Setting up a development environment for smart contracts
Some rough notes on using truffle to develop and manually test.
First install truffle and make a new project
npm install -g truffle mkdir foo && cd foo truffle init
Install deps
npm install @openzeppelin/contracts
Edit the contract
Save it and then...
* Compile (truffle compile)
Create new script in the migrations folder
like migrations/2_foo.js file to select contract
run "truffle develop"
Stash the account list and private keys that show up when you start the console somewhere useful
migrate the contract "migrate"
instantiate
x = await Foo.deployed()
use (hint: use accounts[n] to access account ids.)
metamask:
add new network (RPC url is http://127.0.0.1:9545, chain ID is 1337)
Add some accounts (account 0 is the default admin)
Writing JS:
in truffle developer console, get the address
foo = await Foo.deployed(); foo.address
And get the ABI from the truffle project in build/contracts/*.json
HINT: may want to assign names to the return values if many.
Common Errors:
Failed transaction due to "incorrect nonce": Reset your account in metamask.
Returned values aren't valid, did it run Out of Gas?: don't forget to migrate after launching truffle again.
ABI generated by truffle doesn't properly name outputs: if you use outputs by name in web3, be sure to update the abi to name them