viem/types/calls.ts

TypeScript Interface for Ethereum

import type { AbiStateMutability, Address } from 'abitype'
import type { Hex } from './misc.js'
import type { GetMulticallContractParameters } from './multicall.js'
import type { OneOf, Prettify } from './utils.js'

export type Call<
  call = unknown,
  extraProperties extends Record<string, unknown> = {},
> = OneOf<
  | (extraProperties & {
      data?: Hex | undefined
      to: Address
      value?: bigint | undefined
    })
  | (extraProperties &
      (Omit<
        GetMulticallContractParameters<call, AbiStateMutability>,
        'address'
      > & {
        to: Address
        value?: bigint | undefined
      }))
>

export type Calls<
  calls extends readonly unknown[],
  extraProperties extends Record<string, unknown> = {},
  ///
  result extends readonly any[] = [],
> = calls extends readonly [] // no calls, return empty
  ? readonly []
  : calls extends readonly [infer call] // one call left before returning `result`
    ? readonly [...result, Prettify<Call<call, extraProperties>>]
    : calls extends readonly [infer call, ...infer rest] // grab first call and recurse through `rest`
      ? Calls<
          [...rest],
          extraProperties,
          [...result, Prettify<Call<call, extraProperties>>]
        >
      : readonly unknown[] extends calls
        ? calls
        : // If `calls` is *some* array but we couldn't assign `unknown[]` to it, then it must hold some known/homogenous type!
          // use this to infer the param types in the case of Array.map() argument
          calls extends readonly (infer call extends OneOf<Call>)[]
          ? readonly Prettify<call>[]
          : // Fallback
            readonly OneOf<Call>[]

export type Batches<
  batches extends readonly { calls: readonly unknown[] }[],
  properties extends Record<string, any> = {},
  ///
  result extends readonly any[] = [],
> = batches extends readonly [infer batch extends { calls: readonly unknown[] }]
  ? [...result, { calls: Calls<batch['calls']> } & properties]
  : batches extends readonly [
        infer batch extends { calls: readonly unknown[] },
        ...infer rest extends readonly { calls: readonly unknown[] }[],
      ]
    ? Batches<
        [...rest],
        properties,
        [...result, { calls: Calls<batch['calls']> } & properties]
      >
    : batches