`helpers/mock_websocket.md` does not declare `active_connection`, which the suite uses 193 times across 28 files — plus eight tests calling five members that do not exist

[owenpearson]

Summary

uts/realtime/unit/helpers/mock_websocket.md is the contract the realtime unit specs are written against, and the specs use a great deal that it does not declare. Most of it is one omission repeated 193 times, which is cheap to fix. The rest is eight tests calling five members that do not exist at all.

This costs an SDK that already has a working harness nothing — we implemented the missing pieces by inference and lost no tests. It costs the next SDK, deriving from the contract alone, eight unimplementable tests and a lot of guessing.

Line references are against d9a04ca; paths are relative to uts/realtime/unit/.

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What the contract declares

interface MockWebSocket (helpers/mock_websocket.md:27-49) exposes events, send_to_client, send_to_client_and_close, simulate_disconnect(error?), send_ping_frame, await_next_message_from_client, await_connection_attempt, await_client_close and reset.

interface PendingConnection (:70) exposes url, protocol, timestamp and five respond_with_* methods, including respond_with_success(connected_message: ProtocolMessage) (:76), respond_with_dns_error() (:79) and respond_with_error(error_message: ProtocolMessage, then_close: bool = true) (:80).

enum MockEventType (:51-59) and struct MockEvent (:61-64, fields type, timestamp, data) are the event model.

1. Four names the suite depends on that the contract never declares

Name	Usage	Status
mock_ws.active_connection	193 times across 28 of the 56 spec files	Not in interface MockWebSocket. Appears in mock_websocket.md only inside two usage examples, :181 and :411
MockEvent.connection and MockEvent.message	connection/connection_failures_test.md:171, connection/connection_recovery_test.md:623; .message at connection_recovery_test.md:445, :631, :635	MockEvent has type, timestamp and data only. The intended spelling is presumably .data
MockWebSocketClient	26 times in 3 files — channels/channel_annotations.md (15), channels/channel_update_delete_message.md (9), channels/channel_history.md (2)	Defined nowhere; every other file uses MockWebSocket. None of these three files calls install_mock either
create_realtime_client(...)	connection/connection_open_failures_test.md:208, connection/connection_failures_test.md:313, channels/channel_detach.md:434	Defined nowhere; every other file writes Realtime(options: …)

active_connection is the significant one. It is the single most-used mock member in the suite and it is not part of the interface. channels/channel_detach.md:429 goes further and assigns to it:

mock_ws = MockWebSocket(
  onConnectionAttempt: (conn) =>
    mock_ws.active_connection = conn      # :429
    conn.respond_with_connected()         # :430 — see below
)

so an implementer cannot even tell whether it is meant to be a read-only accessor the mock maintains or a field the test populates. (We made it read-only, maintained by the mock. It works, but it is a guess.)

2. Five calls on members that do not exist, or that do something else

Test	Written	The contract offers
realtime/unit/RTL5l/detach-attached-when-disconnected-1 (channels/channel_detach.md:418)	conn.respond_with_connected() at :430	respond_with_success(connected_message: ProtocolMessage) (:76). respond_with_connected is the only occurrence in the whole uts/ tree, and it is called with no argument, so no CONNECTED would reach the client even if the method existed
realtime/unit/RTN13d/ping-deferred-disconnected-1 (connection/connection_ping_test.md:556)	mock_ws.active_connection.close_from_server() at :607	simulate_disconnect() (:34). close_from_server appears nowhere else in uts/
realtime/unit/RTN16f/recover-initializes-msgserial-0 and realtime/unit/RTN16j/recover-channel-serials-0 (connection/connection_recovery_test.md)	mock_ws.events.filter(e => e.type == "ws_frame" AND e.direction == "client_to_server") at :444 and :629-630	MESSAGE_FROM_CLIENT. Neither a ws_frame event type nor a direction field exists — three undefined names across two tests
realtime/unit/RTN17f/fallback-on-error-0 (connection/fallback_hosts_test.md:121)	conn.respond_with_error("Host unresolvable") at :138, under the comment # Primary domain: unresolvable (simulated) at :137	respond_with_error takes a ProtocolMessage, not a string, and it establishes the connection before having the server send an ERROR. The condition the comment describes is respond_with_dns_error() (:79)
realtime/unit/RTN17i/prefer-primary-domain-0 (connection/fallback_hosts_test.md:17)	mock_ws.active_connection.close() at :74	Neither declared nor equivalent to anything that is. simulate_disconnect() is presumably meant

Separately, the contract's own example at mock_websocket.md:275 calls conn.respond_with_success() with no argument, against a signature that requires one — worth making the connected_message parameter optional, since a good number of tests only need the connection established.

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Proposed fix

Two halves, and the first is much the cheaper:

1. Declare what the suite already uses. Add active_connection: PendingConnection? to interface MockWebSocket and say whether the mock maintains it or the test sets it; give MockEvent the connection and message accessors the tests read (or repoint those five call sites onto .data); and make respond_with_success's argument optional. This alone makes the great majority of the suite derivable from the contract.
2. Repoint the eight tests in section 2 onto methods that exist, and replace MockWebSocketClient and create_realtime_client with the spellings the other 53 files use.

Found while deriving uts/realtime/unit for ably-python (all 54 specs, 481 tests).