Fix canColonyMintNativeToken resover to work with all tokens

[rdig]

The current implementation of this resolver assumes that all tokens have the authority() function built in their contract, but this is rather of our doing, so only Colony Contract created tokens do have it. Others might not (most likely will not)

Due to this, if a colony will have been created using an external token (in this case the actual metacolony), the dapp will actually crash as we don't handle this case.

Even worse, tokens might be able to be minted, even if they don't have the authority method, as the mint function is somewhat standard on most, and the user creating the colony might actually be the owner of said token, so we need to check for that as well.

For this I've chosen to go the "estimate route", by estimating gas on the call to mint, and if it succeeds assume the user can mint, and if it fails, they can't.

This approach should cover most cases

Testing

This is quite tricky to test (it's actually easier on QA), but I'll try to do my best to explain how to.

1. Start the truffle console

Inside the src/lib/colonyNetwork folder, run yarn truffle console (or ./node_modules/.bin/truffle console)

2. Deploy a new "non-standard" token. We'll use ERC20PresetMinterPauser since it's available to us already.

Inside the truffle console, run:

tk = await ERC20PresetMinterPauser.new("Token Name", "TKN")

then

tk.address

3. Create a new colony via the Dapp and use the above address as an external token (don't create a new token)

Once created, if the colony loads, and doesn't show the "Mint" and "Unlock" menu entries in the "Actions" menu, then this fix worked.

Changes

• canColonyMintNativeToken resolver in the colony resolvers file

[arrenv]

@rdig I like the approach, I will have to remember this one. It is working well for me.

Tested with newly created token:

Tested with existing token and permission:

Test with existing token and no permission

Test with existing token and no permission and Motions & Disputes extension

[chinins]

I like this approach too!

[ArmandoGraterol]

Didn't know that you could also do this to check if the colony can mint! TIL