Function encodeKeys

packages/effect/src/Schema.ts:3664–3696

(mapping: M)

 * @since 4.0.0
 */
export function encodeKeys<
  S extends Constraint & { readonly fields: Struct.Fields },
  const M extends { readonly [K in keyof S["fields"]]?: PropertyKey }
>(mapping: M) {
  return function(self: S): encodeKeys<S, M> {
    const fields: any = {}
    const appliedMapping: any = Object.create(null)
    const reverseMapping: any = Object.create(null)
    const seenEncodedKeys = new Set<string | symbol>()
    for (const k of Reflect.ownKeys(self.fields)) {
      const encoded = toEncoded(self.fields[k])
      const hasMapping = Object.hasOwn(mapping, k)
      const encodedKey = hasMapping ? (mapping as any)[k] as PropertyKey : k
      const canonical = canonicalPropertyKey(encodedKey)
      if (seenEncodedKeys.has(canonical)) {
        throw new globalThis.Error(`Duplicate encoded keys: ${formatPropertyKey(encodedKey)}`)
      }
      seenEncodedKeys.add(canonical)
      InternalRecord.assignProperty(fields, encodedKey, encoded)
      if (hasMapping) {
        appliedMapping[k] = encodedKey
        reverseMapping[encodedKey] = k
      }
    }
    return Struct(fields).pipe(decodeTo(
      self,
      SchemaTransformation.transform<any, any>({
        decode: Struct_.renameKeys(reverseMapping),
        encode: Struct_.renameKeys(appliedMapping)
      })
    )) as any
  }
}

/**
 * Adds derived fields to a struct schema during decoding.