open-standards/joule-code/joule-code-rs/crates/joule-moq-web/web/binding/sink.js

// WAI's browser sink (extensions/browser-sink.md) in this page, as `wai conform sink --suite
// browser` holds a sink to its corpus (live-conformance/browser, §12): each call is given with
// its answer withheld, and the page answers it with its own code, the normative parts by
// wai-live-web's wasm (`routeReport`, `chooseReport`, `evaluateConstraints`, `readBinding`,
// `frameTier`, `frameState`) and the side table by the page's own JavaScript
// (web/room/binding.js, `runSequence`). The answer is an object of the members the corpus states
// for the call's family, written as one JSON text in RFC 8785 form and a line feed.
//
// e2e/conform_sink.mjs drives this page in a browser and serves its answers to `wai conform`.
// Everything it reads is on `window.waiBrowserSink`: `ready` (a promise), `answer(call)` and
// `version`.

import initWai, * as wai from "../pkg/wai_live_web.js";
import { runSequence } from "../room/binding.js";

const parse = (s) => JSON.parse(s);
const text = (v) => JSON.stringify(v);

// A binding's canonical form (§7.1), as the page writes it into the side table.
const canonicalOf = (b) => parse(wai.readBinding(text(b))).canonical;

// The page's answer to one call: the members the corpus states for its family.
export function answer(call) {
  switch (call.call) {
    case "routes": {
      const r = parse(wai.routeReport(text(call.report)));
      return r.outcome === "routed" ? { outcome: r.outcome, reason: null, table: r.table } : { outcome: r.outcome, reason: r.reason, table: null };
    }
    case "choices": {
      const c = parse(wai.chooseReport(text(call.report)));
      if (c.outcome !== "chosen") return { outcome: c.outcome, reason: c.reason, table: null, choices: null };
      const r = parse(wai.routeReport(text(call.report)));
      return { outcome: c.outcome, reason: null, table: r.outcome === "routed" ? r.table : null, choices: c.choices };
    }
    case "constraints": {
      const e = parse(wai.evaluateConstraints(text(call.sets), text(call.params)));
      return { outcome: e.outcome, reason: e.reason };
    }
    case "bindings": {
      const b = parse(wai.readBinding(text(call.value)));
      return b.outcome === "read" ? { outcome: b.outcome, reason: null, canonical: b.canonical, tier: b.tier } : { outcome: b.outcome, reason: b.reason, canonical: null, tier: null };
    }
    case "frame_tiers":
      return { tier: wai.frameTier(call.route, call.route_tier, call.format_null, call.altered) };
    case "frames":
      return { result: parse(wai.frameState(text(call.binding), call.object, call.chain, call.provenance)) };
    case "tables":
      return { result: runSequence(call.bound, call.ops, canonicalOf) };
    default:
      throw new Error(`${call.call}: no call of this sink`);
  }
}

// RFC 8785: no insignificant whitespace, members sorted by their names' UTF-16 code units
// (JavaScript's own order of strings), and numbers and strings as ECMAScript writes them.
export function jcs(v) {
  if (v === null || typeof v !== "object") {
    if (typeof v === "number" && !Number.isFinite(v)) throw new Error(`${v}: a number RFC 8785 does not write`);
    if (v === undefined) throw new Error("undefined: not a JSON value");
    return JSON.stringify(v);
  }
  if (Array.isArray(v)) return `[${v.map(jcs).join(",")}]`;
  return `{${Object.keys(v).filter((k) => v[k] !== undefined).sort().map((k) => `${JSON.stringify(k)}:${jcs(v[k])}`).join(",")}}`;
}

const ready = initWai().then(() => true);

window.waiBrowserSink = {
  ready,
  version: navigator.userAgent,
  answer: (call) => `${jcs(answer(call))}\n`,
};