Add type hints to `eth.tools.builder` modules

[pipermerriam]

What is wrong?

The eth.tools.builder module is not type hinted. This makes using it in the trinity module not possible.

How can it be fixed

Add type hints.

[Bhargavasomu]

Are the type hints needed for only the Functions or even the arguments to the function need to be type hinted?

[pipermerriam]

The whole module, functions, arguments, and anything else mypy complains about should be type hinted.

[Bhargavasomu]

Is there any easy way to find the types of the variables, or is it just by looking at the variables, we have to decide?

[cburgdorf]

Is there any easy way to find the types of the variables, or is it just by looking at the variables, we have to decide?

There are tools such as MonkeyType but I'd recommend to just add them by hand. However, sometimes using reveal_type and reveal_locals can help to unveil what mypy thinks some types are. Just drop in reveal_type(some_variable) or reveal_locals and then run mypy.

For instance:

class Foo:
    pass

class Bar:
    pass

x = 1
y = "Foo"

foo = Foo()
bar = Bar()

reveal_locals()

Running mypy on this gives me:

reveal_locals.py:13: error: Revealed local types are:
reveal_locals.py:13: error: bar: reveal_locals.Bar
reveal_locals.py:13: error: foo: reveal_locals.Foo
reveal_locals.py:13: error: x: builtins.int
reveal_locals.py:13: error: y: builtins.str

[Bhargavasomu]

@cburgdorf using reveal_locals or reveal_type is only givng the type as Any for all the definitions, since none of them are hinted anywhere. So I don't think that it is useful for this purpose.

[cburgdorf]

@Bhargavasomu This was more a general advice on how to work your way through with mypy. It obviously only works in scenarios where mypy can already infer a lot of the types. E.g. in the (trivial) example that I gave there are no type hints either, yet mypy inferred all types correctly.

[Bhargavasomu]

@cburgdorf I added the hints for most of the functions, but I am still getting the same error when I do this.
mypy --follow-imports=silent --ignore-missing-imports --no-strict-optional --check-untyped-defs --disallow-incomplete-defs --disallow-untyped-defs --disallow-any-generics scripts/benchmark

The error is as follows
scripts/benchmark/utils/chain_plumbing.py:80 error: Cannot call function of unknown type
The error is still occurring even though I added the type hints. So I ran the following command
mypy --follow-imports=silent --ignore-missing-imports chain_plumbing.py
I got no error while doing the above command, but got the error only when executing the whole benchmarks altogether.
Is there something that we could infer from this?

[Bhargavasomu]

This issue can be closed as it has been taken care of in #1420