Commit

1 files changed, 51 insertions, 0 deletions

diff --git a/src/node_modules/validator/es/lib/isISBN.js b/src/node_modules/validator/es/lib/isISBN.js
new file mode 100644
index 0000000..da2c435
--- /dev/null
+++ b/src/node_modules/validator/es/lib/isISBN.js
@@ -0,0 +1,51 @@
+import assertString from './util/assertString';
+var isbn10Maybe = /^(?:[0-9]{9}X|[0-9]{10})$/;
+var isbn13Maybe = /^(?:[0-9]{13})$/;
+var factor = [1, 3];
+export default function isISBN(str) {
+  var version = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : '';
+  assertString(str);
+  version = String(version);
+
+  if (!version) {
+    return isISBN(str, 10) || isISBN(str, 13);
+  }
+
+  var sanitized = str.replace(/[\s-]+/g, '');
+  var checksum = 0;
+  var i;
+
+  if (version === '10') {
+    if (!isbn10Maybe.test(sanitized)) {
+      return false;
+    }
+
+    for (i = 0; i < 9; i++) {
+      checksum += (i + 1) * sanitized.charAt(i);
+    }
+
+    if (sanitized.charAt(9) === 'X') {
+      checksum += 10 * 10;
+    } else {
+      checksum += 10 * sanitized.charAt(9);
+    }
+
+    if (checksum % 11 === 0) {
+      return !!sanitized;
+    }
+  } else if (version === '13') {
+    if (!isbn13Maybe.test(sanitized)) {
+      return false;
+    }
+
+    for (i = 0; i < 12; i++) {
+      checksum += factor[i % 2] * sanitized.charAt(i);
+    }
+
+    if (sanitized.charAt(12) - (10 - checksum % 10) % 10 === 0) {
+      return !!sanitized;
+    }
+  }
+
+  return false;
+}
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