decentraland/mana

⏣ Solidity Contracts for the Decentraland MANA Token

Decentraland MANA Token

Solidity smart contracts for the Decentraland Crowdsale and MANA Token

mana's Issues

Implement PausableToken for MANA

The MANA token should be pausable

https://github.com/OpenZeppelin/zeppelin-solidity/blob/master/contracts/token/PausableToken.sol

Add Natural Specification comments

burnTokens() public

DO you want to allow the token holders to burn/destroy their tokens? Maybe you dont, I mean you want the tokens in circulation right? Would a user would want to destroy it?. In the case a account is hacked, and instead of draining the account the attacker decide to burn the tokens instead.

I dont understand 100% how you crowdsale will work, but if you need to destroy unsold tokens, you can allow only the crowdsale owner to do that.

If you want I can create the PR to let only the owner of the crowdsale burn tokens, let me know what you think :)

why DecentralandCrowdsale is no longer used?

why https://etherscan.io/address/0xa66d83716c7cfe425b44d0f7ef92de263468fb3d is no longer used?

processPurchase() && getRate()

processPurchase() in MANACrowdsale overrides the function in ContiniousCrowdsale, Instead of overriding that method you can add the function getRate() on the ConiousCrowdsale and only override that function, I understand that is the only thing that you want to do, provide different rates for special addresses, its not a bug, just a change on the code that you can do, and I think It will look better.

Also, why is getRate() internal? I think it can be public, so the investors can verify the rate they are going to have before sending eth.

If you want I can create the PR, let me know what you think :)

Consider adding comments on OpenZeppelin import versions

In MANACrowdsale.sol three contracts are imported from zeppelin-solidity, but there's no indication as to which versions they are.

This potentially complicates review.

Improve test coverage of ContinuousCrowdsale bucket logic

Overflow Analysis TODO Removal

Line 127 of MANACrowdsale.sol:

// TODO: possibility of overflow in these operations should be analized

should be removed as there is no possibility of overflow. uint256 can store numbers larger than 10^77.

The line also contains a typo: analized should be analyzed.

It's also worth noting that the interest in the next two lines is calculated linearly instead of exponentially.

Add test cases for Burn and RateChange events

Add explicit visibility specifiers to all functions

Helps prevent what happened to Parity multisig.

ContinuousCrowdsale should be called ContinuousSale

Burn: It should throw if the owner has no balance

mana/contracts/BurnableToken.sol

Line 18 in e39547e

address burner = msg.sender;

Change token name to "Decentraland Mana"

https://github.com/decentraland/mana/blob/master/contracts/MANAToken.sol#L10

Test script exits with success status code even when tests fail

This causes Travis to report that tests pass when they fail. There's an updated script in OpenZeppelin which fixes this.

https://github.com/OpenZeppelin/zeppelin-solidity/blob/master/scripts/test.sh

Split main crowdsale from continuous sale contract

We should transfer the ownership of the token once the main Crowdsale ends to a simpler contract that only handles the continuous issuance. This significantly reduces the attack surface of both contracts.

Broken hard cap for whitelisted investors

When a whitelisted investor is making a purchase the cap invariant check is skipped. This will allow a big whale investor to buy much more tokens than intended to be offered and put the whole crowd sale in jeopardy.

Test to demonstrate this bug:

it('whitelisted big whale investor should not exceed the cap', async function () {
    const cap = (await crowdsale.cap());
    const overCap = cap.mul(2);
    await crowdsale.addToWhitelist(investor);
    await crowdsale.buyTokens(investor, {value: overCap, from: investor}).should.be.rejectedWith(EVMThrow);
    const balance = await token.balanceOf(investor);
    const raised = await crowdsale.weiRaised();
    balance.should.be.bignumber.equal(0);
    raised.should.be.bignumber.most(cap);
  })

npm test not successful...

Hi,
I am a newbie in Ethereum contract programming. I am testing the code in an ubuntu machine with node, testrpc and truffle. Here is what I got after running "npm test"

