"""Regression tests for #4856: Android scroll-to-top on every interaction.""" from pathlib import Path REPO = Path(__file__).parent.parent UI_JS = (REPO / "static" / "ui.js").read_text(encoding="utf-8") MESSAGES_JS = (REPO / "static" / "messages.js").read_text(encoding="utf-8") _FUNC_MARKER = "window._fixMobileScrollJank=function _fixMobileScrollJank(){" _RAF_MARKER = "requestAnimationFrame(()=>{" def _extract_fix_mobile_scroll_jank(src: str) -> str: idx = src.find(_FUNC_MARKER) assert idx != -1, "_fixMobileScrollJank not found in ui.js" depth = 0 for i, ch in enumerate(src[idx:], idx): if ch == "{": depth += 1 elif ch == "}": depth -= 1 if depth == 0: return src[idx : i + 1] raise AssertionError("Could not extract _fixMobileScrollJank") def _extract_raf_body(fn_src: str) -> str: idx = fn_src.find(_RAF_MARKER) assert idx != -1, "requestAnimationFrame callback not found in function" depth = 0 for i, ch in enumerate(fn_src[idx:], idx): if ch == "{": depth += 1 elif ch == "}": depth -= 1 if depth == 0: return fn_src[idx : i + 1] raise AssertionError("Could not extract rAF body") def test_fix_sets_none_not_auto(): # Base-fails/head-passes: function must set 'none' to suppress Chromium # scroll-anchor re-selection; 'auto' is already the CSS default so setting # it is a no-op and leaves the anchor engine active during the DOM wipe. fn = _extract_fix_mobile_scroll_jank(UI_JS) assert "overflowAnchor='none'" in fn, ( "_fixMobileScrollJank() must set overflowAnchor='none' to suppress " "Chromium scroll-anchor re-selection during the DOM wipe (#4856)." ) assert "overflowAnchor='auto'" not in fn, ( "_fixMobileScrollJank() must not set overflowAnchor='auto'; that is " "already the CSS resting value on mobile and is a no-op." ) def test_raf_cleanup_checks_none(): # The rAF guard must check for 'none' so it only clears the inline style # it set; checking 'auto' was always false and left the inline style on. fn = _extract_fix_mobile_scroll_jank(UI_JS) raf = _extract_raf_body(fn) assert "overflowAnchor==='none'" in raf, ( "The rAF cleanup in _fixMobileScrollJank() must check for 'none' so it " "clears the inline style after the synchronous scrollTop write lands." ) assert "overflowAnchor==='auto'" not in raf, ( "The rAF cleanup must not check for 'auto'; that check was always false." ) def test_rebuild_path_calls_fix_before_wipe(): # renderMessages() must call _fixMobileScrollJank() before innerHTML='' so # anchor suppression is active during the full wipe-and-rebuild window. fix_idx = UI_JS.find("window._fixMobileScrollJank()") assert fix_idx != -1, ( "renderMessages() must call window._fixMobileScrollJank() before innerHTML=''." ) wipe_idx = UI_JS.find("innerHTML=''", fix_idx) assert wipe_idx != -1, ( "innerHTML='' not found after _fixMobileScrollJank() call site." ) assert fix_idx < wipe_idx, ( "_fixMobileScrollJank() must be called before innerHTML='' in renderMessages()." ) def test_rebuild_path_marks_dom_wipe_scroll_as_programmatic(): # During innerHTML='' the scroller can transiently collapse to clientHeight # and clamp scrollTop to 0. That browser event must be suppressed as # programmatic; otherwise the scroll listener treats it as user upward # intent and disables live auto-follow. fix_idx = UI_JS.find("window._fixMobileScrollJank()") assert fix_idx != -1, "renderMessages() guard call not found" wipe_idx = UI_JS.find("innerHTML=''", fix_idx) assert wipe_idx != -1, "innerHTML='' not found after _fixMobileScrollJank()" window = UI_JS[fix_idx:wipe_idx] assert "_programmaticScroll=true" in window, ( "renderMessages() must mark the DOM wipe/rebuild scroll event as " "programmatic before innerHTML='' can clamp scrollTop." ) assert "_programmaticScrollSetAt=performance.now()" in window assert