a818be1ed4
* fix: preserve reader scroll intent during live renders * fix: enforce programmatic scroll guard freshness * test: update programmatic scroll guard assertion * test: update scroll safety valve assertion * fix: reconcile scroll intent helper after base refresh * fix: timestamp fallback history scroll writes * test: cover stale older-message fallback scroll guard * test: execute the real slow-render history fallback * test: provide the history fallback DOM helper * test: retain async declaration in history fallback harness * test: remove trailing blank line from scroll intent regression * test(#6414): update scroll-intent harness for window._autoScrollFollow + _messageScrollInputGeneration (master drift) * Release exp-v0.52.172: preserve reader scroll intent during live renders (#6453) --------- Co-authored-by: Frank Song <franksong2702@gmail.com> Co-authored-by: Frank Song <xuefu.song@qq.com> Co-authored-by: nesquena-hermes <nesquena-hermes@users.noreply.github.com>
813 lines
38 KiB
Python
813 lines
38 KiB
Python
"""Regression tests for the issue #5637 streaming stale-anchor guards.
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Once the reader is up in history during a live stream, the anchor captured for a
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same-frame restore goes stale as the streaming chunk grows content ABOVE the viewport:
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the anchor's captured topOffset (and the absolute snapshot.top) no longer map to the
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same content, so realigning to them yanks a still reader backward by a few hundred px.
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The existing `snapshot.userUnpinned===true` fallback skip is defeated because the
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scrollHeight-collapse scroll event re-pins the state machine (flips userUnpinned back to
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false) mid-stream.
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Two guards close this, both keyed on content-growth-since-capture + absence of real
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input intent (NOT a scrollTop diff, which the browser's own overflow-anchor writes on an
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overflow-anchor:auto container):
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1. `_restoreMessageViewportAnchor` refuses the realign write.
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2. the absolute `snapshot.top` fallback in `_restoreMessageScrollSnapshotSameFrame`
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refuses its write.
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Every behavioral test below is designed to FAIL on the pre-guard code and PASS only with
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the guard. Node-harness pattern (extractFunc + mock DOM) shared with the sibling scroll
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regression suites.
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"""
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import json
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import pathlib
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import shutil
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import subprocess
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import tempfile
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import pytest
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ROOT = pathlib.Path(__file__).parent.parent
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UI_JS_PATH = ROOT / "static" / "ui.js"
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NODE = shutil.which("node")
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pytestmark = pytest.mark.skipif(NODE is None, reason="node not on PATH")
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def _run_node(source: str) -> str:
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with tempfile.NamedTemporaryFile(
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"w", suffix=".cjs", encoding="utf-8", dir=ROOT, delete=False
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) as script:
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script.write(source)
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script_path = pathlib.Path(script.name)
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try:
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result = subprocess.run(
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[NODE, str(script_path)], cwd=str(ROOT),
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capture_output=True, text=True, timeout=30,
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)
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finally:
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script_path.unlink(missing_ok=True)
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if result.returncode != 0:
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raise RuntimeError(result.stderr)
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return result.stdout.strip()
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def _extract_js_function(js: str, name: str) -> str:
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"""Extract a production function without runtime eval/source execution."""
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marker = f"function {name}("
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start = js.index(marker)
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brace = js.index("{", start)
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depth = 0
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quote = None
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escaped = False
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line_comment = False
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block_comment = False
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index = brace
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while index < len(js):
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char = js[index]
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next_char = js[index + 1] if index + 1 < len(js) else ""
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if line_comment:
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if char == "\n":
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line_comment = False
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index += 1
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continue
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if block_comment:
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if char == "*" and next_char == "/":
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block_comment = False
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index += 2
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continue
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index += 1
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continue
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if quote:
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if escaped:
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escaped = False
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elif char == "\\":
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escaped = True
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elif char == quote:
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quote = None
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index += 1
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continue
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if char == "/" and next_char == "/":
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line_comment = True
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index += 2
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continue
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if char == "/" and next_char == "*":
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block_comment = True
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index += 2
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continue
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if char in "'\"`":
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quote = char
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index += 1
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continue
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if char == "{":
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depth += 1
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elif char == "}":
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depth -= 1
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if depth == 0:
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return js[start : index + 1]
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index += 1
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raise AssertionError(f"JavaScript function {name} did not close")
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def _live_render_ownership_harness(*, move_to_bottom: bool) -> str:
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"""Compose real input production with the production queued live-render restore."""
