Introspection

One-shot questions about a form without creating a store: which fields exist under these choices, what would a field's options be, which branches carry a key. Every helper runs the REAL resolver over pinned values — everything unpinned falls to its default — so the answers are exact, not a structural guess at conditions a walker can't evaluate.

import {
  fieldKeys, hasField, fieldMeta, optionsFor,
  enumerateBranches, whereFieldExists, allPossibleKeys,
} from 'form-graph';

// "Pins" are the choices you fix; the resolver decides the rest.
fieldKeys(form, { mode: 'upscale' }, ext);
// -> ['mode', 'prompt', 'scale']

hasField(form, 'steps', { mode: 'upscale' }, ext);   // -> false

fieldMeta(form, 'model', { workflow: 'txt2img', ecosystem: 'A' }, ext);
// -> that field's resolved meta under those pins (catalog, defaults, locks)

optionsFor(form, 'mode', {}, ext);
// -> candidate values, read from the field's own meta.options

Walking the branch space

enumerateBranches expands the form's discriminant fields (the axes, in order) over their own option lists and returns one entry per reachable combination. An axis that isn't active under the current pins is skipped, so branches where a later discriminant never appears terminate early instead of needing a special case.

enumerateBranches(form, ['workflow', 'ecosystem'], ext);
// -> [ { pins: { workflow: 'txt2img', ecosystem: 'A' }, keys: [...] }, ... ]

whereFieldExists(form, 'sourceImage', ['workflow', 'ecosystem'], ext);
// -> only the combinations whose branch carries the field —
//    "which workflows accept image input?" without a hard-coded list

allPossibleKeys(form, ['workflow', 'ecosystem'], ext);
// -> every field key reachable through those axes

What it's for

• Capability matrices — a picker that must know, before switching, whether the target branch supports the current inputs.
• Tests — assert branch membership and option lists across the whole space in a loop, instead of one hand-written case per combination.
• Static generation — enumerate every branch at build time and prerender a page or an index per combination.

Scoping is ignored on purpose: introspection is one-shot resolution with no intent, so scope declarations don't change the answers.