Check balance before doing `IERC20.transferFrom`

[dhruvkelawala]

Problem

https://github.com/starknet-id/naming_contract/blob/8d7f4b7a06b895df1d612e9ae739d09502e1dd80/src/naming/registration.cairo#L60

Here, you execute transferFrom on ERC20 without checking for balance. So if the balance is not enough, it throws error on wallets when estimateFee is called by the wallets. OZ's ERC20 contracts doesn't show errors properly. So it becomes very difficult for the wallets to handle it and users to know what the actual error is.

This is what the error looks like:

Error in the called contract (0x6ac597f8116f886fa1c97a23fa4e08299975ecaf6b598873ca6792b9bbfb678):
Error at pc=0:15:
Got an exception while executing a hint.
Cairo traceback (most recent call last):
Unknown location (pc=0:214)
Unknown location (pc=0:200)

Error in the called contract (0x6ac597f8116f886fa1c97a23fa4e08299975ecaf6b598873ca6792b9bbfb678):
Error at pc=0:178:
Got an exception while executing a hint.
Cairo traceback (most recent call last):
Unknown location (pc=0:2822)
Unknown location (pc=0:2800)
Unknown location (pc=0:1712)
Unknown location (pc=0:1380)

Error in the called contract (0x49d36570d4e46f48e99674bd3fcc84644ddd6b96f7c741b1562b82f9e004dc7):
Error at pc=0:104:
Got an exception while executing a hint.
Cairo traceback (most recent call last):
Unknown location (pc=0:1678)
Unknown location (pc=0:1664)

Error in the called contract (0x49d36570d4e46f48e99674bd3fcc84644ddd6b96f7c741b1562b82f9e004dc7):
Error at pc=0:9:
Got an exception while executing a hint.
Cairo traceback (most recent call last):
Unknown location (pc=0:1434)
Unknown location (pc=0:1395)
Unknown location (pc=0:915)

Traceback (most recent call last):
  File "<hint1>", line 3, in <module>
AssertionError: assert_not_zero failed: 0 = 0.

Possible Solution

I would suggest to check for balance before doing this transferFrom and use an assert statement with with_attr error_message to display correct message.