0 +1,63 @@
+#!/usr/bin/env python
+# License: GPLv3 Copyright: 2024, Kovid Goyal <kovid at kovidgoyal.net>
+
+
+from kitty.fast_data_types import TEXT_SIZE_CODE, Screen
+
+from . import BaseTest, parse_bytes
+
+
+class TestMulticell(BaseTest):
+
+    def test_multicell(self):
+        test_multicell(self)
+
+
+def multicell(screen: Screen, text: str, width: int = 0, scale: int = 1, subscale: int = 0) -> None:
+    cmd = f'\x1b]{TEXT_SIZE_CODE};w={width}:s={scale}:f={subscale};{text}\a'
+    parse_bytes(screen, cmd.encode())
+
+
+def test_multicell(self: TestMulticell) -> None:
+
+    def ac(x_, y_, **assertions):  # assert cell
+        cell = s.cpu_cells(y_, x_)
+        msg = f'Assertion failed for cell at ({x_}, {y_})\n{cell}\n'
+        if 'is_multicell' in assertions:
+            if assertions['is_multicell']:
+                assert cell['mcd'] is not None, msg
+            else:
+                assert cell['mcd'] is None, msg
+        def ae(key):
+            if key not in assertions:
+                return
+            if key in cell:
+                val = cell[key]
+            else:
+                mcd = cell['mcd']
+                if mcd is None:
+                    raise AssertionError(f'{msg}Unexpectedly not a multicell')
+                val = mcd[key]
+            assert assertions[key] == val, f'{msg}{assertions[key]!r} != {val!r}'
+
+        ae('x')
+        ae('y')
+        ae('width')
+        ae('scale')
+        ae('subscale')
+        ae('vertical_align')
+        ae('text')
+        ae('explicitly_set')
+        if 'cursor' in assertions:
+            self.ae(assertions['cursor'], (s.cursor.x, s.cursor.y), msg)
+
+    s = self.create_screen(cols=5, lines=5)
+    ac(0, 0, is_multicell=False)
+    multicell(s, 'a')
+    ac(0, 0, is_multicell=True, width=1, scale=1, subscale=0, x=0, y=0, text='a', explicitly_set=True, cursor=(1, 0))
+    ac(0, 1, is_multicell=False), ac(1, 0, is_multicell=False), ac(1, 1, is_multicell=False)
+    s.draw('莊')
+    ac(0, 0, is_multicell=True, width=1, scale=1, subscale=0, x=0, y=0, text='a', explicitly_set=True)
+    ac(1, 0, is_multicell=True, width=2, scale=1, subscale=0, x=0, y=0, text='莊', explicitly_set=False, cursor=(3, 0))
+    ac(2, 0, is_multicell=True, width=2, scale=1, subscale=0, x=1, y=0, text='', explicitly_set=False)
+    ac(1, 0, is_multicell=False), ac(1, 1, is_multicell=False)