Test Spec: J1939 Monitor Command¶

Document Control¶

Field	Value
Status	Implemented
Design doc	`docs/design/j1939-monitor-command.md`
Test file	`tests/test_cli.py`

Requirement Traceability¶

REQ ID	Description summary	TEST IDs
`REQ-J1939MON-01`	Command exists with the documented CLI surface	`TEST-J1939MON-01`, `TEST-J1939MON-02`, `TEST-J1939MON-03`, `TEST-J1939MON-04`
`REQ-J1939MON-02`	Monitor without an interface uses the sample/reference provider	`TEST-J1939MON-01`
`REQ-J1939MON-03`	Monitor with an interface uses the transport-backed path	`TEST-J1939MON-02`
`REQ-J1939MON-04`	`--pgn` filters the observation set and is echoed in the result	`TEST-J1939MON-03`, `TEST-J1939MON-04`
`REQ-J1939MON-05`	Structured output is observation-first rather than raw-frame-only	`TEST-J1939MON-01`, `TEST-J1939MON-02`, `TEST-J1939MON-03`
`REQ-J1939MON-06`	Standard output modes remain supported	`TEST-J1939MON-04`, `TEST-J1939MON-05`

Test Cases¶

TEST-J1939MON-01 — Monitor without interface uses sample provider¶

Given  no interface argument is provided
When   the operator runs `canarchy j1939 monitor --json`
Then   the system shall return a passive J1939 result envelope
And    the result shall report the sample/reference provider implementation
And    the first emitted event shall be a J1939 PGN observation

Fixture: built-in sample/reference provider.

TEST-J1939MON-02 — Monitor with interface uses transport-backed path¶

Given  the scaffold transport backend is configured
When   the operator runs `canarchy j1939 monitor can0 --json`
Then   the system shall return a passive J1939 result envelope
And    the result shall include `interface="can0"`
And    the result shall report the transport-backed implementation

Fixture: mocked transport config selecting the scaffold backend.

TEST-J1939MON-03 — PGN filter reduces the observation set¶

Given  the sample/reference provider emits more than one J1939 observation
When   the operator runs `canarchy j1939 monitor --pgn 65262 --json`
Then   the system shall echo `pgn_filter=65262` in the result
And    the returned observations shall only report PGN `65262`

Fixture: built-in sample/reference provider.

TEST-J1939MON-04 — Text output remains protocol-first¶

Given  a PGN filter is supplied
When   the operator runs `canarchy j1939 monitor --pgn 65262 --text`
Then   the system shall print the command header
And    the text output shall include the active PGN filter and protocol-first observation fields

Fixture: built-in sample/reference provider.

Fixtures And Environment¶

built-in sample/reference J1939 provider
mocked scaffold transport configuration for the live-path test

Explicit Non-Coverage¶

transport backend failure paths, which are covered by generic transport and CLI error handling
DBC enrichment, because j1939 monitor does not currently expose that surface