Add eth_chainId RPC endpoint

[davidmurdoch]

https://github.com/ethereumproject/go-ethereum/wiki/JSON-RPC#eth_chainid

[fireblockdev]

After discussion with nivida from web3js, this method is needed to use ganache with web3js.

[fireblockdev]

I did the same but he didn't fix the problem for me. I changed the web3 version in package.json and try to run the tests but the Web3() constructor crashes.

[biocrypto730]

Thank you @tcichowicz for not being a psycho capitalist

[biocrypto730]

@davidmurdoch Is this issue closed now with the push today? Tcichowicz code should be merged right? It is bad that ganache and the latest version of Web3 Don't work together

[lucashenning]

Any update on this? The issue in the web3.js repo has been closed (web3/web3.js#2610) but I'm still getting the same error in web3 1.0.0-beta.55 and Ganache 2.0.2-beta.0 (2.0.2-beta.0.648).

{"message":"Method eth_chainId not supported.","code":-32000,"data":{"stack":"Error: Method eth_chainId not supported.\n    at GethApiDouble.handleRequest (/Applications/Ganache.app/Contents/Resources/app.asar/node_modules/ganache-core/lib/subproviders/geth_api_double.js:67:16)\n    at next (/Applications/Ganache.app/Contents/Resources/app.asar/node_modules/ganache-core/node_modules/web3-provider-engine/index.js:116:18)

[imbenwolf]

@davidmurdoch please review #419 so we can finally use latest web3 and ganache versions together

[davidmurdoch]

I've hesitated adding this as the value it returns should be configurable. I'll go ahead and merge this into develop now regardless and follow up with a new Issue to add a chain_id configuration option to core, cli, and UI.

Thanks for keeping on top of this @imbenwolf and @lucashenning!

Aside, it may be worth it to know that web3@beta.37 is the version of web3 that will be released as stable. PR here: web3/web3.js#2905

[davidmurdoch]

Followup issue: #441

Thanks again!