Test Spec: Config Show Command¶

Document Control¶

Field	Value
Status	Implemented
Design doc	`docs/design/config-show-command.md`
Test file	`tests/test_cli.py`, `tests/test_mcp.py`

Requirement Traceability¶

REQ ID	Description summary	TEST IDs
`REQ-CONFIG-01`	Command exists with the documented CLI surface	`TEST-CONFIG-01`, `TEST-CONFIG-04`
`REQ-CONFIG-02`	Effective transport values are reported	`TEST-CONFIG-01`, `TEST-CONFIG-05`, `TEST-CONFIG-06`, `TEST-CONFIG-07`, `TEST-CONFIG-09`
`REQ-CONFIG-03`	Per-field source reporting is present	`TEST-CONFIG-01`, `TEST-CONFIG-02`, `TEST-CONFIG-03`, `TEST-CONFIG-05`, `TEST-CONFIG-06`, `TEST-CONFIG-07`, `TEST-CONFIG-09`
`REQ-CONFIG-04`	Environment variables override file config	`TEST-CONFIG-03`
`REQ-CONFIG-05`	File config overrides defaults when env vars are absent	`TEST-CONFIG-02`, `TEST-CONFIG-05`, `TEST-CONFIG-06`, `TEST-CONFIG-07`
`REQ-CONFIG-06`	Defaults are reported when no overrides exist	`TEST-CONFIG-01`
`REQ-CONFIG-07`	Config-file path and existence are reported	`TEST-CONFIG-01`, `TEST-CONFIG-04`
`REQ-CONFIG-08`	Standard output modes remain supported	`TEST-CONFIG-04`, `TEST-CONFIG-08`
`REQ-CONFIG-09`	Configured default CAN interface is used when CLI interface is omitted	`TEST-CONFIG-10`
`REQ-CONFIG-10`	CLI interface takes precedence over configured default CAN interface	`TEST-CONFIG-11`
`REQ-CONFIG-11`	Missing interface returns actionable error when no fallback exists	`TEST-CONFIG-12`

Test Cases¶

TEST-CONFIG-01 — Defaults are reported with default provenance¶

Given  no relevant config-file entries or environment variables are present
When   the operator runs `canarchy config show --json`
Then   the system shall return the effective default transport configuration
And    each reported source shall be marked as `default`

Fixture: mocked empty config file state and cleared environment.

TEST-CONFIG-02 — File config overrides defaults¶

Given  the config file defines transport backend and interface values
When   the operator runs `canarchy config show --json`
Then   the system shall return those file-backed values
And    the affected source entries shall be marked as `file`

Fixture: mocked config file values with no environment overrides.

TEST-CONFIG-03 — Environment variables override file config¶

Given  both the config file and environment define overlapping transport settings
When   the operator runs `canarchy config show --json`
Then   the system shall prefer the environment values
And    the overridden source entries shall be marked as `env`

Fixture: mocked file config plus environment-variable overrides.

TEST-CONFIG-04 — Config-file discovery state is explicit¶

Given  the default config-file path does not exist
When   the operator runs `canarchy config show --json`
Then   the system shall include the resolved config-file path
And    the result shall report `config_file_found=false`

Fixture: mocked home directory path and missing config file.

TEST-CONFIG-05 — Capture controls can come from the config file¶

Given  the config file defines capture-limit and capture-timeout values
When   the operator runs `canarchy config show --json`
Then   the system shall report those effective values
And    both source entries shall be marked as `file`

Fixture: mocked config file values.

TEST-CONFIG-06 — Active-ack safety can come from the config file¶

Given  the config file enables active-command acknowledgement
When   the operator runs `canarchy config show --json`
Then   the system shall report `require_active_ack=true`
And    the source entry shall be marked as `file`

Fixture: mocked config file values.

TEST-CONFIG-07 — Default J1939 DBC can come from the config file¶

Given  the config file defines `CANARCHY_J1939_DBC`
When   the operator runs `canarchy config show --json`
Then   the system shall report the configured J1939 DBC path
And    the source entry shall be marked as `file`

Fixture: mocked config file values.

TEST-CONFIG-08 — Text output includes source annotations¶

Given  the configuration snapshot is available
When   the operator runs `canarchy config show --text`
Then   the system shall render a human-readable configuration summary
And    the output shall include source annotations and config-file status text

Fixture: mocked empty config file state and cleared environment.

TEST-CONFIG-09 — Default CAN interface appears in config show¶

Given  the config file defines `[transport].default_interface`
When   the operator runs `canarchy config show --json`
Then   the system shall report that value as `default_interface`
And    the source entry shall be marked as `file`

Fixture: mocked config file values.

TEST-CONFIG-10 — Interface-taking commands use configured default¶

Given  the config file defines `[transport].default_interface = "vcan7"`
When   the operator runs an interface-taking command without a command-line interface
Then   the system shall use `vcan7` as the command interface

Fixture: mocked scaffold backend with default interface config.

TEST-CONFIG-11 — Command-line interface overrides configured default¶

Given  the config file defines `[transport].default_interface = "vcan7"`
When   the operator runs an interface-taking command with `can0` on the command line
Then   the system shall use `can0` as the command interface

Fixture: mocked scaffold backend with default interface config.

TEST-CONFIG-12 — Missing interface without default fails clearly¶

Given  no command-line interface is provided
And    no default CAN interface is configured
When   the operator runs an interface-taking command that requires an interface
Then   the system shall fail with `INTERFACE_REQUIRED`
And    the error hint shall tell the operator to pass an interface or configure `[transport].default_interface`

Fixture: mocked scaffold backend with no default interface config.

Fixtures And Environment¶

mocked config-file dictionaries returned by _load_user_config
patched environment-variable state
patched home-directory lookup for the missing-config-file case
scaffold transport responses for interface fallback command coverage

Explicit Non-Coverage¶

malformed config-file parsing failures, which are covered by generic configuration loading behavior
future non-transport config domains that are not yet surfaced by config show