AbiFunction

Utilities & types for working with Functions on ABIs.

AbiFunction is a sub-type of AbiItem.

Examples

Below are some examples demonstrating common usages of the AbiFunction module:

Instantiating via JSON ABI

An AbiFunction can be instantiated from a JSON ABI by using AbiFunction.fromAbi:

import { Abi, AbiFunction } from 'ox'
 
const abi = Abi.from([
  'function foo()',
  'event Transfer(address owner, address to, uint256 tokenId)',
  'function bar(string a) returns (uint256 x)',
])
 
const 
const item: {
    ...;
}item = AbiFunction.fromAbi(abi, 'bar')

Instantiating via Human-Readable ABI Item

An AbiFunction can be instantiated from a human-readable ABI by using AbiFunction.from:

import { AbiFunction } from 'ox'
 
const bar = AbiFunction.from('function bar(string a) returns (uint256 x)')
 
const bar: {
    readonly name: "bar";
    readonly type: "function";
    readonly stateMutability: "nonpayable";
    readonly inputs: readonly [{
        readonly type: "string";
        readonly name: "a";
    }];
    readonly outputs: readonly [{
        readonly type: "uint256";
        readonly name: "x";
    }];
}bar

Encoding to Function Data

A Function and its arguments can be ABI-encoded into data using the AbiFunction.encodeData function. The output of this function can then be passed to eth_sendTransaction or eth_call as the data parameter.

import { AbiFunction } from 'ox'
 
const approve = AbiFunction.from('function approve(address, uint256)')
 
const data = AbiFunction.encodeData(
  approve,
  ['0xd8da6bf26964af9d7eed9e03e53415d37aa96045', 69420n]
)
'0x095ea7b3000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa960450000000000000000000000000000000000000000000000000000000000010f2c'

Decoding a Function's Result

A Function's result can be ABI-decoded using the AbiFunction.decodeResult function.

import { AbiFunction } from 'ox'
 
const data = '0x000000000000000000000000000000000000000000000000000000000000002a'
//    ↑ Example data that could be returned from a contract call via `eth_call`.
 
const totalSupply = AbiFunction.from('function totalSupply() returns (uint256)')
 
const output = AbiFunction.decodeResult(totalSupply, data)
42n

Functions

Name	Description
`AbiFunction.decodeData`	ABI-decodes function arguments according to the ABI Item's input types (`inputs`).
`AbiFunction.decodeResult`	ABI-decodes a function's result according to the ABI Item's output types (`outputs`).
`AbiFunction.encodeData`	ABI-encodes function arguments (`inputs`), prefixed with the 4 byte function selector.
`AbiFunction.encodeResult`	ABI-encodes a function's result (`outputs`).
`AbiFunction.format`	Formats an `AbiFunction.AbiFunction` into a Human Readable ABI Function.
`AbiFunction.from`	Parses an arbitrary JSON ABI Function or Human Readable ABI Function into a typed `AbiFunction.AbiFunction`.
`AbiFunction.fromAbi`	Extracts an `AbiFunction.AbiFunction` from an `Abi.Abi` given a name and optional arguments.
`AbiFunction.getSelector`	Computes the 4-byte selector for an `AbiFunction.AbiFunction`.

Errors

Name	Description
`AbiFunction.SelectorMismatchError`	Thrown when the selector of the provided data does not match the selector of the function, or of one of its overloads.

Types

Name	Description
`AbiFunction.AbiFunction`	Root type for an `AbiItem.AbiItem` with a `function` type.
`AbiFunction.ExtractNames`
`AbiFunction.FromAbi`	Extracts an `AbiFunction.AbiFunction` item from an `Abi.Abi`, given a name.
`AbiFunction.Name`	Extracts the names of all `AbiFunction.AbiFunction` items in an `Abi.Abi`.