David/HERMES-GIELIE
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

stage: merge #6390 (scroll preservation after live-to-final settlement)

Browse source
This commit is contained in:
nesquena-hermes 2026-07-22 20:43:04 +00:00
commit 6e2267dd5f
3 changed files with 117 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

9
static/messages.js
View file

@ -5955,10 +5955,17 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
// render also populates the cache with the correctly-collapsed DOM, and
// the same-frame JS restore absorbs the collapse so there is no jump.
// (#5260 gate-cert: keep-open must be transient + uncached for everyone.)
// #6385: capture the scroll snapshot from the LIVE DOM before arming
// keep-open, so the collapse render below anchors to the content the
// reader was actually viewing — not to a stale intermediate state where
// the worklog was temporarily expanded.
const _doneLiveScrollSnapshot=typeof _captureMessageScrollSnapshot==='function'
? _captureMessageScrollSnapshot()
: null;
if(typeof _armKeepSettledWorklogOpen==='function') _armKeepSettledWorklogOpen(_settledStreamId);
syncTopbar();renderMessages({preserveScroll:true});
if(typeof _disarmKeepSettledWorklogOpen==='function') _disarmKeepSettledWorklogOpen();
if(typeof _renderMessagesWithScrollSnapshot==='function') _renderMessagesWithScrollSnapshot();
if(typeof _renderMessagesWithScrollSnapshot==='function') _renderMessagesWithScrollSnapshot({_prescrollSnapshot:_doneLiveScrollSnapshot});
else renderMessages({preserveScroll:true});
if(shouldFollowOnDone&&typeof scrollToBottom==='function') scrollToBottom();
if(typeof noteWorkspaceMutationsFromToolCalls==='function') noteWorkspaceMutationsFromToolCalls(S.toolCalls);

8
static/ui.js
View file

@ -15307,7 +15307,13 @@ function _restoreMessageScrollSnapshotSameFrame(snapshot){
}
}
function _renderMessagesWithScrollSnapshot(options){
const scrollSnapshot=_captureMessageScrollSnapshot();
// Accept an optional pre-captured scroll snapshot via _prescrollSnapshot.
// When provided, it is used INSTEAD of capturing a fresh one from the current
// DOM state — essential for the STREAM_DONE collapse render: the caller has
// already captured the snapshot from the LIVE DOM (before keep-open was armed),
// and re-capturing from the intermediate expanded-worklog state would capture
// stale anchors that no longer exist after the worklog collapses. (#6385)
const scrollSnapshot=(options&&options._prescrollSnapshot)||_captureMessageScrollSnapshot();
renderMessages({...(options||{}),preserveScroll:true});
_restoreMessageScrollSnapshotSameFrame(scrollSnapshot);
}