UI_JS.find("_deferClearProgrammaticScroll(160)", wipe_idx) != -1, ( "renderMessages() must clear the programmatic-scroll suppression after " "the rebuild/post-render paint window." ) def test_recent_render_scroll_artifact_window_suppresses_upward_unpin(): # Some browsers emit a follow-up scroll event shortly after renderMessages() # finishes (for example while late layout settles after a send). With no # wheel/touch intent, that post-render upward delta is still a render # artifact and must not disable live follow. assert "let _lastMessageRenderAt=-Infinity" in UI_JS assert "_lastMessageRenderAt=performance.now()" in UI_JS assert "function _recentMessageRenderArtifactWindow" in UI_JS listener_idx = UI_JS.find("el.addEventListener('scroll'") assert listener_idx != -1, "messages scroll listener not found" listener = UI_JS[listener_idx: listener_idx + 4000] assert "_recentMessageRenderArtifactWindow(1400)" in listener assert "!_recentMessageTouchScrollIntent()" in listener assert "!_recentNonMessageScrollIntent()" in listener assert "!_recentMessageWheelIntent()" in listener, ( "#4970: the post-render artifact suppression must also require no recent " "low-delta message-pane wheel intent so a gentle trackpad scroll-up is " "not swallowed." ) assert listener.find("return;") < listener.find("if(movedUp){"), ( "recent render artifact scrolls must return before the movedUp branch " "can mark the reader unpinned." ) # ── #4970 low-delta wheel intent: behavioral node-harness ──────────────────── import json # noqa: E402 import shutil # noqa: E402 import subprocess # noqa: E402 import pytest # noqa: E402 NODE = shutil.which("node") def _balanced_block(src: str, brace_start: int) -> str: depth = 0 for i in range(brace_start, len(src)): ch = src[i] if ch == "{": depth += 1 elif ch == "}": depth -= 1 if depth == 0: return src[brace_start + 1 : i] raise AssertionError("balanced block not found") def _scroll_listener_raf_body() -> str: listener_start = UI_JS.index("el.addEventListener('scroll'") raf_start = UI_JS.index("requestAnimationFrame(()=>", listener_start) brace_start = UI_JS.index("{", raf_start) return _balanced_block(UI_JS, brace_start) def _run_listener_with_wheel_intent( samples, *, render_artifact, wheel_intent, scrollbar_drag=False, key_scroll=False ): """Run the extracted scroll-listener body in node with controllable stubs. Mirrors the #4295 harness shape but injects the #4970 helpers so we can exercise the production suppression path: artifact window active AND a recent gentle wheel intent must still unpin (return _messageUserUnpinned). """ payload = { "body": _scroll_listener_raf_body(), "samples": samples, "renderArtifact": bool(render_artifact), "wheelIntent": bool(wheel_intent), "scrollbarDrag": bool(scrollbar_drag), "keyScroll": bool(key_scroll), } script = ( "const payload = " + json.dumps(payload) + ";\n" + r""" const step = new Function( 'el', '_lastScrollTop', '_lastMessageClientHeight', '_nearBottomCount', '_scrollPinned', '_messageUserUnpinned', '_newMessageCueVisible', '_programmaticScroll', '_cancelBottomSettle', '_clearNewMessageScrollCue', '_syncScrollToBottomCue', '_updateSessionStartJumpButton', '_isSessionEndlessScrollEnabled', '_messagesTruncated', '_loadOlderMessages', '_recentMessageRenderArtifactWindow', '_recentMessageTouchScrollIntent', '_recentNonMessageScrollIntent', '_recentMessageWheelIntent', '_scrollbarDragActive', '_recentMessageKeyScrollIntent', // The extracted listener body uses bare `return;` in the suppression branch. // Wrap it in an inner arrow IIFE so that early return exits the IIFE (not the // outer Function), then read the mutated locals afterward. Without this the // suppression path would return undefined before the state snapshot. '(()=>{' + payload.body + `})(); return { _lastScrollTop, _lastMessageClientHeight, _nearBottomCount, _scrollPinned, _messageUserUnpinned, }; ` ); let state = { _lastScrollTop: 800, _lastMessageClientHeight: null, _nearBottomCount: 0, _scrollPinned: true, _messageUserUnpinned: false, }; const noop = () => {}; const renderArtifact = () => payload.renderArtifact; const noTouch = () => false; const noNonMessage = () => false; const wheelIntent = () => payload.wheelIntent; const keyScroll = () => payload.keyScroll; for (const sample of payload.samples) { state = step( sample, state._lastScrollTop, state._lastMessageClientHeight, state._nearBottomCount, state._scrollPinned, state._messageUserUnpinned, false, false, noop, noop, noop, noop, () => false, false, noop, renderArtifact, noTouch, noNonMessage, wheelIntent, payload.scrollbarDrag, keyScroll ); } console.log(JSON.stringify(state)); """ ) result = subprocess.run( [NODE, "-e", script], check=True, capture_output=True, text=True, timeout=30, ) return json.loads(result.stdout.strip()) @pytest.mark.skipif(NODE is None, reason="node not on PATH") class TestPostRenderWheelIntentScope: # A small upward scrollTop delta (800 -> 760) is `movedUp`. We hold the # render artifact window OPEN for all cases so the only variable is whether # the reader had recent gentle wheel intent. _SAMPLES = [{"scrollTop": 760, "scrollHeight": 1200, "clientHeight": 200}] def test_gentle_wheel_inside_artifact_window_still_unpins(self): # #4970 MUST-FIX: with the artifact window active but a recent low-delta # wheel intent, a real upward scroll must NOT be swallowed — it must # unpin live-follow just like any genuine scroll-up. state = _run_listener_with_wheel_intent( self._SAMPLES, render_artifact=True, wheel_intent=True ) assert state["_messageUserUnpinned"] is True, ( "A genuine gentle (low-delta) wheel scroll-up inside the post-render " "artifact window must still unpin; the suppression must be scoped to " "the no-intent artifact case only." ) assert state["_scrollPinned"] is False def test_no_intent_artifact_inside_window_is_suppressed(self): # Control: same upward delta, same open window, but NO wheel intent — a # true post-render artifact — stays pinned (the suppression still works). state = _run_listener_with_wheel_intent( self._SAMPLES, render_artifact=True, wheel_intent=False ) assert state["_messageUserUnpinned"] is False, ( "A no-intent upward delta inside the artifact window is a render " "artifact and must be suppressed (reader stays pinned)." ) assert state["_scrollPinned"] is True def test_gentle_wheel_outside_window_unpins(self): # Outside the artifact window the suppression never applies, so the # upward delta unpins regardless of intent tracking. state = _run_listener_with_wheel_intent( self._SAMPLES, render_artifact=False, wheel_intent=False ) assert state["_messageUserUnpinned"] is True assert state["_scrollPinned"] is False def test_scrollbar_drag_inside_window_still_unpins(self): # #4970 review SHOULD-FIX: a manual scrollbar-drag upward scroll inside # the post-render window is real user intent and must NOT be swallowed, # even with no wheel/touch intent recorded. state = _run_listener_with_wheel_intent( self._SAMPLES, render_artifact=True, wheel_intent=False, scrollbar_drag=True, ) assert state["_messageUserUnpinned"] is True, ( "A scrollbar-drag upward scroll inside the artifact window must " "unpin; the suppression must not swallow an active scrollbar drag." ) assert state["_scrollPinned"] is False def test_keyboard_scroll_inside_window_still_unpins(self): # #4970 review (greptile P1): a keyboard scroll-up (PageUp/Arrow/etc.) # inside the post-render window is real intent and must NOT be swallowed, # even with no wheel/touch/scrollbar intent recorded. state = _run_listener_with_wheel_intent( self._SAMPLES, render_artifact=True, wheel_intent=False, key_scroll=True, ) assert state["_messageUserUnpinned"] is True, ( "A keyboard scroll-up inside the artifact window must unpin; the " "suppression must not swallow a recent keyboard scroll intent." ) assert state["_scrollPinned"] is False def test_low_delta_wheel_intent_is_tracked_separately(): # The intent recorder must stamp _lastMessageWheelIntentMs for ANY upward # wheel (deltaY<0), not only the decisive deltaY<-30 sticky-unpin threshold. assert "let _lastMessageWheelIntentMs=-Infinity" in UI_JS assert "function _recentMessageWheelIntent" in UI_JS rec_idx = UI_JS.find("function _recordNonMessageScrollIntent") assert rec_idx != -1, "_recordNonMessageScrollIntent not found" rec = UI_JS[rec_idx: rec_idx + 1400] assert "e.deltaY<0) _lastMessageWheelIntentMs=performance.now()" in rec, ( "#4970: _recordNonMessageScrollIntent must record low-delta upward wheel " "intent (deltaY<0) separately from the decisive deltaY<-30 unpin." ) # The decisive sticky-unpin threshold must remain unchanged. assert "e.deltaY< -30" in rec, ( "The existing deltaY<-30 direct sticky-unpin threshold must be preserved." ) def _extract_fn_body(name: str) -> str: idx = UI_JS.find("function " + name + "(") assert idx != -1, name + " not found in ui.js" brace = UI_JS.index("{", idx) depth = 0 for i in range(brace, len(UI_JS)): ch = UI_JS[i] if ch == "{": depth += 1 elif ch == "}": depth -= 1 if depth == 0: return UI_JS[idx : i + 1] raise AssertionError("unbalanced body for " + name) def test_session_switch_reset_clears_wheel_intent(): # #4970 review MUST-FIX 1: _resetScrollDirectionTracker() must clear the # low-delta wheel intent stamp so a gentle wheel in the previous chat does # not leak into the new chat's first post-render artifact window. body = _extract_fn_body("_resetScrollDirectionTracker") assert "_lastMessageWheelIntentMs=-Infinity" in body, ( "_resetScrollDirectionTracker() must reset _lastMessageWheelIntentMs so " "stale wheel intent cannot cross a session switch." ) def test_stream_start_reset_clears_wheel_intent(): # #4970 review MUST-FIX 2: _resetStreamScrollFollow() must clear the wheel # intent stamp so a gentle wheel just before a fresh stream cannot # under-suppress a no-intent artifact and silently disable live follow. body = _extract_fn_body("_resetStreamScrollFollow") assert "_lastMessageWheelIntentMs=-Infinity" in body, ( "_resetStreamScrollFollow() must reset _lastMessageWheelIntentMs so " "stale wheel intent cannot cross a fresh stream start." ) def test_suppression_gates_on_scrollbar_drag(): # #4970 review SHOULD-FIX 3: the post-render suppression must not fire while # a scrollbar drag is active — that upward scroll is real user intent. assert "let _scrollbarDragActive=false" in UI_JS listener_idx = UI_JS.find("el.addEventListener('scroll'") assert listener_idx != -1, "messages scroll listener not found" listener = UI_JS[listener_idx: listener_idx + 4000] assert "!_scrollbarDragActive" in listener, ( "#4970 review: the suppression branch must reference !_scrollbarDragActive " "so a scrollbar-drag upward scroll inside the window is not swallowed." ) def test_keyboard_scroll_intent_tracked_and_gated(): # #4970 review (greptile P1): keyboard message-pane scrolling must be recorded # as user intent and excluded from the post-render suppression branch. assert "let _lastMessageKeyScrollIntentMs=-Infinity" in UI_JS assert "function _recentMessageKeyScrollIntent" in UI_JS # A keydown listener must stamp the intent for the pane scroll keys. assert "_lastMessageKeyScrollIntentMs=now;" in UI_JS, ( "a keydown handler must stamp _lastMessageKeyScrollIntentMs when the " "reader uses the keyboard to scroll the message pane." ) assert "if(bottomDistance>120) _lastMessageScrollIntentMs=now;" in UI_JS, ( "keyboard-driven manual-reader snapshot intent must be guarded by " "distance from the live tail." ) assert "'PageUp'" in UI_JS and "'PageDown'" in UI_JS # The suppression branch must consult it. listener_idx = UI_JS.find("el.addEventListener('scroll'") listener = UI_JS[listener_idx: listener_idx + 4000] assert "!