Bit-Wasp / bitcoin-php

src/Amount.php

<?php

declare(strict_types=1);

namespace BitWasp\Bitcoin;

class Amount
{
    const COIN = 100000000;

    /**
     * @param int $satoshis
     * @return string
     */
    public function toBtc(int $satoshis): string
    {
        return bcdiv((string)$satoshis, (string) self::COIN, 8);

The expression return bcdiv((string)$satoshis, (string)self::COIN, 8) could return the type null which is incompatible with the type-hinted return string. Consider adding an additional type-check to rule them out.

    }

    /**
     * @param string $btcAmount
     * @return int
     */
    public function toSatoshis(string $btcAmount): int
    {
        return (int) bcmul($btcAmount, (string) self::COIN, 0);
    }
}