Truffle-migtration-4.x/Validation of nested tuples doesn't work properly in contract's methods

[nikoulai]

In the truffle project, in some of their tests, they pass in a method of a contract a nested tuple as an argument.

let result = await deployedContract.run([[7, -5], 3], 1, address, address);

However, during the migration to 4.x I noticed that the validation fails with the error:

    Web3 validator found 3 error[s]:
    value "7,-5" at "/0/1" must pass "uint256" validation
    value "7,-5,3" at "/1" must pass "uint8" validation
    value "1" at "/2" must pass "address" validation
   

which indicates that our library doesn't parse right the arguments.

This happens in two tests (however, they use the same call):

https://github.com/nazarhussain/truffle/blob/20b70910c79683cdb4b4d983e95b05476fed165c/packages/decoder/test/current/test/downgrade-test.js#L83

https://github.com/nazarhussain/truffle/blob/20b70910c79683cdb4b4d983e95b05476fed165c/packages/decoder/test/current/test/downgrade-test.js#L103