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js = UI_JS_PATH.read_text(encoding="utf-8")
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functions = [
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"renderLiveAnchorActivityScene",
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"_freshProgrammaticScrollActive",
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"_recordNonMessageScrollIntent",
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"_captureMessageScrollSnapshot",
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"_messageScrollSnapshotInputChanged",
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"_abandonMessageScrollSnapshot",
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"_restorePinnedMessageScrollSnapshot",
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"_restoreMessageScrollSnapshotSameFrame",
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"_prepareLiveAnchorScrollRebuildGuard",
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"_restoreLiveAnchorScrollSnapshotAfterRebuild",
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]
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production = "\n".join(_extract_js_function(js, name) for name in functions)
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target_delta = 100 if move_to_bottom else -100
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final_top = 90026 if move_to_bottom else 89000
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return production + f"""
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const PROGRAMMATIC_SCROLL_VALID_MS=150;
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let writes=[];
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let _messageScrollInputGeneration=0;
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let _messageUserUnpinned={str(move_to_bottom).lower()};
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let _scrollPinned={str(not move_to_bottom).lower()};
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let _nearBottomCount=0;
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let _lastScrollTop=null, _lastMessageClientHeight=null;
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let _programmaticScroll=false, _programmaticScrollSetAt=0;
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let recordWrites=true;
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const callbacks=[];
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const performance={{now(){{return 1;}}}};
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const el={{
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scrollHeight:90453, clientHeight:427,
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get scrollTop(){{return this._top;}},
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set scrollTop(value){{if(recordWrites) writes.push(Math.round(value)); this._top=value;}},
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_top:{'89577' if move_to_bottom else '90026'},
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contains(target){{return target===this;}},
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querySelector(){{return null;}},
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}};
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const document={{getElementById(id){{return id==='messages'?el:null;}}}};
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const msgInner={{style:{{}},dataset:{{}}}};
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const emptyState={{style:{{display:''}}}};
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const turn={{
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dataset:{{}},
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setAttribute(){{}},
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querySelectorAll(){{return [];}},
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}};
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const blocks={{querySelectorAll(){{return [];}}}};
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function $(id){{
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if(id==='messages') return el;
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if(id==='msgInner') return msgInner;
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if(id==='emptyState') return emptyState;
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if(id==='liveAssistantTurn') return turn;
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return null;
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}}
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function _captureMessageViewportAnchor(){{return null;}}
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function _shouldFollowMessagesOnDomReplace(){{return true;}}
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function _deferClearProgrammaticScroll(){{}}
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function _cancelBottomSettle(){{}}
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function _restoreMessageViewportAnchor(){{return false;}}
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function _remountMessageViewportAnchor(){{return false;}}
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function _desktopAnchorRealignDelta(){{return null;}}
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function _isTouchLikeMessageViewport(){{return false;}}
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function _recentMessageScrollIntent(){{return false;}}
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function _recentMessageTouchScrollIntent(){{return false;}}
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function _restoreMessageScrollSnapshotSameFrameFallback(){{}}
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function requestAnimationFrame(callback){{callbacks.push(callback);}}
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function chatActivityMode(){{return 'compact_worklog';}}
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function isSimplifiedToolCalling(){{return true;}}
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const S={{session:{{session_id:'sid-1',pending_started_at:1}},activeStreamId:'stream-1'}};
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function _anchorSceneRowsForRendering(){{return [];}}
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function _assistantTurnBlocks(){{return blocks;}}
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function _captureWorklogDetailDisclosureState(){{return null;}}
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function _anchorSceneWorklogGroup(){{return {{}};}}
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function _renderAnchorSceneRowsIntoWorklog(){{return true;}}
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function _restoreWorklogDetailDisclosureState(){{}}
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function _startActivityElapsedTimer(){{}}
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function _dedupeLiveProcessedWorklogAnchors(){{}}
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function _moveLiveRunStatusToTurnEnd(){{}}
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function scrollIfPinned(){{}}
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const rendered=renderLiveAnchorActivityScene('stream-1',{{activity_rows:[]}},{{sessionId:'sid-1'}});
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const initialWrites=writes.slice();
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writes=[];
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const guardQueued=callbacks.length>0;
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recordWrites=false;
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_recordNonMessageScrollIntent({{target:el,deltaY:{target_delta}}});
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el.scrollTop={final_top};
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recordWrites=true;
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callbacks.shift()();
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console.log(JSON.stringify({{rendered,guardQueued,initialWrites,writes, finalScrollTop:el.scrollTop,
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messageUserUnpinned:_messageUserUnpinned, scrollPinned:_scrollPinned,
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generation:_messageScrollInputGeneration}}));
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"""
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def test_live_render_queue_preserves_real_upward_input_from_pinned_capture():
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"""The real producer and queued live-render callback preserve upward input."""
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result = json.loads(_run_node(_live_render_ownership_harness(move_to_bottom=False)))
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assert result == {
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"rendered": True,
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"guardQueued": True,
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"initialWrites": [90026],
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"writes": [],
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"finalScrollTop": 89000,
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"messageUserUnpinned": True,
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"scrollPinned": False,
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"generation": 1,
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}
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def test_live_render_queue_repins_real_downward_input_at_bottom():
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"""The real producer and queued live-render callback re-pin at true bottom."""
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result = json.loads(_run_node(_live_render_ownership_harness(move_to_bottom=True)))
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assert result == {
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"rendered": True,
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"guardQueued": True,
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"initialWrites": [89577],
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"writes": [],
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"finalScrollTop": 90026,
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"messageUserUnpinned": False,
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"scrollPinned": True,
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"generation": 1,
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}
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def _extract_func_script(js: str) -> str:
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prelude = "const src = " + json.dumps(js) + ";\n"
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body = r"""
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function extractFunc(name) {
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const re = new RegExp('function\\s+' + name + '\\s*\\(');
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const start = src.search(re);
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if (start < 0) throw new Error(name + ' not found');
