From 155dd49434d5bca144a9ab338f0bb7ef7a6ec8b7 Mon Sep 17 00:00:00 2001
From: Coffee Converter <coffee.becomes.code@gmail.com>
Date: Tue, 24 Mar 2020 15:53:31 -0500
Subject: [PATCH] slightly improves performance in randBits()

 - only calculates (bitLength % 8) once
 - uses const where possible
---
 src/main.js | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/main.js b/src/main.js
index 795a953..f3c8656 100644
--- a/src/main.js
+++ b/src/main.js
@@ -400,13 +400,14 @@ export function randBits(bitLength, forceLength = false) {
         throw new RangeError(`bitLength MUST be > 0 and it is ${bitLength}`);
 
     const byteLength = Math.ceil(bitLength / 8);
-    let rndBytes = randBytesSync(byteLength, false);
-    if (bitLength % 8) {
+    const rndBytes = randBytesSync(byteLength, false);
+    const bitLengthMod8 = bitLength % 8;
+    if (bitLengthMod8) {
         // Fill with 0's the extra bits
-        rndBytes[0] = rndBytes[0] & (2 ** (bitLength % 8) - 1);
+        rndBytes[0] = rndBytes[0] & (2 ** bitLengthMod8 - 1);
     }
     if (forceLength) {
-        let mask = (bitLength % 8) ? 2 ** ((bitLength % 8) - 1) : 128;
+        const mask = bitLengthMod8 ? 2 ** (bitLengthMod8 - 1) : 128;
         rndBytes[0] = rndBytes[0] | mask;
     }
     return rndBytes;