Omitting optional sendTransaction parameters in ganache/truffle causes block ingestor errors

[timmclean]

Steps to reproduce from @nenadjaja :

Open multiple terminal tabs, and run the following in each one:

1. $ ganache-cli (or if you want the new, not released ganache, follow the steps here Problems getting blocks from Ganache #375
2. Pull this repo: https://github.com/graphprotocol/hackathon-scaffold and cd into the ethereum folder
3. Run $ truffle compile followed by truffle migrate --> it should give you the contract address under "Deploying Events"
4. Copy that address, and paste it into subgraph.yaml (subgraph manifest) inside of the hackathon-scaffold project
5. Start ipfs daemon in a separate terminal tab
6. Run createdb scaffold in another tab to create a database
7. Pull graph-node and run:

cargo run -p graph-node --release -- \
  --postgres-url postgresql://nevena@localhost:5432/scaffold \
  --ethereum-rpc testnet:http://127.0.0.1:8545 \
  --ipfs 127.0.0.1:5001 \
  --debug

8. Inside of your hackathon-scaffold folder, cd into subgraph and run yarn codegen followed by yarn deploy
9. Open a separate tab to access Truffle console by running truffle console --network development
10. In the truffle console, run the following to get some accounts: web3.eth.getAccounts().then(ethaccounts => accounts = ethaccounts)
11. Then run the following: web3.eth.sendTransaction({ from: accounts[0], to: accounts[1], value: web3.utils.toWei('10', "ether"),gas:50000})
12. Go back to your graph-node terminal tab, and you should get the following logs:

WARN Trying again after block polling failed: could not get latest block from Ethereum: Decoder error: Error("invalid type: null, expected a 0x-prefixed hex-encoded vector of bytes", line: 0, column: 0)

[timmclean]

It appears that the issue is specifically with the web3js "data" parameter being omitted. When a transaction is submitted to Ganache without a "data" parameter, Ganache will return that transaction from the JSON RPC interface with "input" set to null. This triggers a parsing error in the web3 crate. The JSON RPC spec does not seem to allow "input" to be null.

Submitting with "data": "0x" has the same result. "input" is still null. It seems like Ganache might be mapping empty byte strings to null.

Work around: avoid submitting transactions without a data parameter. Avoid submitting transactions with data set to empty byte string. Instead, provide a non-empty value such as data: "0x42".

[timmclean]

Filed trufflesuite/ganache#220 for the compatibility issue.

[timmclean]

Wow, issue seems to be fixed already on develop in ganache-core! trufflesuite/ganache#221

@nenadjaja can you confirm?

[nenadjaja]

Update
Tested with the following:

• new Ganache CLI release: ganache-cli 6.2.1 that's using ganache-core version 2.3.1
• Our hackathon-scaffold project with "@graphprotocol/graph-cli": "^0.4.1" and "@graphprotocol/graph-ts": "^0.4.1"

This issue is fixed and can't be reproduced anymore.