Add a simple wrapper for address.

[Skyge]

Fix #1771.

[Skyge]

It seems like I should also add test example at test/utils/Address.test.js.

[nventuro]

Hello @Skyge, thank you for this contribution!

Yes, we should add this in AddresMock to test it, and have tests that:

1. convert the zero address
2. convert some random address
3. convert an address of all ones (0xffff...)

All three tests should check that the input address matches the output.

[Skyge]

Hi, @nventuro , do you mean mocks/AddressImpl.sol? because I did not fine a file named AddresMock .

[nventuro]

Yes, my bad. Some of the mocks are inconsistently named.

[Skyge]

@nventuro Hi, I have thought for the test case for some time, so my process will be like this: First I need a simple contract which can receive Ether, then I use an account to call a function mainly including address(A).transfer(100), because the account is not the type of payable, it will throw out an error message, then if I call another function mainly including address(A).toPayable().transfer(100), it will pass, and the balance of account A should add 100.
Same approach for testing the address(0) and address(0xffff...), so what do you think about it? Or I should take another approach to test?

[nventuro]

I don't think you'll need to do any of that, because the payable attribute is only something the compiler uses to make developers aware of which addresses may receive funds, it's not a property of the address itself.

A function that receives an address, calls toPayable() on it and returns it, and checks that the sent and received addresses are the same should be enough.

[Skyge]

Emmm, but if I send an address to such a function, it returns an address, how can I know it is a really address payable?

[Skyge]

@nventuro I notice there is a constant in the openzeppelin-test-helpers: ZERO_ADDRESS, it is convenient for us to quote, but just like your advice, I also should test for the address of all ones, so is there a necessary to add such constant in the openzeppelin-test-helpers, and what should I name it better?

[nventuro]

Emmm, but if I send an address to such a function, it returns an address, how can I know it is a really address payable?

payable is a compile-time attribute. The fact that the returned type is payable and the contract compiles is enough: all we need to actually test this function is to check that the actual value (the address) is not being accidentally modified.

I also should test for the address of all ones, so is there a necessary to add such constant in the openzeppelin-test-helpers, and what should I name it better?

I don't think this is necessary, since using this address is very uncommon: I'd just use the '0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF' string directly.

[Skyge]

I don't think this is necessary, since using this address is very uncommon: I'd just use the '0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF' string directly.

You can see at the line 7, I define a constant: ALL_ONES_ADDRESS = '0xFFfFfFffFFfffFFfFFfFFFFFffFFFffffFfFFFfF', it is neither 0xffffffffffffffffffffffffffffffffffffffff,nor 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF.

[nventuro]

Great work @Skyge, thank you very much for your contribution! 🎉

[Skyge]

It is my pleasure!