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let i = src.indexOf('{', start);
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let depth = 1; i++;
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let str = null, inLine = false, inBlock = false, inRegex = false, prev = '';
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while (depth > 0 && i < src.length) {
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const c = src[i], n = src[i + 1];
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if (inLine) { if (c === '\n') inLine = false; i++; continue; }
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if (inBlock) { if (c === '*' && n === '/') { inBlock = false; i++; } i++; continue; }
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if (str) { if (c === '\\') { i += 2; continue; } if (c === str) str = null; i++; continue; }
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if (inRegex) { if (c === '\\') { i += 2; continue; } if (c === '/') inRegex = false; i++; continue; }
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if (c === '/' && n === '/') { inLine = true; i += 2; continue; }
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if (c === '/' && n === '*') { inBlock = true; i += 2; continue; }
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if (c === '"' || c === "'" || c === '`') { str = c; i++; continue; }
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if (c === '/' && !'})]0123456789'.includes(prev) && !/[A-Za-z_$]/.test(prev)) { inRegex = true; i++; continue; }
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if (c === '{') depth++; else if (c === '}') depth--;
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if (c.trim()) prev = c;
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i++;
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}
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return src.slice(start, i);
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}"""
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return prelude + body
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# ---- realign guard (_restoreMessageViewportAnchor) -------------------------------
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def _realign_harness(*, anchor_extra: str, cur_scroll_height: int, rect_top: int,
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top_offset: int, active_intent: bool = False,
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touch_like: bool = True) -> str:
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js = UI_JS_PATH.read_text(encoding="utf-8")
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intent_js = "true" if active_intent else "false"
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touch_js = "true" if touch_like else "false"
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return _extract_func_script(js) + f"""
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let writes = [];
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let stTop = 90030;
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const row = {{ getBoundingClientRect(){{ return {{ top: {rect_top} }}; }},
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getClientRects(){{ return [{{}}]; }}, dataset: {{ messageAnchorKey: 'k1' }} }};
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const container = {{
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get scrollTop(){{ return stTop; }}, set scrollTop(v){{ writes.push(Math.round(v)); stTop = v; }},
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scrollHeight: {cur_scroll_height}, clientHeight: 427,
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getBoundingClientRect(){{ return {{ top: 0, bottom: 427 }}; }},
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querySelectorAll(){{ return [row]; }}, querySelector(){{ return row; }}, style: {{}},
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}};
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function $(id){{ return id === 'messages' ? container : null; }}
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function _recentMessageScrollIntent(){{ return {intent_js}; }}
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function _recentMessageTouchScrollIntent(){{ return {intent_js}; }}
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function _isTouchLikeMessageViewport(){{ return {touch_js}; }}
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let _programmaticScroll = false; let _programmaticScrollSetAt = 0;
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const performance = {{ now(){{ return 1; }} }};
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function _suppressBrowserOverflowAnchor(){{ return null; }}
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function _deferClearProgrammaticScroll(){{}}
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function requestAnimationFrame(cb){{ cb(); }}
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function setTimeout(cb){{ cb(); return 1; }}
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const anchor = Object.assign({{ rawIdx: 53, sessionIdx: 53, key: 'k1', topOffset: {top_offset} }}, {anchor_extra});
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eval(extractFunc('_restoreMessageViewportAnchor'));
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const returned = _restoreMessageViewportAnchor(anchor, 0);
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console.log(JSON.stringify({{ returned, wrote: writes.length }}));
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"""
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def test_realign_refuses_stale_anchor_when_content_grew_no_intent():
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"""Content grew since capture (90000->90453) and no input intent, realign delta -453
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-> REFUSE (return false, no write). Mutation: delete the guard block and it writes."""
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m = json.loads(_run_node(_realign_harness(
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anchor_extra="{scrollHeightAtCapture: 90000}",
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cur_scroll_height=90453, rect_top=-453, top_offset=0, active_intent=False,
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)))
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assert m["returned"] is False and m["wrote"] == 0
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def test_realign_allows_fresh_anchor_no_growth():
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"""No growth since capture -> realign runs normally even with the same delta."""
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m = json.loads(_run_node(_realign_harness(
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anchor_extra="{scrollHeightAtCapture: 90453}",
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cur_scroll_height=90453, rect_top=-453, top_offset=0, active_intent=False,
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)))
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assert m["returned"] is True and m["wrote"] == 1
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def test_realign_allows_with_active_intent():
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"""Recent real input intent -> keep the legitimate realign even if content grew."""
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m = json.loads(_run_node(_realign_harness(
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anchor_extra="{scrollHeightAtCapture: 90000}",
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cur_scroll_height=90453, rect_top=-453, top_offset=0, active_intent=True,
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)))
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assert m["returned"] is True and m["wrote"] == 1
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def test_realign_backward_compatible_without_capture_geometry():
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"""Legacy anchor without scrollHeightAtCapture -> guard is a no-op, prior behavior."""
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m = json.loads(_run_node(_realign_harness(
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anchor_extra="{}",
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cur_scroll_height=90453, rect_top=-453, top_offset=0, active_intent=False,
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)))
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assert m["returned"] is True and m["wrote"] == 1
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def test_realign_allows_on_desktop_no_native_anchor():
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"""Desktop regression (#5637 gate cert): the exact stale-anchor case
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(content grew, no intent, delta -453) but on a hover+fine-pointer viewport where
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`.messages` is `overflow-anchor:none`. There is no native anchoring layer to hold
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the reader, so the guard MUST NOT refuse — the semantic scrollTop realign has to
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run or the desktop reader is left unheld after above-viewport growth.
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Mutation: drop the `_touchHold&&` term from the realign guard and this FAILS
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(the write is wrongly refused on desktop)."""
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m = json.loads(_run_node(_realign_harness(
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anchor_extra="{scrollHeightAtCapture: 90000}",
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cur_scroll_height=90453, rect_top=-453, top_offset=0, active_intent=False,
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touch_like=False,
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)))
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assert m["returned"] is True and m["wrote"] == 1
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# ---- fallback guard (_restoreMessageScrollSnapshotSameFrame) ---------------------
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def _fallback_harness(*, snapshot_scroll_height, cur_scroll_height, snapshot_top,
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active_intent: bool = False, touch_like: bool = True,
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init_scroll_top: int = 90030,
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snapshot_user_unpinned: bool = False,
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snapshot_pinned: bool = False,
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anchor=None, anchor_row_content_pos=None, container_top: int = 0,
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top_pad_now=None, input_generation: int = 0,
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delayed_input_generation=None, delayed_scroll_top: int = 89000,
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restore_fn: str = "_restoreMessageScrollSnapshotSameFrame") -> str:
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"""Node harness for the absolute-fallback path of _restoreMessageScrollSnapshotSameFrame.
