Proper exit codes usage

[anton-trunov]

Summary

Exit codes from 0 to 127 are reserved for TVM or FunC and from 128 to 255 for Tact. Only the range from 256 to 65535 is free for developer-defined exit codes.

Context

https://docs.tact-lang.org/book/exit-codes

Examples

// Bad example that illustrates the problem
contract Foo {
    const NotOwnerExitCode: Int = 128;
    receive("foobar") {
        nativeThrowUnless(self.NotOwnerExitCode, sender() == self.owner);
    }
}

Use instead:

contract Foo {
    const NotOwnerExitCode: Int = 256; // <-- exit code from the allowed range
    receive("foobar") {
        nativeThrowUnless(self.NotOwnerExitCode, sender() == self.owner);
    }
}