arround freeze sendTransaction.

miner_stop_correct_test.js

const pify = require('pify')

async function queueTransaction(from, to, value, nonce, gasLimit, data) {
    const response = await pify(web3.currentProvider.send)({
        jsonrpc: "2.0",
        method: "eth_sendTransaction",
        id: new Date().getTime(),
        params: [
          {
            from: from,
            to: to,
            gas: gasLimit,
            value: value,
            nonce: nonce,
            data: data
          }
        ]
      });
      if (response.error) {
        throw new Error(response.error.message);
    }
    return response.result;
}

it('multi transfer in same block', async () => {
  web3.extend({property: 'mine', methods: [{ name: 'start', call: 'miner_start', params:0}]})
  web3.extend({property: 'mine', methods: [{ name: 'stop', call: 'miner_stop', params:0}]})

  const instance = await MyERC20Token.new()
  const beforeBlock = await web3.eth.getBlockNumber()
  const nonce = await web3.eth.getTransactionCount(accounts[0])

  await web3.mine.stop()
  
  const tx1_data = instance.contract.methods.transfer(accounts[1], 100).encodeABI()
  const tx2_data = instance.contract.methods.transfer(accounts[2], 100).encodeABI()
  // queued tx1
  await queueTransaction(owner, Instance.address, 0, nonce, gas, tx1_data)
  // queued tx2
  await queueTransaction(owner, Instance.address, 0, nonce+1, gas, tx2_data)

  await web3.mine.start()
  const afterBlock = await web3.eth.getBlockNumber();

  assert.equal(beforeBlock+1, afterBlock) // block increase just +1.
  assert.equal(await Instance.balanceOf(accounts[1]), 100)
  assert.equal(await Instance.balanceOf(accounts[2]), 100)
})