Result of a LetItCrash.Async.observe_async/1,2 block.

A Report records the async work that happened inside an observer block: which Tasks/processes were spawned, which completed, which crashed, which exceptions were caught by telemetry, plus timing data. The struct is the API — its fields are public and stable.

Three named assertions consume a Report:

• LetItCrash.Async.assert_no_silent_swallow/1,2
• LetItCrash.Async.assert_all_completed/2

(Idempotency uses a function-form assertion that does not consume a Report; see LetItCrash.Async.assert_idempotent/2.)

Fields

• :spawned — list of {pid, kind, started_at} for processes observed during the block. kind is :task | :unknown. started_at is in monotonic milliseconds.
• :completed — list of {pid, result, finished_at} for spawned work that returned a value.
• :crashed — list of {pid, reason, finished_at} for spawned work that exited abnormally.
• :exceptions — list of telemetry exception events seen during the block. Each entry is {event_name, measurements, metadata}.
• :warnings — list of atom hints from the observer (e.g. :no_oban_events_seen). Reserved; usually empty in v0.5.0.
• :duration_ms — wall-clock duration of the block in milliseconds.
• :started_at — monotonic time (ms) when the block started.
• :ended_at — monotonic time (ms) when the block ended.

Reports are pure data: no behavior beyond @type t/0.