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SCROLL-DEPENDENT geometry (round-3 gate-cert requirement): the anchor row's
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getBoundingClientRect().top is computed LIVE as `rowContentPos - scrollTop + container_top`
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— exactly how a real browser reports it — NOT a fixed constant. So after the fix
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writes `el.scrollTop += delta`, a subsequent rect read reflects the new position, and
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a certified hold number is physically realizable.
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anchor: dict for snapshot.anchor (with key/sessionIdx/topOffset[/topPadBefore]) or None.
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anchor_row_content_pos: the row's ABSOLUTE content position (document-space top). Its
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live viewport offset is rowContentPos - scrollTop. When None, the row lookup returns
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nothing (genuinely-gone anchor -> topPad-delta or raw).
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top_pad_now: current virtual top-spacer height (for the genuinely-gone topPad-delta path).
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"""
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js = UI_JS_PATH.read_text(encoding="utf-8")
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intent_js = "true" if active_intent else "false"
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touch_js = "true" if touch_like else "false"
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sh = "null" if snapshot_scroll_height is None else str(snapshot_scroll_height)
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anchor_js = "null" if anchor is None else json.dumps(anchor)
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row_present = anchor is not None and anchor_row_content_pos is not None
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row_pos_js = "0" if anchor_row_content_pos is None else str(anchor_row_content_pos)
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pad_now_js = "null" if top_pad_now is None else str(top_pad_now)
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return _extract_func_script(js) + f"""
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let writes = [];
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let stTop = {init_scroll_top};
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let _messageScrollInputGeneration = {input_generation};
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const CONTAINER_TOP = {container_top};
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const ROW_CONTENT_POS = {row_pos_js};
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const ROW_PRESENT = {"true" if row_present else "false"};
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const TOP_PAD_NOW = {pad_now_js};
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// A real browser's rect.top for a row is (rowContentPos - scrollTop) relative to the
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// document, so its offset below the container top is ROW_CONTENT_POS - scrollTop.
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const _anchorRow = ROW_PRESENT ? {{
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getBoundingClientRect(){{ return {{ top: CONTAINER_TOP + (ROW_CONTENT_POS - stTop) }}; }},
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getClientRects(){{ return [{{}}]; }},
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}} : null;
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const _topSpacer = (TOP_PAD_NOW === null) ? null : {{
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style: {{ height: TOP_PAD_NOW + 'px' }},
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}};
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const el = {{
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get scrollTop(){{ return stTop; }}, set scrollTop(v){{ writes.push(Math.round(v)); stTop = v; }},
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scrollHeight: {cur_scroll_height}, clientHeight: 427,
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getBoundingClientRect(){{ return {{ top: CONTAINER_TOP, bottom: CONTAINER_TOP + 427 }}; }},
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querySelector(sel){{
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if (sel === '[data-virtual-spacer="before"]') return _topSpacer;
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return _anchorRow;
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}},
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querySelectorAll(sel){{ return _anchorRow ? [_anchorRow] : []; }},
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|
}};
|
|
function $(id){{ return id === 'messages' ? el : null; }}
|
|
function _recentMessageScrollIntent(){{ return {intent_js}; }}
|
|
function _recentMessageTouchScrollIntent(){{ return {intent_js}; }}
|
|
function _isTouchLikeMessageViewport(){{ return {touch_js}; }}
|
|
// realign path fails (no anchor restore) so execution reaches the absolute fallback
|
|
function _restorePinnedMessageScrollSnapshot(snapshot){{
|
|
if(snapshot.pinned!==true) return false;
|
|
const pinnedTarget=el.scrollHeight-el.clientHeight-(Number(snapshot.bottom)||0);
|
|
el.scrollTop=pinnedTarget;
|
|
return true;
|
|
}}
|
|
function _restoreMessageViewportAnchor(){{ return false; }}
|
|
function _remountMessageViewportAnchor(){{ return false; }}
|
|
let _messageUserUnpinned = false; let _scrollPinned = true; let _nearBottomCount = 5;
|
|
let _lastScrollTop = 0; let _lastMessageClientHeight = 0;
|
|
let _programmaticScroll = false; let _programmaticScrollSetAt = 0;
|
|
const performance = {{ now(){{ return 1; }} }};
|
|
function _deferClearProgrammaticScroll(){{}}
|
|
function requestAnimationFrame(cb){{ cb(); }}
|
|
function setTimeout(cb){{ cb(); return 1; }}
|
|
const snapshot = {{ anchor: {anchor_js}, top: {snapshot_top}, bottom: 40,
|
|
scrollHeight: {sh}, inputGeneration: {input_generation}, pinned: {str(snapshot_pinned).lower()}, userUnpinned: {str(snapshot_user_unpinned).lower()} }};
|
|
eval(extractFunc('_desktopAnchorRealignDelta'));
|
|
eval(extractFunc('_messageScrollSnapshotInputChanged'));
|
|
eval(extractFunc('_abandonMessageScrollSnapshot'));
|
|
eval(extractFunc({json.dumps(restore_fn)}));
|
|
{restore_fn}(snapshot);
|
|
{f"stTop = {delayed_scroll_top}; _messageScrollInputGeneration = {delayed_input_generation}; {restore_fn}(snapshot);" if delayed_input_generation is not None else ""}
|
|
console.log(JSON.stringify({{ wrote: writes.length, writes,
|
|
messageUserUnpinned: _messageUserUnpinned, scrollPinned: _scrollPinned, finalScrollTop: Math.round(stTop) }}));
|
|
"""
|
|
|
|
|
|
def test_fallback_refuses_stale_snapshot_top_when_content_grew_no_intent():
|
|
"""Content grew since snapshot (90000->90453), reader not pinned, no intent, and the
|
|
absolute snapshot.top write would move scrollTop >8px -> REFUSE. This is the -578
|
|
on-device jump the userUnpinned check missed (re-pin flipped userUnpinned false).
