# live-conformance/ledger — the receipt ledger

The corpus of [`extensions/receipt-ledger.md`](../../extensions/receipt-ledger.md) §11, in one
file, `vectors.json`:

- `sources`: the sources the vectors bill from, by name, each a source document of §5.1;
- `vectors`: verification documents (§7.1), each a `tariff`, an `invoice`, the `previous`
  invoice or `null`, and the names of its `sources` in order, with the `outcome` §7.3 gives it;
- `keys`: the seller's, the buyers' and the two delivering parties' public keys.

**Ledger equivalence.** For each vector, a conforming verifier given its tariff, its invoice, its
previous invoice and its sources, resolved by name, reaches the outcome the vector states:

- `refuse`: the `reason` and where, `at`: `["tariff"]`, `["tariff", "seller"]` or `["tariff",
  "buyer"]`, `["invoice"]`, `["previous"]`, `["source", k]` for source `k`, or `["source", k, …]`
  followed by the place the source's own extension gives (live-metering §5.1, settlement §8.2,
  packaging §9, live-ads §9.2);
- `accept`: the invoice's `digest`, its `tariff`, `currency`, `start` and `end`, the number of
  `records`, each line (its source kind, source, unit, quantity, price, amount and the records it
  `cites`, each `[kind, identity]`), each energy row (scope, class, figures, joules and
  `max_ppm`), the `unmetered` figures and `coverage` of each scope, the `amount`, and the
  `reports` of §8: `ads`, one per ads source, and `delivery`, the parties and their overlaps.

The accepted vectors:

- `a_day`: one day's invoice over a lesson room, two delivering parties (one viewer acknowledges
  part of one object from both, in windows that overlap; one party serves a fetch free; the other
  declares delivery to viewers with no key), a viewer that forwarded sealed objects and states no
  tariff of its own, a package, ads under a policy that requires presentation claims and under one
  that does not;
- `the_next_invoice`: the next invoice of the chain, over a relay's session whose hop is
  unmetered (its room energy is partial) and a second package;
- `room_hops_of_three_classes`: a room whose hops are a model, a counter and an estimate, under a
  tariff of its own: one row each;
- `streams_stitched_by_others`: presentations of ads another party stitched, from three vectors
  of [`stitched/`](../stitched/) (`hls_stitched`; `form1_prefetch`, whose form-1 receipt states
  its own quartiles and spend beside the presented ones; and `squeezeback`, a shared break whose
  sessions' own claims are not all presented), under a tariff whose ad scope is the stitchers
  that corpus accepts; its report is stitched-presentation §7.5's statement, unchanged.

Every other vector is refused, a control of one defect: each reason of §10, the reused codes, and a
refusal of each source kind by its own extension.

**Provenance.** Generated here: `wai_receipt_ledger_vectors gen` writes `vectors.json` from fixed
seeds (the seller, the buyers, the two delivering parties, their viewers and objects) and from
sources taken unchanged from the corpora of the extensions the ledger reads: rooms and their
receipts from [`metering/`](../metering/) (`lesson`, `mixed_classes`, `receipt_bad_signature`,
`relay_recorded`), the forwarding viewer's statement and the room its hop records name from
[`settlement/`](../settlement/), ad rooms from [`ads/`](../ads/) (`live_break`, `gap`) and
[`presentation/`](../presentation/) (`video_rule`, `ceiling_exceeded_by_presented`), streams
stitched by others from [`stitched/`](../stitched/) (`hls_stitched`, `form1_prefetch`,
`squeezeback`, with the
manifests, responses and receipts they name, by their bytes), and the
packages `video-base-01` and `video-staged-01` of
[`pack-conformance/packs/`](../../pack-conformance/packs/). When one of those corpora is
regenerated, so is this one. Nothing here was fetched from outside the repository.

Regenerate and check:

    cd wai/wai-rs
    cargo run -q --no-default-features --features receipt_ledger --bin wai_receipt_ledger_vectors -- gen ../live-conformance/ledger
    cargo run -q --no-default-features --features receipt_ledger --bin wai_receipt_ledger_vectors -- verify ../live-conformance/ledger
    cargo test -q --no-default-features --features receipt_ledger --test receipt_ledger
    python3 -I ../live-conformance/receipt_ledger_verify.py ../live-conformance/ledger

The second implementation, `receipt_ledger_verify.py`, shares no code with `wai-rs`. It verifies
each source with the second implementation of that source's own corpus, recomputes every line,
citation, row and report, requires every mutated copy of the corpus to fail, and requires the corpus
to catch it with each of its own checks dropped.