bs-eth

Really Basic ReasonML web3 like interface

The goal is for this to support most common web3 functionality in ReasonML as well as some less common functionality that I need.

I am currently learning ReasonML and using this as an exercise at implementing something I understand fairly well (web3) using ReasonMl.

This means the API is likely going to change a lot as I learn more about idiomatic ReasonML and fix stupid beginners mistakes.

Setting up a Provider

There is currently support for the following providers that both live in the Providers namespace:

• Providers.web3(web3provider) which wraps an existing web3 provider eg. MetaMask
• Providers.http(url) which is configured with a url to a http based provider like infura

Once you have a provider you pass it as a parameter to all the functions in the Eth namespace.

let provider = Providers.http("https://mainnet.infura.io/bs-eth");
netVersion(provider)
|> Repromise.wait(result => switch (result) {
| Ok(netId) => Js.log("we are on the " ++ string_of_int(netId) ++ " chain")
| Error(msg) => Js.log(msg)
});

Calling functions

All functions in the Eth module return typed Belt.Result in a Repromise. So instead of looking out for rejected calls, do a pattern match.

See the List of Methods implemented for more details.

Roadmap

• Fetch based https provider interface
• Wrap javascript Web3 provider (a la metamask)
• Most common JSON-RPC methods implemented (In bold below)
• Basic Documentation
• Solidity ABI codec in native reasonml
• Add support for WebSocket provider
• Filter support with support for some sort of reactive streams. Maybe wonka
• Implement complete wrappers for the JSON-RPC apps methods listed below
• EIP 712 support
• Add RLP encoder to be able to encode transactions for signing
• Allow signing in ReasonML using WASM
• Support for bs-native

Ethereum JSON-RPC Implemented Methods

The RPC methods currently implemented are:

• eth_accounts as accounts()
• eth_blockNumber as blockNumber()
• eth_call as call()
• eth_coinbase as coinbase()
• eth_estimateGas as estimateGas()
• eth_gasPrice as gasPrice()
• eth_getBalance as balanceOf()
• eth_getBlockByNumber as blockByNumber
• eth_getBlockByHash as blockByHash
• eth_getBlockTransactionCountByHash
• eth_getBlockTransactionCountByNumber
• eth_getCode
• eth_getCompilers
• eth_getFilterChanges
• eth_getFilterLogs
• eth_getLogs
• eth_getStorageAt
• eth_getTransactionByHash as transactionByHash()
• eth_getTransactionByBlockHashAndIndex
• eth_getTransactionByBlockNumberAndIndex
• eth_getTransactionCount as transactionCount()
• eth_getTransactionReceipt as `transactionReceipt()
• eth_hashrate
• eth_mining
• eth_newBlockFilter
• eth_newFilter (includes log/event filters)
• eth_protocolVersion
• eth_sendTransaction as sendTransaction()
• eth_sendRawTransaction as sendRawTransaction()
• eth_subscribe (only for websocket connections. "syncing" subscriptions are not yet supported)
• eth_unsubscribe (only for websocket connections. "syncing" subscriptions are not yet supported)
• eth_syncing
• eth_uninstallFilter
• net_listening
• net_peerCount
• net_version as netVersion()

Non-Standard ganache-cli methods:

• evm_snapshot
• evm_revert
• evm_increaseTime
• evm_mine as mineBlock()