reggie@UBC809:~/mana$ npm test

> [email protected] test /home/reggie/mana
> ./scripts/test.sh

Using existing testrpc instance
Compiling ./contracts/BurnableToken.sol...
Compiling ./contracts/ContinuousSale.sol...
Compiling ./contracts/MANAContinuousSale.sol...
Compiling ./contracts/MANACrowdsale.sol...
Compiling ./contracts/MANAToken.sol...
Compiling ./contracts/Migrations.sol...
Compiling ./contracts/WhitelistedCrowdsale.sol...
Compiling ./test/helpers/BurnableTokenMock.sol...
Compiling ./test/helpers/WhitelistedCrowdsaleImpl.sol...
Compiling zeppelin-solidity/contracts/crowdsale/CappedCrowdsale.sol...
Compiling zeppelin-solidity/contracts/crowdsale/Crowdsale.sol...
Compiling zeppelin-solidity/contracts/crowdsale/FinalizableCrowdsale.sol...
Compiling zeppelin-solidity/contracts/lifecycle/Pausable.sol...
Compiling zeppelin-solidity/contracts/math/SafeMath.sol...
Compiling zeppelin-solidity/contracts/ownership/Ownable.sol...
Compiling zeppelin-solidity/contracts/token/BasicToken.sol...
Compiling zeppelin-solidity/contracts/token/ERC20.sol...
Compiling zeppelin-solidity/contracts/token/ERC20Basic.sol...
Compiling zeppelin-solidity/contracts/token/MintableToken.sol...
Compiling zeppelin-solidity/contracts/token/PausableToken.sol...
Compiling zeppelin-solidity/contracts/token/StandardToken.sol...
Error: Error: Exceeds block gas limit
    at StateManager.queueTransaction (/usr/local/lib/node_modules/ethereumjs-testrpc/build/cli.node.js:90571:21)
    at GethApiDouble.eth_sendTransaction (/usr/local/lib/node_modules/ethereumjs-testrpc/build/cli.node.js:90071:14)
    at GethApiDouble.handleRequest (/usr/local/lib/node_modules/ethereumjs-testrpc/build/cli.node.js:89870:10)
    at next (/usr/local/lib/node_modules/ethereumjs-testrpc/build/cli.node.js:59378:18)
    at GethDefaults.handleRequest (/usr/local/lib/node_modules/ethereumjs-testrpc/build/cli.node.js:89767:12)
    at next (/usr/local/lib/node_modules/ethereumjs-testrpc/build/cli.node.js:59378:18)
    at FilterSubprovider.handleRequest (/usr/local/lib/node_modules/ethereumjs-testrpc/build/cli.node.js:65832:7)
    at next (/usr/local/lib/node_modules/ethereumjs-testrpc/build/cli.node.js:59378:18)
    at DelayedBlockFilter.handleRequest (/usr/local/lib/node_modules/ethereumjs-testrpc/build/cli.node.js:89595:3)
    at next (/usr/local/lib/node_modules/ethereumjs-testrpc/build/cli.node.js:59378:18)
    at Object.InvalidResponse (/home/reggie/mana/node_modules/truffle/build/cli.bundled.js:37047:16)
    at /home/reggie/mana/node_modules/truffle/build/cli.bundled.js:224634:36
    at XMLHttpRequest.request.onreadystatechange (/home/reggie/mana/node_modules/truffle/build/cli.bundled.js:223413:13)
    at XMLHttpRequestEventTarget.dispatchEvent (/home/reggie/mana/node_modules/truffle/build/cli.bundled.js:225286:18)
    at XMLHttpRequest._setReadyState (/home/reggie/mana/node_modules/truffle/build/cli.bundled.js:225576:12)
    at XMLHttpRequest._onHttpResponseEnd (/home/reggie/mana/node_modules/truffle/build/cli.bundled.js:225731:12)
    at IncomingMessage.<anonymous> (/home/reggie/mana/node_modules/truffle/build/cli.bundled.js:225691:24)
    at emitNone (events.js:91:20)
    at IncomingMessage.emit (events.js:188:7)
    at endReadableNT (_stream_readable.js:975:12)
npm ERR! Test failed.  See above for more details.
reggie@UBC809:~/mana$ node -v
v7.9.0
reggie@UBC809:~/mana$ npm -v
5.6.0

I don't have enough gas on testrpc?

Add proper license

Also, identify code stealed copied from OpenZeppelin.

Fix failing whitelist-related test cases

Use SafeMath in MANACrowdsale.sol Constructor Function

Line 44:

require(_rate > _rateStepDecrease * (_endBlock - _startBlock));

and line 78 of MANACrowdsale.sol:

return rate.sub(rateStepDecrease.mul(block.number - startBlock));

should use SafeMath functions to be consistent with the rest of the codebase.

Specifically, line 44 should be changed to:

require(_rate > _rateStepDecrease.mul(_endBlock.sub(_startBlock)));

and line 78 should be changed to:

return rate.sub(rateStepDecrease.mul(block.number.sub(startBlock)));

Off by one error in rateStepDecrease precondition

Since endBlock is inclusive, MANACrowdsale.sol:44 should read:

require(_rate > _rateStepDecrease * (1 + _endBlock - _startBlock));