🛶 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-solidity

Requirements

• ABI schema 2.0

Documentation

Functions

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 |

decodeFunctionArgs(contractABI, bytecode) ⇒ Object

Decodes function 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 | function args bytecode, methohID included |

Supported Types

• [x] bool
• [x] uint
• [x] int
• [ ] fixed
• [x] address
• [x] bytes1, bytes2, bytes3, ..., bytes32
• [x] byte
• [x] string
• [x] 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"
  }
]