michellekwa / canoe-solidity

Lightweight Javascript library for decoding constructor arguments.

🛶 Canoe Solidity

Lightweight Javascript library for decoding constructor arguments.

Summary

Canoe works by reading a contract's ABI and decoding the constructor bytecode with the argument types provided.

Install

npm install canoe-soldity

Requirements

• ABI schema 2.0

Documentation

Functions

decodeConstructorArgs(contractABI, bytecode) ⇒ Object

Decodes constructor args.

encodeConstructorArgs(inputs) ⇒ string

Generates constructor args bytecode based on input data.

decodeConstructorArgs(contractABI, bytecode) ⇒ Object

Decodes constructor args.

Kind: global function
Returns: Object - decodedArgs - Object representing decoded args with name, type, and data fields

Param	Type	Description
contractABI	Object	ABI of contract whose args to decode
bytecode	string	Constructor args bytecode

encodeConstructorArgs(inputs) ⇒ string

Generates constructor args bytecode based on input data.

Kind: global function
Returns: string - bytecode - Constructor args bytecode

Param	Type	Description
inputs	Array.<Object>	Array of objects with name, and type fields
inputs[].name	string	Name of argument
inputs[].type	string	Type of argument

Supported Types

• bool
• uint
• int
• fixed
• address
• bytes1, bytes2, bytes3, ..., bytes32
• byte
• string
• arrays
• multi-dimensional arrays
• mapping
• struct

Example

const { decodeConstructorArgs } = require('canoe-solidity');
let abiExample = {
  'abi': [
    {
      'anonymous': false,
      'inputs': [
        {
          'name': 'addresses',
          'type': 'address[]',
        },
        {
          'name': 'quantities',
          'type': 'uint256[]',
        },
        {
          'name': '_creationUnit',
          'type': 'uint256',
        },
        {
          'name': '_name',
          'type': 'string',
        },
        {
          'name': '_symbol',
          'type': 'string',
        }
      ],
      'payable': false,
      'stateMutability': 'nonpayable',
      'type': 'constructor'
    }
  ];
};
let bytecodeExample = '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';
decodeConstructorArgs(abiExample.abi, bytecodeExample);

Output:

[
  {
    "name": "addresses",
    "type": "address[]",
    "data": [
      "ffffffffffffffffffffffffffffffffffffffff",
      "f1e48f13768bd8114a530070b43257a63f24bb12"
    ]
  },
  {
    "name": "quantities",
    "type": "uint256[]",
    "data": [
      "5",
      "10"
    ]
  },
  {
    "name": "_creationUnit",
    "type": "uint256",
    "data": "10000000000000000000"
  },
  {
    "name": "_name",
    "type": "string",
    "data": "Ethereum10 Q2-2018"
  },
  {
    "name": "_symbol",
    "type": "string",
    "data": "E10"
  }
]