diff --git a/kitty_tests/diff.py b/kitty_tests/diff.py
deleted file mode 100644
index b99b9f8dd..000000000
--- a/kitty_tests/diff.py
+++ /dev/null
@@ -1,86 +0,0 @@
-#!/usr/bin/env python3
-# License: GPL v3 Copyright: 2018, Kovid Goyal <kovid at kovidgoyal.net>
-
-
-from . import BaseTest
-
-
-class TestDiff(BaseTest):
-
-    def test_changed_center(self):
-        from kittens.diff.diff_speedup import changed_center
-        for left, right, prefix, suffix in [
-                ('abc', 'def', '', ''),
-                ('', 'def', '', ''),
-                ('abc', '', '', ''),
-                ('abc', 'abc', 'abc', ''),
-                ('abc', 'abcdef', 'abc', ''),
-                ('aa111bb', 'aa2bb', 'aa', 'bb'),
-        ]:
-            pc, sc = changed_center(left, right)
-            for src in (left, right):
-                self.assertEqual((prefix, suffix), (src[:pc], src[-sc:] if sc else ''))
-
-    def test_split_with_highlights(self):
-        from kittens.diff.render import Segment, split_with_highlights, truncate_points
-        self.ae(list(truncate_points('1234567890ab', 3)), [3, 6, 9])
-        for line, width, prefix_count, suffix_count, expected in [
-                ('abcdefgh', 20, 2, 3, ('abSScdeEEfgh',)),
-                ('abcdefgh', 20, 2, 0, ('abSScdefghEE',)),
-                ('abcdefgh', 3, 2, 3, ('abSScEE', 'SSdeEEf', 'gh')),
-                ('abcdefgh', 2, 4, 1, ('ab', 'cd', 'SSefEE', 'SSgEEh')),
-        ]:
-            seg = Segment(prefix_count, 'SS')
-            seg.end = len(line) - suffix_count
-            seg.end_code = 'EE'
-            self.ae(expected, tuple(split_with_highlights(line, width, [], seg)))
-
-        def h(s, e, w):
-            ans = Segment(s, f'S{w}S')
-            ans.end = e
-            ans.end_code = f'E{w}E'
-            return ans
-
-        highlights = [h(0, 1, 1), h(1, 3, 2)]
-        self.ae(['S1SaE1ES2SbcE2Ed'], split_with_highlights('abcd', 10, highlights))
-
-    def test_walk(self):
-        import tempfile
-        from pathlib import Path
-
-        from kittens.diff.collect import walk
-
-        with tempfile.TemporaryDirectory() as tmpdir:
-            # /tmp/test/
-            # ├── a
-            # │   └── b
-            # │       └── c
-            # ├── d
-            # ├── #d#
-            # ├── e
-            # ├── e~
-            # └── f
-            # │   └── g
-            # └── h space
-            Path(tmpdir, "a/b").mkdir(parents=True)
-            Path(tmpdir, "a/b/c").touch()
-            Path(tmpdir, "b").touch()
-            Path(tmpdir, "d").touch()
-            Path(tmpdir, "#d#").touch()
-            Path(tmpdir, "e").touch()
-            Path(tmpdir, "e~").touch()
-            Path(tmpdir, "f").mkdir()
-            Path(tmpdir, "f/g").touch()
-            Path(tmpdir, "h space").touch()
-            expected_names = {"d", "e", "f/g", "h space"}
-            expected_pmap = {
-                "d": f"{tmpdir}/d",
-                "e": f"{tmpdir}/e",
-                "f/g": f"{tmpdir}/f/g",
-                "h space": f"{tmpdir}/h space"
-            }
-            names = set()
-            pmap = {}
-            walk(tmpdir, names, pmap, ("*~", "#*#", "b"))
-            self.ae(expected_names, names)
-            self.ae(expected_pmap, pmap)