Overtrue\Validation\Validator::getMessage PHP Method

    protected function getMessage($attribute, $rule)
    {
        $lowerRule = snake_case($rule);
        $inlineMessage = $this->getInlineMessage($attribute, $lowerRule);
        // First we will retrieve the custom message for the validation rule if one
        // exists. If a custom validation message is being used we'll return the
        // custom message, otherwise we'll keep searching for a valid message.
        if (!is_null($inlineMessage)) {
            return $inlineMessage;
        }
        $customKey = "validation.custom.{$attribute}.{$lowerRule}";
        $customMessage = $this->translator->trans($customKey);
        // First we check for a custom defined validation message for the attribute
        // and rule. This allows the developer to specify specific messages for
        // only some attributes and rules that need to get specially formed.
        if ($customMessage !== $customKey) {
            return $customMessage;
        } elseif (in_array($rule, $this->sizeRules, true)) {
            return $this->getSizeMessage($attribute, $rule);
        }
        // Finally, if no developer specified messages have been set, and no other
        // special messages apply for this rule, we will just pull the default
        // messages out of the translator service for this validation rule.
        $key = "validation.{$lowerRule}";
        if ($key !== ($value = $this->translator->trans($key))) {
            return $value;
        }
        return $this->getInlineMessage($attribute, $lowerRule, $this->fallbackMessages) ?: $key;
    }