Include web3 middleware in ENS.fromWeb3()

[fselmo]

What was wrong?

From recent comments on issue #425:

• ENS.fromWeb3() does not make use of existing middlewares present in the Web3 instance that is passed in to the method. This led to issues using geth_poa_middleware.

Closes #1657

How was it fixed?

• Inherit the Web3 instance's middlewares when instantiating the ENS instance from a Web3 instance.
• Adds a middlewares property to the NamedElementOnion data structure / web3.middleware_onion that returns a list of all current middlewares in appropriate order to be passed in to a new Web3 instance.

Todo:

• Add entry to the release notes

Cute Animal Picture

[wolovim]

LGTM! 🚢

[kclowes]

This is a breaking change if someone was passing the address as the second param without the keyword before. Is it important for middlewares to be the second arg? Sorry I wasn't there for the review yesterday!

[KaiRo-at]

Note that now I do get an exception in my code that I did not get before, see partial stack here (ns has been created by ENS.fromWeb3() with a web3 object that has caching middleware applied):

[...]
    ensname = ns.name(address)
  File "/usr/local/lib/python3.10/site-packages/ens/main.py", line 150, in name
    return self.resolve(reversed_domain, get='name')
  File "/usr/local/lib/python3.10/site-packages/ens/main.py", line 241, in resolve
    resolver = self.resolver(normal_name)
  File "/usr/local/lib/python3.10/site-packages/ens/main.py", line 253, in resolver
    resolver_addr = self.ens.caller.resolver(normal_name_to_hash(normal_name))
  File "/usr/local/lib/python3.10/site-packages/web3/contract.py", line 1453, in call_function
    return fn(*args, **kwargs).call(transaction, block_identifier)
  File "/usr/local/lib/python3.10/site-packages/web3/contract.py", line 957, in call
    return call_contract_function(
  File "/usr/local/lib/python3.10/site-packages/web3/contract.py", line 1501, in call_contract_function
    return_data = web3.eth.call(
  File "/usr/local/lib/python3.10/site-packages/web3/module.py", line 57, in caller
    result = w3.manager.request_blocking(method_str,
  File "/usr/local/lib/python3.10/site-packages/web3/manager.py", line 197, in request_blocking
    response = self._make_request(method, params)
  File "/usr/local/lib/python3.10/site-packages/web3/manager.py", line 150, in _make_request
    return request_func(method, params)
  File "/usr/local/lib/python3.10/site-packages/web3/middleware/stalecheck.py", line 62, in middleware
    latest = web3.eth.get_block('latest')
  File "/usr/local/lib/python3.10/site-packages/web3/eth.py", line 642, in get_block
    return self._get_block(block_identifier, full_transactions)
  File "/usr/local/lib/python3.10/site-packages/web3/module.py", line 57, in caller
    result = w3.manager.request_blocking(method_str,
  File "/usr/local/lib/python3.10/site-packages/web3/manager.py", line 197, in request_blocking
    response = self._make_request(method, params)
  File "/usr/local/lib/python3.10/site-packages/web3/manager.py", line 150, in _make_request
    return request_func(method, params)
  File "/usr/local/lib/python3.10/site-packages/web3/middleware/stalecheck.py", line 68, in middleware
    return make_request(method, params)
  File "/usr/local/lib/python3.10/site-packages/cnp/capa_eth1.py", line 1163, in middleware
    response = make_request(method, params)
  File "/usr/local/lib/python3.10/site-packages/web3/middleware/cache.py", line 135, in middleware
    return make_request(method, params)
  File "/usr/local/lib/python3.10/site-packages/web3/middleware/cache.py", line 422, in middleware
    _update_block_info_cache()
  File "/usr/local/lib/python3.10/site-packages/web3/middleware/cache.py", line 408, in _update_block_info_cache
    block_info['latest_block'] = web3.eth.get_block('latest')
  File "/usr/local/lib/python3.10/site-packages/web3/eth.py", line 642, in get_block
    return self._get_block(block_identifier, full_transactions)
  File "/usr/local/lib/python3.10/site-packages/web3/module.py", line 57, in caller
    result = w3.manager.request_blocking(method_str,
  File "/usr/local/lib/python3.10/site-packages/web3/manager.py", line 197, in request_blocking
    response = self._make_request(method, params)
  File "/usr/local/lib/python3.10/site-packages/web3/manager.py", line 150, in _make_request
    return request_func(method, params)
  File "/usr/local/lib/python3.10/site-packages/web3/middleware/stalecheck.py", line 68, in middleware
    return make_request(method, params)
  File "/usr/local/lib/python3.10/site-packages/cnp/capa_eth1.py", line 1163, in middleware
    response = make_request(method, params)
  File "/usr/local/lib/python3.10/site-packages/web3/middleware/cache.py", line 135, in middleware
    return make_request(method, params)
  File "/usr/local/lib/python3.10/site-packages/web3/middleware/cache.py", line 422, in middleware
    _update_block_info_cache()
  File "/usr/local/lib/python3.10/site-packages/web3/middleware/cache.py", line 387, in _update_block_info_cache
    ancestor_block = web3.eth.get_block(ancestor_block_number)
  File "/usr/local/lib/python3.10/site-packages/web3/eth.py", line 642, in get_block
    return self._get_block(block_identifier, full_transactions)
[...]
RecursionError: maximum recursion depth exceeded while calling a Python object

I seem to only get this problem with the ENS lookup, not with using the normal Web3 object with the caching middleware.