Improve DevEx when `env().transfer` fails due to `DecimalPrecisionLoss`

[AlexD10S]

While working with a simple ink! contract that uses env().transfer, I ran into an unexpected error when using small transfer values like 1 or 10:

Contract Reverted! "DecimalPrecisionLoss"   "Failed to convert an EVM balance to a native balance."

Minimal Example

#[ink(message)]
pub fn transfer(&mut self, to: H160, value: U256) {
    self.env().transfer(to, value);
}

Calling this method with value = 1 or 10 triggers the revert, while using a larger amount (e.g., 1_000_000) works fine.

The issue seems to stem from a mismatch between the EVM 18 decimal format (U256) and the Substrate-based chain’s native balance (Tested with ink-node). Smaller values are likely too low to be accurately converted, triggering a DecimalPrecisionLoss error.

DevEx concern

This error is not obvious to developers, especially when testing or writing basic contract logic. How can we improve the DevEx of this?