Function computeOverrides

scripts/generate-fal-image-field-map.ts:214–246

(
  endpoints: Map<string, EndpointFields>,
)

]

function computeOverrides(
  endpoints: Map<string, EndpointFields>,
): Map<string, Partial<Record<RoleKey, string>>> {
  const overrides = new Map<string, Partial<Record<RoleKey, string>>>()

  for (const [endpointId, { fields, isList, producesVideo }] of endpoints) {
    const entry: Partial<Record<RoleKey, string>> = {}
    for (const role of ROLE_ORDER) {
      if (VIDEO_ONLY_ROLES.has(role) && !producesVideo) continue
      const chosen = CANDIDATES[role].find((candidate) => fields.has(candidate))
      if (!chosen) continue

      // Arity sanity check: the runtime mapper decides array-wrapping from
      // the static LIST_FIELDS set, so the actual type must agree. Run this
      // for default-selected fields too, otherwise a default field's type
      // could drift silently.
      const actualIsList = isList.get(chosen) ?? false
      const assumedIsList = LIST_FIELDS.has(chosen)
      if (actualIsList !== assumedIsList) {
        throw new Error(
          `Arity mismatch for ${endpointId}.${chosen}: type says ` +
            `${actualIsList ? 'array' : 'scalar'} but LIST_FIELDS assumes ` +
            `${assumedIsList ? 'array' : 'scalar'}. Update LIST_FIELDS here ` +
            `and LIST_FIELDS in image-inputs.ts.`,
        )
      }
      if (chosen === DEFAULTS[role]) continue
      entry[role] = chosen
    }
    if (Object.keys(entry).length > 0) overrides.set(endpointId, entry)
  }
  return overrides
}

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// Emission