type InterfaceAbi: string | ReadonlyArray<Fragment | JsonFragment | string>;
An InterfaceAbi may be any supported ABI format. A string is expected to be a JSON string, which will be parsed using JSON.parse. This means that the value must be a valid JSON string, with no stray commas, etc. An array may contain any combination of:
  • Human-Readable fragments
  • Parsed JSON fragment
  • Fragment
A Human-Readable Fragment is a string which resembles a Solidity signature and is introduced in this blog entry. For example, function balanceOf(address) view returns (uint). A Parsed JSON Fragment is a JavaScript Object desribed in the Solidity documentation.

​
Source

abi/interface.ts:298