MobDev.Bench.Preflight (mob_dev v0.5.5)

Pre-run checklist for the iOS battery bench.

Walks through the things that have to be right before locking the screen and running for 30 minutes. Each check returns :ok | {:error, message}.

Goals:

Catch the misconfigurations that would invalidate a run before the run starts (saves ~30 min of wasted bench time).
Tell the user exactly what's wrong and how to fix it.
Be testable — each check is a pure function returning a tagged result.

Checks performed

USB / hardware UDID — at least one of: USB-connected device reachable via idevice_id -l, or a configured :hw_udid.
App installed — bundle id appears in xcrun devicectl device info apps.
BEAM reachable — Node.connect succeeds.
RPC responsive — rpc.call(node, :erlang, :node, []) returns within 2 seconds. Distinguishes "BEAM up but suspended" from "fully alive".
NIF version — mob_nif:battery_level/0 is exported. (Indicates the installed app build is recent enough.)
Background NIF — mob_nif:background_keep_alive/0 is exported. Required for screen-off bench mode.

Each check is independent — failure in (3) doesn't skip (5); we run them all and report a complete picture.

check_result()

Result for a single check.

all_ok?(results)

Returns true if every result is {:ok, _}. Stricter overall check than examining individual results — useful for deciding whether to abort.

pretty(results)

Format the results as a multi-line string with ✓/✗ markers.

run(opts)

Run all preflight checks and return a list of {name, result} tuples in the order they were run.

@type check_result() :: {:ok, String.t()} | {:error, String.t()}

Result for a single check.

@spec all_ok?([{atom(), check_result()}]) :: boolean()

Returns true if every result is {:ok, _}. Stricter overall check than examining individual results — useful for deciding whether to abort.

@spec pretty([{atom(), check_result()}]) :: String.t()

Format the results as a multi-line string with ✓/✗ markers.

@spec run(keyword()) :: [{atom(), check_result()}]

Run all preflight checks and return a list of {name, result} tuples in the order they were run.

Common options:

:platform — :ios (default) or :android — selects platform-specific hardware and app_installed checks
:node — node atom (required for BEAM checks)
:cookie — cookie atom
:bundle_id — app bundle id
:host — IP/host for EPMD (default: derive from node)
:require_keep_alive — boolean, default true (set false for screen-on bench)

iOS-specific:

Android-specific: