No test ever exercised the client ChunkDataDecoder against real byte data
before this (M2 chunk streaming was never fed real content on PC2/PC3).
Added scripts/smoke_test_chunk_codec_interop.gd, decoding the backend's
exact golden fixtures (backend/tests/fixtures/chunks/*.bin) and asserting
byte-identical logical values -- the real cross-language contract this
whole persistence system depends on. It found three bugs on first run:
1. chunk_data_decoder.gd's _read_float32/_write_float32 used `bits as
float`/`val as int`, a numeric cast in GDScript, not an IEEE-754
bitcast -- silently corrupted every non-integer position/rotation/
scale/bounds value (1.5 decoded as 1069547520.0, verified). Fixed with
PackedByteArray.decode_float/encode_float (real bitcast, same
little-endian order as the rest of this format).
2. backend/app/services/chunk_codec.py's binary codec wrote bounds as
min+size, disagreeing with world.md §3's documented min+max wire
format and with the client's actual (correct) decoder -- corrupted
every chunk's bounds on the wire despite the backend's own JSON path
using min+max correctly. Fixed the binary encode/decode to match the
spec; regenerated the golden fixtures.
3. chunk_data_decoder.gd's object-properties parsing used
`JSON.parse_string(props_str) or {}` -- GDScript's `or` is a boolean
operator, not Python/JS-style short-circuit-return, so this silently
evaluated to a bool for any object with real property data, crashing
on assignment to the typed `properties: Dictionary` field. Fixed with
an explicit type check.
Full backend suite (132/132) and 4 sibling client smoke tests re-verified
clean after all three fixes; no other `or {}`/`or []` instances of bug 3's
pattern found elsewhere in the codebase.
Implements docs/architecture/world_persistence_impl.md §9's backend task:
chunk/room/revision Postgres schema (migration 0005), a Python port of the
world.md §3.6 binary chunk codec with golden-file tests, a WorldStore
service (world.md §5.1 minus flush_dirty/rebuild_index), the public
world-content router (rooms/chunks CRUD, optimistic concurrency, batch
writes) and the internal read-only API for dedicated servers, and
game_servers.py changes: a per-spawn bearer token, --api-url/--server-token
args, and a real "ready"-field wait replacing _await_port, which bound the
UDP port before content existed and failed open (no error) past its
deadline.
create_world now auto-creates the "main" room.
Deviations/findings, not silently decided:
- chunk_codec.py implements real IEEE-754 float32 packing rather than
mirroring a confirmed bug in scripts/chunk_data_decoder.gd's
_read_float32/_write_float32, which do a lossy int<->float cast instead
of a bit reinterpretation (verified against Godot 4.6.2 headless) and
will corrupt any non-integer position/rotation/scale/bounds value. Not
fixed here (client-side, out of scope); flagged for the client task.
- world_persistence_impl.md references a world's monotonic
content_revision (§6/§7.2/§8.1) but never defines where it's stored.
Resolved as MAX(id) over the append-only world_chunk_revisions table,
scoped to world_id, rather than adding an undocumented column.
- No existing Godot-side golden fixture/test vectors were found to reuse,
so tests/fixtures/chunks/*.bin are authored fresh from this
implementation (see generate_fixtures.py).
Verification: 132/132 backend pytest tests pass against a real ephemeral
Postgres (both reusing an already-running instance and cold via
conftest.py's own docker-compose bootstrap), including migration
upgrade/downgrade/upgrade, codec round-trip + validation-error tests, and
full HTTP round trips for PUT/GET/batch/delete/revisions/rollback and the
internal API's token auth.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y2FESCaMXeJpC9gSctiEeD
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