[3.13] gh-119306: Break up _pyrepl tests (GH-119307) (#119362)

(cherry picked from commit f49df4f486)

Co-authored-by: Eugene Triguba <eugenetriguba@gmail.com>

Lib/test/test_pyrepl/test_reader.py

@@ -0,0 +1,135 @@
+import itertools
+from unittest import TestCase
+
+from .support import handle_all_events, handle_events_narrow_console, code_to_events
+from _pyrepl.console import Event
+
+
+class TestReader(TestCase):
+    def assert_screen_equals(self, reader, expected):
+        actual = reader.calc_screen()
+        expected = expected.split("\n")
+        self.assertListEqual(actual, expected)
+
+    def test_calc_screen_wrap_simple(self):
+        events = code_to_events(10 * "a")
+        reader, _ = handle_events_narrow_console(events)
+        self.assert_screen_equals(reader, f"{9*"a"}\\\na")
+
+    def test_calc_screen_wrap_wide_characters(self):
+        events = code_to_events(8 * "a" + "樂")
+        reader, _ = handle_events_narrow_console(events)
+        self.assert_screen_equals(reader, f"{8*"a"}\\\n樂")
+
+    def test_calc_screen_wrap_three_lines(self):
+        events = code_to_events(20 * "a")
+        reader, _ = handle_events_narrow_console(events)
+        self.assert_screen_equals(reader, f"{9*"a"}\\\n{9*"a"}\\\naa")
+
+    def test_calc_screen_wrap_three_lines_mixed_character(self):
+        # fmt: off
+        code = (
+            "def f():\n"
+           f"  {8*"a"}\n"
+           f"  {5*"樂"}"
+        )
+        # fmt: on
+
+        events = code_to_events(code)
+        reader, _ = handle_events_narrow_console(events)
+
+        # fmt: off
+        self.assert_screen_equals(reader, (
+            "def f():\n"
+           f"  {7*"a"}\\\n"
+            "a\n"
+           f"  {3*"樂"}\\\n"
+            "樂樂"
+        ))
+        # fmt: on
+
+    def test_calc_screen_backspace(self):
+        events = itertools.chain(
+            code_to_events("aaa"),
+            [
+                Event(evt="key", data="backspace", raw=bytearray(b"\x7f")),
+            ],
+        )
+        reader, _ = handle_all_events(events)
+        self.assert_screen_equals(reader, "aa")
+
+    def test_calc_screen_wrap_removes_after_backspace(self):
+        events = itertools.chain(
+            code_to_events(10 * "a"),
+            [
+                Event(evt="key", data="backspace", raw=bytearray(b"\x7f")),
+            ],
+        )
+        reader, _ = handle_events_narrow_console(events)
+        self.assert_screen_equals(reader, 9 * "a")
+
+    def test_calc_screen_backspace_in_second_line_after_wrap(self):
+        events = itertools.chain(
+            code_to_events(11 * "a"),
+            [
+                Event(evt="key", data="backspace", raw=bytearray(b"\x7f")),
+            ],
+        )
+        reader, _ = handle_events_narrow_console(events)
+        self.assert_screen_equals(reader, f"{9*"a"}\\\na")
+
+    def test_setpos_for_xy_simple(self):
+        events = code_to_events("11+11")
+        reader, _ = handle_all_events(events)
+        reader.setpos_from_xy(0, 0)
+        self.assertEqual(reader.pos, 0)
+
+    def test_setpos_from_xy_multiple_lines(self):
+        # fmt: off
+        code = (
+            "def foo():\n"
+            "  return 1"
+        )
+        # fmt: on
+
+        events = code_to_events(code)
+        reader, _ = handle_all_events(events)
+        reader.setpos_from_xy(2, 1)
+        self.assertEqual(reader.pos, 13)
+
+    def test_setpos_from_xy_after_wrap(self):
+        # fmt: off
+        code = (
+            "def foo():\n"
+            "  hello"
+        )
+        # fmt: on
+
+        events = code_to_events(code)
+        reader, _ = handle_events_narrow_console(events)
+        reader.setpos_from_xy(2, 2)
+        self.assertEqual(reader.pos, 13)
+
+    def test_setpos_fromxy_in_wrapped_line(self):
+        # fmt: off
+        code = (
+            "def foo():\n"
+            "  hello"
+        )
+        # fmt: on
+
+        events = code_to_events(code)
+        reader, _ = handle_events_narrow_console(events)
+        reader.setpos_from_xy(0, 1)
+        self.assertEqual(reader.pos, 9)
+
+    def test_up_arrow_after_ctrl_r(self):
+        events = iter(
+            [
+                Event(evt="key", data="\x12", raw=bytearray(b"\x12")),
+                Event(evt="key", data="up", raw=bytearray(b"\x1bOA")),
+            ]
+        )
+
+        reader, _ = handle_all_events(events)
+        self.assert_screen_equals(reader, "")