|
|
Mutation: delete the fallback guard block and scrollHistory gets the stale write."""
|
|
m = json.loads(_run_node(_fallback_harness(
|
|
snapshot_scroll_height=90000, cur_scroll_height=90453, snapshot_top=89577,
|
|
active_intent=False,
|
|
)))
|
|
assert m["writes"] == []
|
|
assert m["messageUserUnpinned"] is True and m["scrollPinned"] is False
|
|
|
|
|
|
def test_fallback_allows_snapshot_top_when_no_growth():
|
|
"""No growth since snapshot -> the fallback keeps its authoritative absolute restore."""
|
|
m = json.loads(_run_node(_fallback_harness(
|
|
snapshot_scroll_height=90453, cur_scroll_height=90453, snapshot_top=89577,
|
|
active_intent=False,
|
|
)))
|
|
assert m["writes"] == [89577]
|
|
|
|
|
|
def test_fallback_backward_compatible_without_capture_scrollheight():
|
|
"""Legacy snapshot without scrollHeight -> guard no-op, prior absolute restore runs."""
|
|
m = json.loads(_run_node(_fallback_harness(
|
|
snapshot_scroll_height=None, cur_scroll_height=90453, snapshot_top=89577,
|
|
active_intent=False,
|
|
)))
|
|
assert m["writes"] == [89577]
|
|
|
|
|
|
def test_fallback_allows_snapshot_top_with_active_intent():
|
|
"""Content grew since snapshot, but the reader has recent real input intent -> the
|
|
fallback keeps its legitimate absolute restore (an actively-scrolling reader owns the
|
|
snapshot). Mirrors the realign-guard active-intent case.
|
|
Mutation: drop the `!_activeIntent` term from the fallback guard and this fails
|
|
(the write would be wrongly refused)."""
|
|
m = json.loads(_run_node(_fallback_harness(
|
|
snapshot_scroll_height=90000, cur_scroll_height=90453, snapshot_top=89577,
|
|
active_intent=True,
|
|
)))
|
|
assert m["writes"] == [89577]
|
|
|
|
|
|
def test_fallback_allows_snapshot_top_on_desktop_no_native_anchor():
|
|
"""Desktop regression (#5637 gate cert): the exact stale-snapshot case (content grew,
|
|
reader not pinned, no intent, absolute write would move >8px) but on a
|
|
hover+fine-pointer viewport where `.messages` is `overflow-anchor:none`. With no
|
|
native anchoring layer to hold the reader, the fallback MUST still WRITE rather than
|
|
refuse-and-latch userUnpinned. With NO anchor on the snapshot (and no top-spacer
|
|
geometry) there is nothing to realign against, so it keeps the raw snapshot.top —
|
|
the same authoritative absolute write as before.
|
|
Mutation: drop the `_fbTouchHold&&` term from the fallback guard and this FAILS
|
|
(the write is wrongly refused and userUnpinned is latched on desktop)."""
|
|
m = json.loads(_run_node(_fallback_harness(
|
|
snapshot_scroll_height=90000, cur_scroll_height=90453, snapshot_top=89577,
|
|
active_intent=False, touch_like=False,
|
|
)))
|
|
assert m["writes"] == [89577]
|
|
assert m["messageUserUnpinned"] is False and m["scrollPinned"] is True
|
|
|
|
|
|
def test_unpinned_anchor_miss_restores_on_desktop_without_native_anchor():
|
|
"""A desktop reader who deliberately scrolled up cannot be left to native
|
|
anchoring: desktop disables it. If the semantic row is temporarily absent,
|
|
the rebuild may clamp scrollTop toward zero before this function runs, so the
|
|
fallback must restore the snapshot rather than taking the mobile no-write exit.
|
|
"""
|
|
m = json.loads(_run_node(_fallback_harness(
|
|
snapshot_scroll_height=90000, cur_scroll_height=90453, snapshot_top=89577,
|
|
active_intent=False, touch_like=False, snapshot_user_unpinned=True,
|
|
init_scroll_top=0,
|
|
)))
|
|
assert m["writes"] == [89577]
|
|
assert m["messageUserUnpinned"] is True and m["scrollPinned"] is False
|
|
|
|
|
|
def test_delayed_restore_cannot_overwrite_new_desktop_input():
|
|
"""The synchronous restore owns generation 0, then the reader moves to 89000
|
|
before the delayed rAF restore. The second call must abandon the stale snapshot
|
|
instead of writing its old 89577 target."""
|
|
m = json.loads(_run_node(_fallback_harness(
|
|
snapshot_scroll_height=90453, cur_scroll_height=90453, snapshot_top=89577,
|
|
active_intent=False, touch_like=False, snapshot_user_unpinned=True,
|
|
init_scroll_top=89577, input_generation=0, delayed_input_generation=1,
|
|
)))
|
|
assert m["writes"] == [89577]
|
|
assert m["finalScrollTop"] == 89000
|
|
assert m["messageUserUnpinned"] is True and m["scrollPinned"] is False
|
|
|
|
|
|
@pytest.mark.parametrize("restore_fn", [
|
|
"_restoreMessageScrollSnapshot",
|
|
"_restoreMessageScrollSnapshotSameFrame",
|
|
])
|
|
def test_delayed_pinned_restore_cannot_overwrite_new_upward_input(restore_fn):
|
|
"""A pinned-at-capture snapshot must lose ownership before its tail write.
|
|
|
|
The reader moves upward before the delayed restore; the stale pinned snapshot
|
|
must not put them back at its captured tail-relative position.
