EVM error does not always throw error in Javascript

[travs]

Sometimes calling a function via method.postTransaction(..) will result in a throw in the EVM, but this is not reflected in javascript.

The way we currently diagnose EVM throws is by examining the gas usage returned by parity.js, and comparing that to the gas input to the function. If the values are equal, but state appears not to have changed, then we assume the function threw.

Is there a way to actually do a js error throw from within parity.js in this case?
Would be very useful for debugging :)

[jacogr]

EVM limitation. However one of the Metropolis HFs does have something for this. If already in Byzantium, will update, alternatively need to wait a bit longer.

[jacogr]

ethereum/EIPs#658

(Went into Byzantium)

[travs]

@jacogr Awesome :)
So does this need to be implemented in some way on js-api end, or is it implicitly supported now?
Anything I can do to lend a hand?