gh-121499: Fix multi-line history rendering in the REPL

Signed-off-by: Pablo Galindo <[email protected]>

Author: pablogsal

Lib/_pyrepl/historical_reader.py

@@ -264,6 +264,7 @@ def select_item(self, i: int) -> None:
         self.historyi = i
         self.pos = len(self.buffer)
         self.dirty = True
+        self.last_refresh_cache.invalidated = True
 
     def get_item(self, i: int) -> str:
         if i != len(self.history):

Lib/test/test_pyrepl/support.py

@@ -38,6 +38,16 @@ def code_to_events(code: str):
         yield Event(evt="key", data=c, raw=bytearray(c.encode("utf-8")))
 
 
+def clean_screen(screen: Iterable[str]):
+    """Cleans color and console characters out of a screen output.
+
+    This is useful for screen testing, it increases the test readability since
+    it strips out all the unreadable side of the screen.
+    """
+    return '\n'.join(screen).replace(
+        '\x1b[1;35m>>>\x1b[0m', '').replace('\x1b[1;35m...\x1b[0m', '').strip()
+
+
 def prepare_reader(console: Console, **kwargs):
     config = ReadlineConfig(readline_completer=kwargs.pop("readline_completer", None))
     reader = ReadlineAlikeReader(console=console, config=config)

Lib/test/test_pyrepl/test_pyrepl.py

@@ -21,6 +21,7 @@
     more_lines,
     multiline_input,
     code_to_events,
+    clean_screen
 )
 from _pyrepl.console import Event
 from _pyrepl.readline import ReadlineAlikeReader, ReadlineConfig
@@ -490,6 +491,7 @@ def test_basic(self):
 
         output = multiline_input(reader)
         self.assertEqual(output, "1+1")
+        self.assertEqual(clean_screen(reader.screen), "1+1")
 
     def test_multiline_edit(self):
         events = itertools.chain(
@@ -519,8 +521,10 @@ def test_multiline_edit(self):
 
         output = multiline_input(reader)
         self.assertEqual(output, "def f():\n    ...\n    ")
+        self.assertEqual(clean_screen(reader.screen), "def f():\n    ...")
         output = multiline_input(reader)
         self.assertEqual(output, "def g():\n    pass\n    ")
+        self.assertEqual(clean_screen(reader.screen), "def g():\n    pass")
 
     def test_history_navigation_with_up_arrow(self):
         events = itertools.chain(
@@ -539,12 +543,40 @@ def test_history_navigation_with_up_arrow(self):
 
         output = multiline_input(reader)
         self.assertEqual(output, "1+1")
+        self.assertEqual(clean_screen(reader.screen), "1+1")
         output = multiline_input(reader)
         self.assertEqual(output, "2+2")
+        self.assertEqual(clean_screen(reader.screen), "2+2")
         output = multiline_input(reader)
         self.assertEqual(output, "2+2")
+        self.assertEqual(clean_screen(reader.screen), "2+2")
         output = multiline_input(reader)
         self.assertEqual(output, "1+1")
+        self.assertEqual(clean_screen(reader.screen), "1+1")
+
+    def test_history_with_multiline_entries(self):
+        code = "def foo():\nx = 1\ny = 2\nz = 3\n\ndef bar():\nreturn 42\n\n"
+        events = list(itertools.chain(
+            code_to_events(code),
+            [
+                Event(evt="key", data="up", raw=bytearray(b"\x1bOA")),
+                Event(evt="key", data="up", raw=bytearray(b"\x1bOA")),
+                Event(evt="key", data="up", raw=bytearray(b"\x1bOA")),
+                Event(evt="key", data="\n", raw=bytearray(b"\n")),
+                Event(evt="key", data="\n", raw=bytearray(b"\n")),
+            ]
+        ))
+
+        reader = self.prepare_reader(events)
+        output = multiline_input(reader)
+        output = multiline_input(reader)
+        output = multiline_input(reader)
+        self.assertEqual(
+            clean_screen(reader.screen),
+            'def foo():\n    x = 1\n    y = 2\n    z = 3'
+        )
+        self.assertEqual(output, "def foo():\n    x = 1\n    y = 2\n    z = 3\n    ")
+
 
     def test_history_navigation_with_down_arrow(self):
         events = itertools.chain(
@@ -562,6 +594,7 @@ def test_history_navigation_with_down_arrow(self):
 
         output = multiline_input(reader)
         self.assertEqual(output, "1+1")
+        self.assertEqual(clean_screen(reader.screen), "1+1")
 
     def test_history_search(self):
         events = itertools.chain(
@@ -578,18 +611,23 @@ def test_history_search(self):
 
         output = multiline_input(reader)
         self.assertEqual(output, "1+1")
+        self.assertEqual(clean_screen(reader.screen), "1+1")
         output = multiline_input(reader)
         self.assertEqual(output, "2+2")
+        self.assertEqual(clean_screen(reader.screen), "2+2")
         output = multiline_input(reader)
         self.assertEqual(output, "3+3")
+        self.assertEqual(clean_screen(reader.screen), "3+3")
         output = multiline_input(reader)
         self.assertEqual(output, "1+1")
+        self.assertEqual(clean_screen(reader.screen), "1+1")
 
     def test_control_character(self):
         events = code_to_events("c\x1d\n")
         reader = self.prepare_reader(events)
         output = multiline_input(reader)
         self.assertEqual(output, "c\x1d")
+        self.assertEqual(clean_screen(reader.screen), "c")
 
 
 class TestPyReplCompleter(TestCase):

Misc/NEWS.d/next/Core and Builtins/2024-07-09-13-53-18.gh-issue-121499.rpp7il.rst

@@ -0,0 +1,2 @@
+Fix a bug affecting how multi-line history was being rendered in the new
+REPL after interacting with the new screen cache. Patch by Pablo Galindo