_recentMessageKeyScrollIntent()" in listener, ( "#4970 review: the suppression branch must reference " "!_recentMessageKeyScrollIntent() so a keyboard scroll-up unpins." ) # Both resets must clear the keyboard stamp (stale-state hygiene). assert "_lastMessageKeyScrollIntentMs=-Infinity" in _extract_fn_body( "_resetScrollDirectionTracker" ) assert "_lastMessageKeyScrollIntentMs=-Infinity" in _extract_fn_body( "_resetStreamScrollFollow" ) assert "_isMessageInteractiveKeyTarget" in UI_JS assert "button,a[href],select,summary" in UI_JS @pytest.mark.skipif(NODE is None, reason="node not on PATH") def test_space_on_transcript_button_does_not_stamp_key_scroll_intent(): # Maintainer MUST-FIX: Space on a focused transcript control activates the # control; it is NOT a scroll. Because the handler is capture-phase, it must # inspect the target/active element directly rather than rely on defaultPrevented. start = UI_JS.index("const _MESSAGE_SCROLL_KEYS=new Set") end = UI_JS.index(" let _scrollRaf=0;", start) region = UI_JS[start:end] script = ( "const region = " + json.dumps(region) + ";\n" + r""" let _lastMessageKeyScrollIntentMs = -Infinity; const performance = { now: () => 1234 }; const el = { contains(node){ return !!(node && node.inMessages); }, matches(sel){ return sel === ':hover'; }, }; const document = { activeElement: null, _handler: null, addEventListener(type, fn){ if(type === 'keydown') this._handler = fn; }, }; function makeNode({tag='DIV', inMessages=true, interactive=false, editable=false}={}){ return { tagName: tag, inMessages, isContentEditable: editable, closest(sel){ return interactive ? this : null; }, }; } // Run via a closure so the stamped variable lives with the extracted handler. const env = Function('el','document','performance', `let _lastMessageKeyScrollIntentMs=-Infinity; ${region}\nreturn {handler:document._handler, get:()=>_lastMessageKeyScrollIntentMs, setActive:(n)=>{document.activeElement=n;}};`)(el, document, performance); const button = makeNode({tag:'BUTTON', interactive:true}); env.setActive(button); env.handler({key:' ', target:button}); const afterSpace = env.get(); const pane = makeNode({tag:'DIV', interactive:false}); env.setActive(pane); env.handler({key:'PageUp', target:pane}); const afterPageUp = env.get(); console.log(JSON.stringify({afterSpace, afterPageUp})); """ ) result = subprocess.run( [NODE, "-e", script], check=True, capture_output=True, text=True, timeout=30 ) state = json.loads(result.stdout.strip()) assert state["afterSpace"] is None, ( "JSON serializes -Infinity as null; Space on a focused transcript button " "must leave the stamp at -Infinity/null." ) assert state["afterPageUp"] == 1234 def test_streaming_tick_calls_fix_before_dom_writes(): # The streaming render tick in messages.js must call _fixMobileScrollJank() # before _lastRenderMs=performance.now() so anchor suppression covers every # incremental DOM update during streaming. guard_idx = MESSAGES_JS.find("window._fixMobileScrollJank") assert guard_idx != -1, ( "The streaming tick must call window._fixMobileScrollJank() before DOM writes." ) render_idx = MESSAGES_JS.find("_lastRenderMs=performance.now()") assert render_idx != -1, "streaming render timestamp not found in messages.js" assert guard_idx < render_idx, ( "The mobile scroll-jank guard must run before streaming DOM work begins." )