add ffi cheatcode

[luksgrin]

This PR contains the implementation of Foundry's function ffi(string[] calldata) external returns (bytes memory); cheatcode with some helper functions and some code refactoring. See ffi's documentation here.

Dependencies added

• Python's native subprocess module

[luksgrin]

I am aware that both extract_string_argument and extract_string_array_argument share a lot of logic. But I did not want to risk breaking extract_string_argument for a silly refactoring...

[daejunpark]

Great contribution! To help us review, could you please add tests for this cheatcode? Also, could you disable the ffi cheatcode by default (for security reasons), and add an option to enable it? Thank you!

[luksgrin]

@daejunpark Please let me know if the tests I added are enough. I wanted to add one to test execution failure, but there is no expectRevert cheatcode... Possibly a # TODO?

[karmacoma-eth]

looks good, thanks @luksgrin! I'll make a couple small changes to have CI pass directly to the branch if you don't mind

[luksgrin]

looks good, thanks @luksgrin! I'll make a couple small changes to have CI pass directly to the branch if you don't mind

No problem! Thanks😄

[daejunpark]

@daejunpark Please let me know if the tests I added are enough. I wanted to add one to test execution failure, but there is no expectRevert cheatcode... Possibly a # TODO?

Awesome! Currently, you can use the expected json exitcode to test the failure cases. Please feel free to add negative tests if you already have something in mind.

[luksgrin]

@daejunpark Please let me know if the tests I added are enough. I wanted to add one to test execution failure, but there is no expectRevert cheatcode... Possibly a # TODO?

Awesome! Currently, you can use the expected json exitcode to test the failure cases. Please feel free to add negative tests if you already have something in mind.

I had one but I removed it! I will write it again so that we can add it 😃

[luksgrin]

@daejunpark Please let me know if the tests I added are enough. I wanted to add one to test execution failure, but there is no expectRevert cheatcode... Possibly a # TODO?

Awesome! Currently, you can use the expected json exitcode to test the failure cases. Please feel free to add negative tests if you already have something in mind.

I had one but I removed it! I will write it again so that we can add it 😃

Done!

[daejunpark]

Thank you! Let me reorg the pytest tests to exclude the ffi tests on windows.

[daejunpark]

@luksgrin I've modified the semantics of ffi so that it does not fail (but generates an warning) when stderr is present, in order to align with Foundry's behavior: 57241d8

Please let me know if you have a concern with this!

[daejunpark]

@luksgrin let me go ahead and merge this for now, as it's been open for quite some time. we can create a separate pr if the semantics of ffi needs to be improved. thanks for your contribution!

[luksgrin]

Tysm for merging! I believe it is a perfect choice to imitate foundry's default behavior :)