Transition Registry

1// transition-registry.mjs — loader for this skill's vendored transition registry
2// (./transitions.json). The registry is the curated Tier-B subset (transform /
3// opacity / filter on the two frame clip wrappers `#el-<id>`, no overlay DOM) +
4// each type's GSAP template. Vendored into the skill so it ships standalone; the
5// recipes originate from the shared catalog skills/hyperframes-animation/
6// transitions/ (css-*.md) — keep them in step if those shared recipes change.
7
8import { readFileSync } from "node:fs";
9import { resolve, dirname } from "node:path";
10import { fileURLToPath } from "node:url";
11
12const here = dirname(fileURLToPath(import.meta.url));
13export const DEFAULT_REGISTRY_PATH = resolve(here, "./transitions.json");
14
15let _cache = null;
16
17export function loadTransitionRegistry(registryPath = DEFAULT_REGISTRY_PATH) {
18  if (_cache && _cache.path === registryPath) return _cache.data;
19  let data;
20  try {
21    data = JSON.parse(readFileSync(registryPath, "utf8"));
22  } catch (e) {
23    throw new Error(`transition registry not loadable at ${registryPath}: ${e.message}`);
24  }
25  if (!Array.isArray(data.transitions) || data.transitions.length === 0) {
26    throw new Error(`transition registry ${registryPath} has no transitions[]`);
27  }
28  _cache = { path: registryPath, data };
29  return data;
30}
31
32// Convenience: a Map name -> transition record.
33export function transitionsByName(registryPath = DEFAULT_REGISTRY_PATH) {
34  const data = loadTransitionRegistry(registryPath);
35  const map = new Map();
36  for (const t of data.transitions) map.set(t.name, t);
37  return map;
38}