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"use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.default = isISIN;
var _assertString = _interopRequireDefault(require("./util/assertString"));
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
var isin = /^[A-Z]{2}[0-9A-Z]{9}[0-9]$/; // this link details how the check digit is calculated:
// https://www.isin.org/isin-format/. it is a little bit
// odd in that it works with digits, not numbers. in order
// to make only one pass through the ISIN characters, the
// each alpha character is handled as 2 characters within
// the loop.
function isISIN(str) {
(0, _assertString.default)(str);
if (!isin.test(str)) {
return false;
}
var double = true;
var sum = 0; // convert values
for (var i = str.length - 2; i >= 0; i--) {
if (str[i] >= 'A' && str[i] <= 'Z') {
var value = str[i].charCodeAt(0) - 55;
var lo = value % 10;
var hi = Math.trunc(value / 10); // letters have two digits, so handle the low order
// and high order digits separately.
for (var _i = 0, _arr = [lo, hi]; _i < _arr.length; _i++) {
var digit = _arr[_i];
if (double) {
if (digit >= 5) {
sum += 1 + (digit - 5) * 2;
} else {
sum += digit * 2;
}
} else {
sum += digit;
}
double = !double;
}
} else {
var _digit = str[i].charCodeAt(0) - '0'.charCodeAt(0);
if (double) {
if (_digit >= 5) {
sum += 1 + (_digit - 5) * 2;
} else {
sum += _digit * 2;
}
} else {
sum += _digit;
}
double = !double;
}
}
var check = Math.trunc((sum + 9) / 10) * 10 - sum;
return +str[str.length - 1] === check;
}
module.exports = exports.default;
module.exports.default = exports.default;
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