Decision records

TL;DR One row per architecture decision, with a one-line summary and the issues it relates to. The Issues column resolves the #40 to #45 coordinates that appear in source comments but link nowhere else in the repo.

Each file states one decision and keeps its number for life; it is never renumbered, and a reversed decision changes its Status to Superseded by 00NN rather than moving. See ../CONTRIBUTING-docs.md for how these are written.

#	Decision	Status	Issues
0000	Fill only what real socket.io observably does; never invent	Accepted	#64
0001	The public class is Server, not MockServer	Accepted	#64
0002	new Server(url) is activation; there is no start()	Accepted	#64
0003	The Server url argument is required	Accepted	#64
0004	Connection completes one tick later so connect handlers register in time	Accepted	#40, #65
0005	A missing server fires connect_error at once, no retry, plus console.error	Accepted	#65
0006	The handshake carries only fields a mock has a source for	Accepted	#65
0007	noUncheckedIndexedAccess guards the delivery-layer map lookups	Accepted	#66
0008	The adapter registration API lands before v1.0.0	Accepted	#66
0009	smocket does not mock raw WebSocket; that is MSW's lane	Accepted	#66
0010	One defer primitive keeps per-socket delivery FIFO	Accepted	#40, #41, #67
0011	Socket ids match socket.io's shape, not its source	Accepted	#67
0012	Timed client callbacks settle on disconnect; retained callbacks stay connection-owned	Accepted	#45, #67, #359, #360
0013	Reconnecting yields a fresh socket and id, with no old rooms	Accepted	#45, #67
0014	io.on('connection') fires the server side before the client connect	Accepted	#88, #350
0015	A review bot reads a diff against intent; CI keeps the mechanical checks	Accepted	#101
0016	volatile is accepted and drops only in the pre-connect window	Accepted	#110
0017	off follows the underlying emitter: Node on the server, component-emitter on the client	Accepted	#103
0018	Per-socket delivery delay is an adapter scheduling hook, keyed by sid, preserving FIFO	Accepted	#78
0019	A version number promises fidelity, not the current result	Accepted	#115
0020	close() tears down sockets and unregisters only the current server	Accepted	#193, #359
0021	Event maps and socket data survive the server substitution seam	Accepted	#171
0022	Root Socket names the server type; smocket-client owns the client type	Accepted	#178, #235
0023	smocket-client re-exports one shared client lookup without owning connection state	Accepted	#235
0024	Assemble an independent consumer from the canonical chat application	Superseded by 0039	#208, #451
0025	Built-in Adapter observation stays on the live rooms map	Accepted	#238
0026	Non-binary payloads cross the default parser's JSON snapshot boundary	Accepted	#237, #250
0027	One workflow drives three isolated application case-study targets	Superseded by 0039	#218, #451
0028	disconnect(true) closes the shared client Manager group	Accepted	#236, #254
0029	Parent broadcast conformance stops before narrowing	Accepted	#269
0030	The public direct connection API rejects observers when its server closes	Accepted	#277, #350
0031	Adapters register before admission and may observe whole-socket removal	Accepted	#278
0032	Trace final broadcast routing without retaining payloads	Accepted	#262
0033	Socket state follows lifecycle while volatile delivery uses private client readiness	Accepted	#275
0034	Packet middleware preserves entry order and completes independently	Accepted	#268
0035	Inherited emitter behavior follows each receiver	Accepted	#274
0036	Drop final broadcast recipients by sid	Accepted	#263
0037	Keep local broadcast management canonical	Accepted	#265
0038	SharedWorker uses explicit host and client subpaths with a narrow facade	Accepted	#376, #377, #379
0039	Retire chat-room evaluation paths after maintained replacements exist	Accepted	#451