Merge pull request #120 from darrelfrancis/master

Resolve #81 to deal with a potential future scenario of PRNG generating `1`

Author: perry-mitchell

source/utils.ts

@@ -2,11 +2,11 @@ import { ENCODING, ENCODING_LEN } from "./constants.js";
 import { PRNG } from "./types.js";
 
 export function randomChar(prng: PRNG): string {
-    let rand = Math.floor(prng() * ENCODING_LEN);
-    if (rand === ENCODING_LEN) {
-        rand = ENCODING_LEN - 1;
-    }
-    return ENCODING.charAt(rand);
+    // Currently PRNGs generate fractions from 0 to _less than_ 1, so no "%" is necessary.
+    // However, just in case a future PRNG can generate 1, 
+    // we are applying "% ENCODING LEN" to wrap back to the first character
+    const randomPosition = Math.floor(prng() * ENCODING_LEN) % ENCODING_LEN; 
+    return ENCODING.charAt(randomPosition);
 }
 
 export function replaceCharAt(str: string, index: number, char: string): string {