107
tests/test_issue4970_stream_done_shrink_regression.py
View file

@ -171,18 +171,32 @@ def test_stream_done_runs_scroll_preserving_collapse_pass_after_disarm():
# UNCONDITIONALLY right after disarm (covers both pin states), THEN scrollToBottom()
# only for followers to re-settle at the tail. This makes keep-open genuinely
# one-frame for everyone.
#
# Round 10 (#6385): capture the scroll snapshot from the LIVE DOM before arming
# keep-open, so the collapse render below anchors to the content the reader was
# actually viewing — not to a stale intermediate state where the worklog was
# temporarily expanded. The pre-capture variable must be defined before arm and
# threaded into the collapse pass as `_prescrollSnapshot`.
pre_capture_idx = MESSAGES_JS.index("_doneLiveScrollSnapshot")
arm_idx = MESSAGES_JS.index("_armKeepSettledWorklogOpen")
assert pre_capture_idx < arm_idx, (
"_doneLiveScrollSnapshot must be captured before _armKeepSettledWorklogOpen "
"to snapshot the live (not expanded-worklog) DOM positions."
)
disarm_idx = MESSAGES_JS.index("_disarmKeepSettledWorklogOpen()")
after = MESSAGES_JS[disarm_idx : disarm_idx + 700]
# The collapse pass must run after disarm for BOTH pin states.
assert "_renderMessagesWithScrollSnapshot()" in after, (
# The collapse pass must run after disarm for BOTH pin states, and it must
# carry the pre-captured live snapshot.
assert "_renderMessagesWithScrollSnapshot({_prescrollSnapshot:_doneLiveScrollSnapshot})" in after, (
"after _disarmKeepSettledWorklogOpen() the STREAM_DONE handler must run a "
"scroll-preserving collapse pass (_renderMessagesWithScrollSnapshot) so the "
"forced-open worklog collapses back to the user/live state without the jump."
"scroll-preserving collapse pass (_renderMessagesWithScrollSnapshot) with the "
"pre-captured live snapshot so the forced-open worklog collapses back to "
"the user/live state without the jump."
)
# The follower re-settle (scrollToBottom) must come AFTER the collapse render —
# otherwise a pinned follower keeps the forced-open DOM (scrollToBottom does not
# re-render). This is the exact pinned-path bug the second RED gate-cert caught.
collapse_pos = after.index("_renderMessagesWithScrollSnapshot()")
collapse_pos = after.index("_renderMessagesWithScrollSnapshot")
follow_pos = after.index("shouldFollowOnDone")
assert collapse_pos < follow_pos, (
"the collapse render must run BEFORE the shouldFollowOnDone scrollToBottom() "
@ -200,3 +214,86 @@ def test_stream_done_runs_scroll_preserving_collapse_pass_after_disarm():
assert "_captureMessageScrollSnapshot()" in wrapper
assert "_restoreMessageScrollSnapshotSameFrame" in wrapper
@pytest.mark.skipif(shutil.which("node") is None, reason="node required for behavioral test")
def test_prescroll_snapshot_bypasses_capture_no_option_fallback_still_captures():
"""Sentinel _prescrollSnapshot reaches restore without re-capture.
Behavioral harness for _renderMessagesWithScrollSnapshot:
1. Supply a sentinel snapshot via _prescrollSnapshot, stub
_captureMessageScrollSnapshot with a counter — proves the
sentinel reaches _restoreMessageScrollSnapshotSameFrame
without a second capture.
2. Call with no options — proves the no-option fallback still
calls _captureMessageScrollSnapshot() normally (the contract
for callers at static/ui.js:9565, 14416, 14424).
3. Call with empty options {} — same fallback proof.
"""
wrapper = _extract("_renderMessagesWithScrollSnapshot")
harness = textwrap.dedent(f"""
let captureCount = 0;
let restoredSnapshot = null;
let renderedOptions = null;
globalThis._captureMessageScrollSnapshot = () => {{
captureCount++;
return {{_sentinel: 'fresh-capture', bottom: 0, pinned: true}};
}};
globalThis.renderMessages = (opts) => {{ renderedOptions = opts; }};
globalThis._restoreMessageScrollSnapshotSameFrame = (snap) => {{ restoredSnapshot = snap; }};
{wrapper}
// Test 1: supplied _prescrollSnapshot -> use it, do NOT capture
const sentinel = {{_sentinel: 'pre-captured', bottom: 42, pinned: true}};
_renderMessagesWithScrollSnapshot({{_prescrollSnapshot: sentinel}});
const test1_usedPrescroll = restoredSnapshot === sentinel;
const test1_noCapture = captureCount === 0;
const test1_preservedArgs = renderedOptions && renderedOptions._prescrollSnapshot === sentinel;
// Reset
captureCount = 0; restoredSnapshot = null; renderedOptions = null;
// Test 2: no options -> fall back to _captureMessageScrollSnapshot()
_renderMessagesWithScrollSnapshot();
const test2_captured = captureCount === 1;
const test2_usedCapture = restoredSnapshot && restoredSnapshot._sentinel === 'fresh-capture';
// Reset
captureCount = 0; restoredSnapshot = null; renderedOptions = null;
// Test 3: empty options object -> still fall back to capture
_renderMessagesWithScrollSnapshot({{}});
const test3_captured = captureCount === 1;
const test3_usedCapture = restoredSnapshot && restoredSnapshot._sentinel === 'fresh-capture';
console.log(JSON.stringify({{
test1_usedPrescroll,
test1_noCapture,
test1_preservedArgs,
test2_captured,
test2_usedCapture,
test3_captured,
test3_usedCapture
}}));
""")
res = subprocess.run(["node", "-e", harness], capture_output=True, text=True, timeout=30)
assert res.returncode == 0, res.stderr
out = json.loads(res.stdout.strip())
assert out["test1_usedPrescroll"] is True, (
"supplied _prescrollSnapshot must reach _restoreMessageScrollSnapshotSameFrame"
)
assert out["test1_noCapture"] is True, (
"supplied _prescrollSnapshot must bypass _captureMessageScrollSnapshot()"
)
assert out["test1_preservedArgs"] is True, (
"options passed to _renderMessagesWithScrollSnapshot must be forwarded to renderMessages"
)
assert out["test2_captured"] is True, (
"no-option call must fall back to _captureMessageScrollSnapshot()"
)
assert out["test2_usedCapture"] is True, (
"no-option call's captured snapshot must reach _restoreMessageScrollSnapshotSameFrame"
)
assert out["test3_captured"] is True, (
"empty-options call must fall back to _captureMessageScrollSnapshot()"
)
assert out["test3_usedCapture"] is True, (
"empty-options call's captured snapshot must reach _restoreMessageScrollSnapshotSameFrame"
)