|
|
"""
|
|
m = json.loads(_run_node(_fallback_harness(
|
|
snapshot_scroll_height=90453, cur_scroll_height=90453, snapshot_top=89577,
|
|
active_intent=False, touch_like=False, snapshot_pinned=True,
|
|
init_scroll_top=89577, input_generation=0, delayed_input_generation=1,
|
|
delayed_scroll_top=89000,
|
|
restore_fn=restore_fn,
|
|
)))
|
|
assert m["writes"] == [89986]
|
|
assert m["finalScrollTop"] == 89000
|
|
assert m["messageUserUnpinned"] is True and m["scrollPinned"] is False
|
|
|
|
|
|
@pytest.mark.parametrize("restore_fn", [
|
|
"_restoreMessageScrollSnapshot",
|
|
"_restoreMessageScrollSnapshotSameFrame",
|
|
])
|
|
def test_delayed_unpinned_restore_repins_reader_who_reached_bottom(restore_fn):
|
|
"""Abandoning a stale unpinned snapshot must reconcile a live bottom position."""
|
|
m = json.loads(_run_node(_fallback_harness(
|
|
snapshot_scroll_height=90453, cur_scroll_height=90453, snapshot_top=89577,
|
|
active_intent=False, touch_like=False, snapshot_user_unpinned=True,
|
|
init_scroll_top=89577, input_generation=0, delayed_input_generation=1,
|
|
delayed_scroll_top=90026,
|
|
restore_fn=restore_fn,
|
|
)))
|
|
assert m["writes"] == [89577]
|
|
assert m["finalScrollTop"] == 90026
|
|
assert m["messageUserUnpinned"] is False and m["scrollPinned"] is True
|
|
|
|
|
|
# ---- round-3 desktop anchor-realign (PR #5742): app's own scrollTop += delta idiom -----
|
|
# These use SCROLL-DEPENDENT rect mocks (rect.top = rowContentPos - scrollTop), so the
|
|
# certified hold numbers are physically realizable in a real browser — the round-2
|
|
# gate-cert requirement that fixed-rect mocks violated.
|
|
|
|
def test_realign_holds_reader_on_above_viewport_growth_desktop():
|
|
"""Reader parked up in history on desktop; above-viewport content grew since capture.
|
|
The anchor row was captured at topOffset 1000; the reader has ALREADY been carried
|
|
down by the browser to scrollTop 1480 (partial), and the row's content position is
|
|
2000 so its live offset is 2000-1480=520. The app idiom writes
|
|
scrollTop += (currentOffset - capturedOffset) = 1480 + (520 - 1000) = 1000, landing
|
|
the row back at its captured 1000px offset (2000 - 1000 = 1000). That HOLD is
|
|
physically realizable: after the write, rect.top = 2000 - 1000 = 1000 = capturedOffset.
|
|
Mutation: revert `_fbTarget` to the raw `target` (snapshot.top=1200) and this FAILS
|
|
(the reader is left at 1200, a 200px drift from the held content position)."""
|
|
m = json.loads(_run_node(_fallback_harness(
|
|
snapshot_scroll_height=90000, cur_scroll_height=90600, snapshot_top=1200,
|
|
active_intent=False, touch_like=False,
|
|
anchor={"key": "k1", "sessionIdx": 5, "topOffset": 1000},
|
|
anchor_row_content_pos=2000, container_top=0, init_scroll_top=1480,
|
|
)))
|
|
# scrollTop += (currentOffset - capturedOffset) = 1480 + ((2000-1480) - 1000) = 1000
|
|
assert m["writes"] == [1000]
|
|
# and the row is now held at its captured offset — physically consistent
|
|
assert m["finalScrollTop"] == 1000
|
|
assert m["messageUserUnpinned"] is False and m["scrollPinned"] is True
|
|
|
|
|
|
def test_realign_is_noop_when_already_aligned_desktop():
|
|
"""No arbiter: when the reader is already at the captured offset (row content pos 2000,
|
|
scrollTop 1000 -> live offset 1000 == captured 1000), the realign delta is 0 and no
|
|
move happens (delta < clamp is still written as the same value, i.e. a no-op write to
|
|
the same scrollTop). Proves the idiom does not perturb an already-correct position."""
|
|
m = json.loads(_run_node(_fallback_harness(
|
|
snapshot_scroll_height=90000, cur_scroll_height=90600, snapshot_top=1200,
|
|
active_intent=False, touch_like=False,
|
|
anchor={"key": "k1", "sessionIdx": 5, "topOffset": 1000},
|
|
anchor_row_content_pos=2000, container_top=0, init_scroll_top=1000,
|
|
)))
|
|
# currentOffset = 2000 - 1000 = 1000 == captured 1000 -> delta 0 -> scrollTop stays 1000
|
|
assert m["finalScrollTop"] == 1000
|
|
assert m["writes"] == [1000]
|
|
|
|
|
|
def test_realign_does_not_drift_on_below_viewport_tail_growth_desktop():
|
|
"""Below-viewport (tail) growth: the anchor row ABOVE the reader did NOT move
|
|
(content pos 2000, scrollTop 1000 -> offset 1000 == captured 1000), only content
|
|
below grew (scrollHeight 90000 -> 95000). The realign delta is 0 -> the reader is
|
|
NOT pulled downward. This is the conveyor-belt drift the round-2 arbiter formula
|
|
reintroduced; the app idiom cannot, because it keys on the ABOVE-viewport anchor row,
|
|
whose offset is unchanged by tail growth.
|
|
Mutation: a `snapshot.top + totalGrowth` formula would write 1000 + 5000 = 6000 and
|
|
drift the reader down 5000px; this asserts the held 1000."""
