# telemetry-conformance — delivery telemetry

The corpus of [`extensions/delivery-telemetry.md`](../extensions/delivery-telemetry.md)
§9: observations, their CMCD version 2 reports and CMSD fields, and session logs with
their metrics. Every value here is a string or an integer, the same on every machine.

- `observations/` — one observation (§2) each, every event kind among them: requests
  with the object's members, a response, the play states, the first presentation and a
  later one (which CMCD does not report), stalls with their metrics, a switch, a layer
  change, a dropped frame, dispatch outcomes, an abandon, an end with its claim pointer,
  a low-latency live session, and strings RFC 9651 escapes (a quote and a backslash in
  a capability in a custom key, a quote in a URL in an Event-mode report).
- `expected/cmcd.json` — for each observation: its mode (`request`, `event` or `none`),
  its report (§3, §4), and for Request mode its header shards (§4.2).
- `invalid/` — observations every reader refuses (§2.4): a member unknown or missing,
  the wrong version, a session id that is not hexadecimal, an Event-mode observation
  with no time, an integer past 2⁵³ − 1, a time past an RFC 9651 Integer, a claim
  before the end, an unknown event, a response key on a request and a request key on a
  response, a switch to its own path or for an unknown reason, a pin refusal with no
  reason, an unknown object type, a content id past 64 characters or holding an address
  or a URL, an object URL with a query, a fragment, user information (behind `//`, behind
  backslashes, behind no slash, or behind a mixed separator), a backslash, or a `@` in
  its path (§8.2), a presentation at no layer,
  an unknown cohort.
  `expected/refused.json` lists them.
- `cmsd/` — CMSD-Static descriptions of a base and of a derived layer, and a
  CMSD-Dynamic field from two nodes (§6); `expected/cmsd.json`, their fields.
- `cmsd-read/cases.json` — CMSD fields to read (§6.6): fields as §6.1 to §6.3 write them,
  the same with their keys in another order, with `v=1` and with a key or parameter of
  another sender, and fields refused with each code of §6.6 (not a Dictionary or List, a
  duration or throughput as a String, a layer not in decimal or with a leading zero, a short
  hash, an operation as a String, a server as a Token, a drop count not in decimal, version
  2); `expected/cmsd-read.json`, each one's description or refusal.
- `logs/` — session logs (§7.1), one observation per line: a session with stalls, one
  open at its end; an exit before start; a start failure. `expected/qoe.json`, their
  metrics (§7.2).
- `cml/` — the differential (§9.3).

**Verifiers.**

- `wai_telemetry verify .` (from `../wai-rs`, feature `telemetry`): reads every input
  from disk, requires each observation to write back as given, recomputes every
  expected file and requires it byte for byte, reads every report back, and requires
  every `invalid/` observation refused. `wai_telemetry gen .` writes the corpus.
- `cmsd_read_verify.py` (`python3 -I cmsd_read_verify.py .`): the second implementation of
  §6.6, written from that text and RFC 9651 and sharing no code with `wai-rs`: it parses
  every field of `cmsd-read/` with its own RFC 9651 reader and requires each outcome, reads
  every field of `expected/cmsd.json` back to its description, requires §6.6's table to be
  the codes the corpus gives, and requires every mutated copy of the corpus to fail.
- `cml/differential.mjs` (`npm ci && node differential.mjs ..` in `cml/`): builds each
  report from the extension's tables in JavaScript, not from `wai-rs`'s output; encodes
  it with an independent open-source CMCD and CMSD library at the versions
  `package-lock.json` locks, in the mode the event fixes, with the header shards for
  Request mode; requires the bytes of `expected/cmcd.json` and `expected/cmsd.json`;
  reads the expected strings back with the library's dictionary, query and header
  readers and requires the members; and validates every report, and the Event-mode
  reports together, requiring no error.

**Provenance.** Generated here: session ids, content hashes and timestamps are fixed
values chosen for the corpus. No recorded traffic.