fix: improve error message for conflicting methods IDs

[trocher]

What I did

Fix #3133

How I did it

I modified collision_str in validate_unique_method_ids so that we look for the collision ID in lists of IDs instead of looking for it in lists of function signature

How to verify it

Trying to compile the following contract will now output the name of the functions having a collision:

@external
def OwnerTransferV7b711143(a : uint256) : 
    pass
@external
def withdraw(a : uint256):
    pass

Commit message

fix: improve error message for conflicting methods IDs

Description for the changelog

Improve error message for conflicting methods IDs

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[codecov-commenter]

Codecov Report

Merging #3134 (39d4c55) into master (b13595f) will decrease coverage by 0.10%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #3134      +/-   ##
==========================================
- Coverage   88.49%   88.39%   -0.11%     
==========================================
  Files          95       95              
  Lines       10760    10761       +1     
  Branches     2266     2266              
==========================================
- Hits         9522     9512      -10     
- Misses        796      806      +10     
- Partials      442      443       +1     

Impacted Files	Coverage Δ
vyper/semantics/validation/utils.py	91.80% <100.00%> (+0.03%)	⬆️
vyper/codegen/arithmetic.py	79.48% <0.00%> (-5.13%)	⬇️
vyper/ast/nodes.py	93.05% <0.00%> (-0.17%)	⬇️
vyper/builtin_functions/functions.py	90.37% <0.00%> (-0.17%)	⬇️

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[charles-cooper]

interesting -- i think we should output the full function signatures (including the arguments), and also the colliding method id. ex.

Methods produce colliding method ID `0x2e1a7d4d`: OwnerTransferV7b711143(uint256), withdraw(uint256)

[trocher]

Made the changes you mentioned, one can verify that functions with default arguments are handled correctly with the following contract:

@external
def OwnerTransferV7b711143(a: uint256) : 
    pass
@external
def withdraw(a: uint256, b: uint256 = 0):
    pass
@external
def foo(a: uint256):
    pass

[charles-cooper]

hex(collision) might produce a badly formatted method ID if collision requires fewer than 4 bytes (e.g. collision == 1).

[charles-cooper]

awesome, nice work. thanks!

[trocher]

Forgot to run mypy, sorry for that!