|
|
m = json.loads(_run_node(_fallback_harness(
|
|
snapshot_scroll_height=90000, cur_scroll_height=95000, snapshot_top=1000,
|
|
active_intent=False, touch_like=False,
|
|
anchor={"key": "k1", "sessionIdx": 5, "topOffset": 1000},
|
|
anchor_row_content_pos=2000, container_top=0, init_scroll_top=1000,
|
|
)))
|
|
assert m["finalScrollTop"] == 1000
|
|
assert m["writes"] == [1000]
|
|
|
|
|
|
def test_realign_genuinely_gone_anchor_uses_toppad_delta_desktop():
|
|
"""Anchor row genuinely gone (lookup returns null), but the snapshot carries
|
|
topPadBefore and the current virtual top-spacer is measurable. Mirror the topPad-delta
|
|
idiom: shift scrollTop by (padNow - padBefore) so the reader is held by the same
|
|
amount the content above moved. padBefore=800, padNow=1300 -> +500 from scrollTop 1000
|
|
-> 1500.
|
|
Mutation: drop the topPad-delta branch and it keeps raw snapshot.top (1200), a
|
|
300px drift from the topPad-held 1500."""
|
|
m = json.loads(_run_node(_fallback_harness(
|
|
snapshot_scroll_height=90000, cur_scroll_height=90500, snapshot_top=1200,
|
|
active_intent=False, touch_like=False,
|
|
anchor={"key": "gone", "sessionIdx": 999, "topOffset": 1000, "topPadBefore": 800},
|
|
anchor_row_content_pos=None, container_top=0, init_scroll_top=1000,
|
|
top_pad_now=1300,
|
|
)))
|
|
assert m["finalScrollTop"] == 1500
|
|
assert m["writes"] == [1500]
|
|
|
|
|
|
def test_realign_genuinely_gone_anchor_no_geometry_keeps_raw_desktop():
|
|
"""Anchor row gone AND no topPad geometry available -> keep the raw snapshot.top
|
|
(no guessing with an arbiter). snapshot.top=1200 -> writes 1200."""
|
|
m = json.loads(_run_node(_fallback_harness(
|
|
snapshot_scroll_height=90000, cur_scroll_height=90500, snapshot_top=1200,
|
|
active_intent=False, touch_like=False,
|
|
anchor={"key": "gone", "sessionIdx": 999, "topOffset": 1000},
|
|
anchor_row_content_pos=None, container_top=0, init_scroll_top=1000,
|
|
top_pad_now=None,
|
|
)))
|
|
assert m["writes"] == [1200]
|
|
|
|
|
|
def test_realign_gone_anchor_null_toppadbefore_does_not_fling_desktop():
|
|
"""greptile P1: anchor row gone, a virtual top-spacer IS present (padNow=1300), but the
|
|
snapshot carries NO captured topPadBefore (null). Number(null) is 0, so a naive
|
|
isFinite(padBefore) check would treat padBefore as 0 and add the ENTIRE 1300px spacer
|
|
to scrollTop (1000 -> 2300), flinging the reader far from their content. The guard
|
|
requires an ACTUAL captured topPadBefore, so with null it keeps the raw snapshot.top.
|
|
Mutation: drop the `_padBeforeRaw!=null` term and this FAILS (writes 2300, the fling)."""
|
|
m = json.loads(_run_node(_fallback_harness(
|
|
snapshot_scroll_height=90000, cur_scroll_height=90500, snapshot_top=1200,
|
|
active_intent=False, touch_like=False,
|
|
anchor={"key": "gone", "sessionIdx": 999, "topOffset": 1000, "topPadBefore": None},
|
|
anchor_row_content_pos=None, container_top=0, init_scroll_top=1000,
|
|
top_pad_now=1300,
|
|
)))
|
|
assert m["writes"] == [1200]
|
|
|
|
|
|
|
|
|
|
def _predicate_harness(*, pointer_coarse, computed_overflow_anchor, has_matchmedia=True,
|
|
inline_overflow_anchor="", ua="Mozilla/5.0 (Linux; Android 13)",
|
|
platform="Linux armv8l", max_touch_points=5) -> str:
|
|
"""Exercise the REAL _isTouchLikeMessageViewport + _browserOverflowAnchorActive
|
|
+ _isIOSWebKit against a fake element, mocking matchMedia, getComputedStyle and
|
|
navigator. `inline_overflow_anchor` simulates the inline `overflowAnchor:'none'`
|
|
that _restoreMessageViewportAnchor writes on #messages mid-realign — the value the
|
|
computed probe would transiently read. `ua`/`platform`/`max_touch_points` drive the
|
|
_isIOSWebKit branch (default: an Android touch device that is NOT iOS)."""
|
|
js = UI_JS_PATH.read_text(encoding="utf-8")
|
|
mm = "true" if pointer_coarse else "false"
|
|
has_mm = "true" if has_matchmedia else "false"
|
|
return _extract_func_script(js) + f"""
|
|
const HAS_MM = {has_mm};
|
|
if (HAS_MM) {{
|
|
globalThis.matchMedia = function(q){{ return {{ matches: (q === '(pointer:coarse)') ? {mm} : false }}; }};
|
|
}} else {{
|
|
globalThis.matchMedia = undefined;
|
|
}}
|
|
// Node 18+ ships a built-in read-only `navigator`; a plain assignment is silently
|
|
// ignored, so force the mock in with defineProperty.
|
|
Object.defineProperty(globalThis, 'navigator', {{ configurable: true, value: {{ userAgent: {json.dumps(ua)}, platform: {json.dumps(platform)}, maxTouchPoints: {max_touch_points} }} }});
|
|
// getComputedStyle reflects the INLINE override first (as a real browser would during
|
|
// a realign burst), else the resting computed value.
