Getting Started

Start an ethereum node with testrpc or geth --rpc which listens on localhost:8585.

In HDMDLink project, run the CLI commands below:

truffle compile
truffle migrate
truffle console

In truffle, run this to allow the default account to invoke mint().

HDMDToken.deployed().then(function(instance){hdmd=instance});
hdmd.allowMinter(web3.eth.accounts[0]);

Then run this to get the contract address:

hdmd.address;

In this project, change the hdmdContractAddress in config.js.

Then run the CLI commands below:

npm install

cd "C:\Program Files\MongoDB\Server\3.4\bin\"
mongod.exe

npm start

You can interact with the API using curl (for Linux) or Postman (for Windows). Ensure that you select JSON (application/json) as the body format.

Unit Testing

We use Mocha as our unit-testing framework. To install, run the CLI command:

npm install -g --save-dev [email protected]

Troubleshooting

new BigNumber() not a base 16 number

• Cause: The contract probably doesn't exist at the address.
• Solution: Correct the address. You probably just need to uncomment the current address, and change the address for testRPC since another developer would use a different address.

Node app is frozen

• Cause: testRPC or geth process is locked. This occassionally occurs on Windows 10.
• Solution: You'll need to press any key in the Powershell console to unlock it. Alternatively, use CMD or VS Code Integrated Terminal.

Error when Minting

Error: invalid address
    at inputAddressFormatter (drive:\HDMDLink\node_modules\web3\lib\web3\formatters.js:273:11)

• Cause: The address of the wallet is not authorized to mint.
• Solution: Invoke the allowMinter function in truffle or other client where you are the contract owner, and pass the address of web3.eth.defaultAccount as a parameter. After that, the address should be allowed to invoke the mint function.

Error on Contribution Seed

Error: VM Exception while processing transaction: invalid opcode
    at batchTransfer

• Cause: The initial contribution needs to add up exactly to the balance of the account that you are transferring from. The contract only supports 8 decimal places, and due to roudning, you may end up transferring more than the available balance in your account.
• Solution: Ensure that your total transfer amount (in hdmdContributions.js) when rounded to 8 decimals does not result in exceeding the balance of the contract owner's account.

MongoDB query returns empty result

• Cause: Object names are case-sensitive in MongoDB, but the Moongoose package changes your collection names to lowercase.
• Solution: Check your casing.