Generate ASTM messages

The @cosyte/synth/astm subpath builds ASTM laboratory messages through @cosyte/astm's own emit surface - buildAstmMessage for the E1394 record layer and composeAstmFrames for the E1381 frame layer - so every message is spec-clean by construction and round-trips through the parser with zero warnings. @cosyte/astm is an optional peer dependency, needed only for this subpath.

The surface covers both layers:

• Records (E1394) - generateAstmResult emits a full H/P/O/R…/C/L result report; generateAstmOrder emits the H/P/O/L order side. Both are built through buildAstmMessage, so the H|\^& delimiter declaration, the record type letters, the per-type sequence counters, and the L terminator are the parser's own conservative emit - never a hand-written byte.
• Framing (E1381) - generateAstmResultFramed wraps the same records in the <STX> FN text <ETB|ETX> CS <CR><LF> frame envelope, with the modulo-256 checksum and the 0–7 frame number computed by @cosyte/astm, never faked.

Every value at the P (patient) record - the name, birthdate, and the practice- and laboratory-assigned patient IDs - is drawn from the synthetic-safety providers, so no output can be real or plausibly-real PHI. The practice- and lab-assigned IDs are minted independently, so they stay distinct (exactly as @cosyte/astm keeps them distinct on parse). synth is a format/conformance generator, not a clinical simulator: a generated result pairs a code and a value with no claim of clinical coherence.

A result report, spec-clean by construction

The round-trip harness proves spec-cleanliness by @cosyte/astm's own judgment - a spec-clean message re-parses with zero warnings and re-serializes byte-identically:

import { generateAstmResult, astmRoundTrip } from "@cosyte/synth/astm";

// Same seed → byte-identical ASTM record stream, on any machine, any run.
const result = astmRoundTrip(generateAstmResult({ seed: 12345 }));
result.warnings; // => []
result.byteStable; // => true
result.specClean; // => true

A framed (E1381) message

The framed twin carries the same records with a real frame envelope - the checksum and frame numbers are computed, so it decodes with zero frame and record warnings:

import { generateAstmResultFramed, astmFramedRoundTrip } from "@cosyte/synth/astm";

const framed = astmFramedRoundTrip(generateAstmResultFramed({ seed: 12345 }));
framed.warnings; // => []
framed.specClean; // => true

A reproducible corpus

astmCorpus builds a deep-frozen, seed-tagged set - a downstream repo pins the seed and gets a stable fixture set that regenerates identically:

import { astmCorpus } from "@cosyte/synth/astm";

const corpus = astmCorpus({ seed: 42 });
corpus.artifacts.length; // => 2
corpus.artifacts.every((a) => a.warnings.length === 0); // => true

Vendor-quirk mode

Quirk mode ships for ASTM - a non-standard &Z& escape round-trips to exactly ASTM_UNKNOWN_ESCAPE_SEQUENCE, re-badged by @cosyte/astm's public referenceCorpus profile, and a site-defined record type round-trips to ASTM_RECORD_UNKNOWN_TYPE. See Vendor-quirk generation. The frame-layer transport quirks (a deliberately-wrong checksum, framing dropped over TCP) target non-profile diagnostics and are not generated.