|
|
const el = {{ style: {{ overflowAnchor: {json.dumps(inline_overflow_anchor)} }} }};
|
|
globalThis.getComputedStyle = function(node){{
|
|
const inline = node && node.style && node.style.overflowAnchor;
|
|
return {{ overflowAnchor: inline || {json.dumps(computed_overflow_anchor)} }};
|
|
}};
|
|
eval(extractFunc('_browserOverflowAnchorActive'));
|
|
eval(extractFunc('_isIOSWebKit'));
|
|
eval(extractFunc('_isTouchLikeMessageViewport'));
|
|
console.log(JSON.stringify({{ touchLike: _isTouchLikeMessageViewport(el) }}));
|
|
"""
|
|
|
|
|
|
def test_predicate_stays_true_on_touch_when_inline_anchor_clobbered_to_none():
|
|
"""The claim that motivated choosing matchMedia over the computed probe: on a touch
|
|
device, when a prior realign tick has clobbered the inline `overflowAnchor` to 'none'
|
|
on #messages (its own scroll-write side effect, restored next frame), the predicate
|
|
MUST still report touch=true so the hold gate stays engaged across a realign burst.
|
|
matchMedia('(pointer:coarse)') reflects the input device and can't be mutated by that
|
|
inline write.
|
|
Mutation: revert _isTouchLikeMessageViewport to `return _browserOverflowAnchorActive(el)`
|
|
(the computed probe alone) and this FAILS — the probe reads the inline 'none' and
|
|
misclassifies the touch device as desktop."""
|
|
m = json.loads(_run_node(_predicate_harness(
|
|
pointer_coarse=True, computed_overflow_anchor="auto",
|
|
inline_overflow_anchor="none",
|
|
)))
|
|
assert m["touchLike"] is True
|
|
|
|
|
|
|
|
def test_predicate_false_on_desktop_fine_pointer():
|
|
"""Desktop (fine pointer): matchMedia('(pointer:coarse)') is false and the resting
|
|
computed overflow-anchor is 'none' -> predicate reports NOT touch, so the guards do
|
|
not fire and desktop keeps its scroll restore."""
|
|
m = json.loads(_run_node(_predicate_harness(
|
|
pointer_coarse=False, computed_overflow_anchor="none",
|
|
)))
|
|
assert m["touchLike"] is False
|
|
|
|
|
|
def test_predicate_falls_back_to_computed_probe_without_matchmedia():
|
|
"""Best-effort fallback: with no matchMedia available, the predicate uses the computed
|
|
overflow-anchor probe. A resting 'auto' (touch) -> true."""
|
|
m = json.loads(_run_node(_predicate_harness(
|
|
pointer_coarse=True, computed_overflow_anchor="auto", has_matchmedia=False,
|
|
)))
|
|
assert m["touchLike"] is True
|
|
|
|
|
|
# ---- iOS WebKit exclusion (_isIOSWebKit) — overflow-anchor is inert on iOS -------
|
|
|
|
def test_predicate_false_on_ios_iphone_despite_pointer_coarse():
|
|
"""iOS gate cert (#5637 round-2 RED): an iPhone is pointer:coarse with a resting
|
|
computed overflow-anchor of 'auto', so the round-1 predicate would classify it as a
|
|
hold-capable touch viewport and let the stale-anchor refusal fire. But overflow-anchor
|
|
is INERT on iOS WebKit, so refusing the restore leaves a scrolled-up reader unheld —
|
|
the same class as the desktop regression. The predicate MUST report NOT touch on iOS so
|
|
the semantic realign is kept.
|
|
Mutation: remove the `if(_isIOSWebKit()) return false;` line and this FAILS (iPhone is
|
|
misclassified as a hold-capable touch viewport)."""
|
|
m = json.loads(_run_node(_predicate_harness(
|
|
pointer_coarse=True, computed_overflow_anchor="auto",
|
|
ua="Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X) AppleWebKit/605.1.15 "
|
|
"(KHTML, like Gecko) Version/17.0 Mobile/15E148 Safari/604.1",
|
|
platform="iPhone", max_touch_points=5,
|
|
)))
|
|
assert m["touchLike"] is False
|
|
|
|
|
|
def test_predicate_false_on_ipados13_masquerading_as_mac():
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"""iPadOS 13+ reports a desktop UA + platform 'MacIntel' but has touch (maxTouchPoints>1),
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unlike a real Mac. overflow-anchor is inert there too, so it must be excluded from the
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refusal like the iPhone.
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Mutation: drop the `platform==='MacIntel' && maxTouchPoints>1` branch in _isIOSWebKit and
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this FAILS (iPad is treated as an anchor-capable touch device)."""
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m = json.loads(_run_node(_predicate_harness(
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pointer_coarse=True, computed_overflow_anchor="auto",
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ua="Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/605.1.15 "
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"(KHTML, like Gecko) Version/17.0 Safari/605.1.15",
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platform="MacIntel", max_touch_points=5,
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)))
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assert m["touchLike"] is False
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def test_predicate_true_on_android_not_ios():
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"""Android Chrome: pointer:coarse, overflow-anchor works, and it is NOT iOS — this is
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|
the one platform where the refusal is safe, so the predicate stays true. Guards against
|
|
an over-broad _isIOSWebKit that would also exclude Android.
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|
Mutation: broaden _isIOSWebKit to match any touch device (e.g. return maxTouchPoints>1)
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and this FAILS (Android would be wrongly excluded, re-opening the mobile jump)."""
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|
m = json.loads(_run_node(_predicate_harness(
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|
pointer_coarse=True, computed_overflow_anchor="auto",
|
|
ua="Mozilla/5.0 (Linux; Android 13; Pixel 7) AppleWebKit/537.36 (KHTML, like Gecko) "
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|
"Chrome/120.0.0.0 Mobile Safari/537.36",
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platform="Linux armv8l", max_touch_points=5,
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|
)))
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|
assert m["touchLike"] is True
|