Provide Test Cases for Web3 1.0 Support

[ghost]

affects #3642 and MetaMask/web3-provider-engine#189

In order to clarify the implementation-requirements of the web3 1.0 support, test-cases should be provided.

The test-cases can be used for both web3 1.0 support implementation paths:

• Path A - via Websockets (see Add websocket subprovider web3-provider-engine#189)
• Path B - via polled-subprovider, see Add Web3 1.0 "subscription" support with a polling subprovider #3642

Step One

Provide simple js code files, which demonstrate the web3 1.0 access (which should fail)

from #3642 (comment)

// Importing the latest version from NPM
const Web3 = require('web3')

// initializing a local instance
const web3 = new Web3(window.web3.currentProvider)
web3.eth.subscribe('logs', {
  address: '0x86fa049857e0209aa7d9e616f7eb3b3b78ecfdb0',  // EOS token is popular atm.
  topics: [], // A token transfer log would be good for now.
}, function (err, result) {
  if (err) throw err
  console.log('Success!', result)
})

Step Two

Embed those code files into the MM test system.

Draft/Starting-Point: https://gist.github.com/ryan-rowland/54218bde11170734acb276a3564ac06b

References

from: #3618 (comment)

web3 original test-cases

https://github.com/ethereum/web3.js/blob/1.0/test/helpers/test.subscription.js
https://github.com/ethereum/web3.js/blob/1.0/test/eth.subscribe.js

Subscription relevant specs:

https://web3js.readthedocs.io/en/1.0/web3-eth-subscribe.html

[ryan-rowland]

Here are the tests web3.js is running against their own provider to test subscriptions:
https://github.com/ethereum/web3.js/blob/1.0/test/helpers/test.subscription.js
https://github.com/ethereum/web3.js/blob/1.0/test/eth.subscribe.js

And the specs for eth.subscribe(), eth.clearSubscriptions() and the Subscription object:
https://web3js.readthedocs.io/en/1.0/web3-eth-subscribe.html

[ryan-rowland]

Here's a first pass at a draft of Step A. Some of the actual tests are filled in, but toward the bottom there are some empty tests just outlining what needs to be validated.

https://gist.github.com/ryan-rowland/54218bde11170734acb276a3564ac06b

[ghost]

@ryan-rowland , very nice! I've updated the document. At this point it should be much easier for anyone to get started.

[ryan-rowland]

Running some tests locally using web3 on npm against rinkeby. Some of my initial assumptions were wrong, particularly regarding the subscribe callback. It actually runs every time a data event fires with (err, data, subscription). The web3 docs aren't very thorough in this regard.

I'll update later when I have time.

[ghost]

@ryan-rowland , i'm closing down here. For the case you still want to push this, just go on please.

follow-up MetaMask/web3-provider-engine#189 & #3642