I deployed a ERC20Mintable token in truffle env(the .sol file is ERC20Mintable.sol).

   Deploying 'ERC20Mintable'
   > transaction hash:    0x02c7b8e1dbde226304614ceeea48e1d4eb123bd1a70e73b1955d8718f3d49e08
   > Blocks: 0            Seconds: 0
   > contract address:    0x25CcB91c6643a0679591F888c3a16B12745b9594
   > block number:        3
   > block timestamp:     1562326476
   > account:             0x6D04f90886E0651381c174B2752C6c0F06626a54
   > balance:             99.96399902
   > gas used:            1496633
   > gas price:           20 gwei
   > value sent:          0 ETH
   > total cost:          0.02993266 ETH
   > Saving migration to chain.
   > Saving artifacts
   > Total cost:          0.02993266 ETH

the 2_mintable.js code is:

const ERC20Mintable = artifacts.require("ERC20Mintable.sol");
module.exports = function(deployer) {

I want to check whether accounts[0] is minter, and call function as below:

let instance = await ERC20Mintable.deployed()//It can display correct contract info.
let accounts = await web3.eth.getAccounts()

there is an error information like below, how to fix the problem, many thanks!

truffle(develop)> instance.MinterRole.isMinter(accounts[0])

TypeError: Cannot read property 'isMinter' of undefined
    at evalmachine.<anonymous>:0:21
    at sigintHandlersWrap (vm.js:285:15)
    at Script.runInContext (vm.js:127:14)
    at runScript (/usr/local/lib/nodejs/node-v10.15.3-linux-x64/lib/node_modules/truffle/build/cli.bundled.js:368533:21)
    at Console.interpret (/usr/local/lib/nodejs/node-v10.15.3-linux-x64/lib/node_modules/truffle/build/cli.bundled.js:368548:21)
    at ReplManager.interpret (/usr/local/lib/nodejs/node-v10.15.3-linux-x64/lib/node_modules/truffle/build/cli.bundled.js:369389:18)
    at bound (domain.js:395:14)
    at REPLServer.runBound [as eval] (domain.js:408:12)
    at REPLServer.onLine (repl.js:639:10)
    at REPLServer.emit (events.js:189:13)
  • do you need .MinterRole between instance and isMinter(accounts[0]) ?
    – Majd TL
    Jul 5, 2019 at 12:30
  • I need assign a miner address,for instance,accounts[0]. but from the source code, I can not found how to do it.
    – user53451
    Jul 7, 2019 at 2:07

1 Answer 1


Read the top of the ERC20Mintable.sol file (which you have linked at the top of your own question):

contract ERC20Mintable is ERC20, MinterRole ...

Contract ERC20Mintable IS MinterRole (in contrast with HAS MinterRole).

This mean that ERC20Mintable inherits all the (non-private) functions and variables of MinterRole.

Hence you should call the function directly:

  • Thanks, It works now. Function instance.isMinter() will return correct value. the accounts[0] is miner, the other nince accounts are not. But when I try to call instance.mint(accounts[1],1000), it also can mint coin.The minted coin will be go into account[1]. I can not understand why it happens even the mint() function has modifer onlyMinter. so how to control the right who can call mint() function indeed? Thanks for your help.
    – user53451
    Jul 7, 2019 at 4:50
  • @Ntydrm: This sounds like a completely different problem, so I suggest that you post it as a separate question. Jul 7, 2019 at 6:11
  • Done.Thanks for you comment.The link for new question is ethereum.stackexchange.com/questions/72667/…
    – user53451
    Jul 8, 2019 at 1:44

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