Support circular dependencies

[rkalis]

Several people reported issues with circular dependencies on truffle-plugin-verify (#14, #17). It appears that sol-merger gets stuck in an infinite loop and runs out of memory eventually. @nklipa13 added a very small example that shows this in truffle-plugin-verify#14. I believe @ferittuncer also has more complex contract examples.

[rkalis]

It looks like it might still not completely work (at least for the repository I tested it with - ethroulette).

Steps to reproduce:

git clone [email protected]:rkalis/ethroulette.git && cd ethroulette
npm i -g [email protected]
sol-merger "./contract/Roulette.sol"

It then gets stuck.

The repo has a UML diagram of the structure of the Roulette contracts, but basically BackingContract and BackedToken depend on each other, and Roulette extends BackingContract.

[RyuuGan]

@rkalis I found the issue and it is not about circular dependencies, so I'll fix it asap.

[rkalis]

Oh awesome! Thanks for looking into it. I'd just assumed it was due to circular dependencies. Thanks for fixing the issues!