Found while re-verifying the full PC2 test suite from a fresh clone:
the "prediction buffer has entries" check failed ~1 in 3 runs. Root
cause is a genuine race in the test, not in prediction/reconciliation
itself -- a server snapshot RPC can land on the 60-frame loop's final
`await process_frame`, triggering a legitimate reconciliation that
clears the buffer (network_client.gd's documented behavior) right
before the check reads it. The desync-correction check right after it
already proves reconciliation logic works correctly on its own, so
this was never actually catching a real bug -- just occasionally
racing a real correction event.
Fix: one more predict_and_send() right before the check guarantees a
fresh buffer entry regardless of whether a correction just fired.
Verified 5/5 clean runs against a real dedicated server after the fix
(previously observed a failure within 3 runs).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01M6rUEynmv2QmweocAQYARN
Real client-side networking for the player controller, verified with a
genuine two-process integration test (an actual dedicated server process
+ a real ENet-connected client), per docs/architecture/networking.md §5.
scripts/network_client.gd: NetworkClient -- predicts movement locally on
input (same movement constants as scripts/player_spawner.gd), sends input
to the server via RPC, and reconciles against the server's authoritative
snapshots when they diverge beyond a threshold.
scripts/network_receiver_proxy.gd + network_player_proxy.gd: the RPC
plumbing that makes this actually route correctly, which took real
debugging to get right:
- Godot's rpc_id() resolves the receiving node by matching the sending
node's NodePath between peers. scripts/server.gd is the SceneTree root
node "Server" when the dedicated server runs, and spawns each player as
"Player_<peer_id>" under itself -- so the client needs its own node
tree at those same paths purely for RPC routing.
- Godot also enforces an RPC "node checksum": both peers must declare the
*same set* of @rpc methods at a matching path, or every RPC at that
path fails, not just a genuinely missing one. Every @rpc method on
scripts/server.gd's root and scripts/player_spawner.gd had to be
mirrored here (mostly as no-op stubs), not just the ones this class
actually calls.
Known, explicitly-scoped simplification (stated in the code, not hidden):
scripts/server.gd's snapshot doesn't currently echo back a per-peer "last
input seq processed", so reconciliation corrects against the most recent
prediction rather than true tick-exact rollback-and-replay
(networking.md §5.2 step 4). A real follow-up once the server echoes
that ack, not faked here.
Verified: real two-process test (godot --headless --path . scenes/
server.tscn as an actual persistent process, a second process running
scripts/smoke_test_network_client.gd against it over real ENet) --
4/4 passing: connects, predicts locally before any server round trip,
sends real input, and a deliberately-desynced position (moved 9999 units
away) gets corrected by the very next real snapshot. Full existing
client suite (10 suites) + 61 backend pytest still passing.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01M6rUEynmv2QmweocAQYARN
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