convert hex to decimal with native bigint

Author: rolodato

flagsmith-engine/utils/hashing/index.ts

@@ -6,31 +6,6 @@ const makeRepeated = (arr: Array<any>, repeats: number) =>
     Array.from({ length: repeats }, () => arr).flat();
 
 // https://stackoverflow.com/questions/12532871/how-to-convert-a-very-large-hex-number-to-decimal-in-javascript
-function h2d(s: string): string {
-    function add(x: string, y: string) {
-        var c = 0,
-            r: number[] = [];
-        const a  = x.split('').map(Number);
-        const b = y.split('').map(Number);
-        while (x.length || y.length) {
-            var s = (a.pop() || 0) + (b.pop() || 0) + c;
-            r.unshift(s < 10 ? s : s - 10);
-            c = s < 10 ? 0 : 1;
-        }
-        if (c) r.unshift(c);
-        return r.join('');
-    }
-
-    var dec = '0';
-    s.split('').forEach(function (chr: any) {
-        var n = parseInt(chr, 16);
-        for (var t = 8; t; t >>= 1) {
-            dec = add(dec, dec);
-            if (n & t) dec = add(dec, '1');
-        }
-    });
-    return dec;
-}
 /**
  * Given a list of object ids, get a floating point number between 0 and 1 based on
  * the hash of those ids. This should give the same value every time for any list of ids.
@@ -42,12 +17,12 @@ function h2d(s: string): string {
 export function getHashedPercentateForObjIds(objectIds: Array<any>, iterations = 1): number {
     let toHash = makeRepeated(objectIds, iterations).join(',');
     const hashedValue = md5(toHash);
-    const hashedInt = BigInt(h2d(hashedValue));
-    const value = (((hashedInt) % 9999n) / 9998n) * 100n;
+    const hashedInt = BigInt('0x' + hashedValue);
+    const value = (Number((hashedInt % 9999n)) / 9998.0) * 100;
 
     // we ignore this for it's nearly impossible use case to catch
     /* istanbul ignore next */
-    if (value === 100n) {
+    if (value === 100) {
         /* istanbul ignore next */
         return getHashedPercentateForObjIds(objectIds, iterations + 1);
     }