Diagnostics

packages/diagnostics in the repository is a private Electron app for working against real devices. It is not published to npm. The project tests every change with it on an Apple TV and a HomePod. It also shows what a device sends.

What it does

• Pairs Apple TVs and stores the credentials.
• Connects several devices at once, through @corewire/devices.
• Has panels for remote control, now playing, volume, audio streaming, RAOP, multiroom, mDNS scans, encoding tools and stored credentials.
• Shows every message it sends or receives in a traffic view, decrypted and decoded. This is the traffic sink of reporter.
• Shows the log of each device, the events of its capabilities and statistics per device.
• Has a pairing proxy that sits between a controller and a device and records what passes.

Running it

From a checkout of the repository:

bun install
bun --cwd packages/diagnostics dev

bun --cwd packages/diagnostics pack builds installers for macOS, Linux and Windows into packages/diagnostics/release/.

The diag CLI

dev:agent starts the app with a small HTTP bridge on the loopback interface. The bridge offers every channel of the app to the diag command line tool:

bun --cwd packages/diagnostics dev:agent

bun run diag wait-ready
bun run diag devices --scan
bun run diag connect living-room
bun run diag mark
bun run diag call living-room device remote.press up
bun run diag traffic --since-mark --decoded
bun run diag events --since-mark
bun run diag logs --since-mark --group error

Command	Meaning
status	The bridge, its cursors and the devices
wait-ready	Waits for the app, after a restart too, and for its reconnects
devices [--scan]	The discovered devices
connect <device>, disconnect <device>	<device> is an id or a part of the name that matches one device
snapshot <device>	The current state of a device
call <device> <root> <path> [args...]	Calls an action or reads a value on the device
invoke <channel> [json]	Any channel of the app
mark	Remembers the current cursors, for --since-mark
logs, events, traffic	Reads a buffer, with filters such as --grep, --limit, --protocol and --direction
wait <logs|events|traffic>	Blocks until something matches
proxy status, proxy start, proxy stop	The pairing proxy

bun run diag --help lists every option. Actions that change something lasting, such as forgetting credentials or setting the volume above half, ask for --confirm.

A typical loop runs mark, does something and reads traffic, events and logs since the mark. When a request times out, the traffic shows whether the device answered at all.