eslint-plugin-sonarjs
Version:
SonarJS rules for ESLint
34 lines (33 loc) • 1.22 kB
JavaScript
;
/*
* SonarQube JavaScript Plugin
* Copyright (C) 2011-2025 SonarSource Sàrl
* mailto:info AT sonarsource DOT com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the Sonar Source-Available License Version 1, as published by SonarSource SA.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the Sonar Source-Available License for more details.
*
* You should have received a copy of the Sonar Source-Available License
* along with this program; if not, see https://sonarsource.com/license/ssal/
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.shannonEntropy = shannonEntropy;
function shannonEntropy(str) {
if (!str) {
return 0;
}
const len = str.length;
const occurrences = {};
for (const ch of str) {
occurrences[ch] = (occurrences[ch] ?? 0) + 1;
}
return (Object.values(occurrences)
.map(count => count / len)
.map(freq => -freq * Math.log(freq))
.reduce((acc, e) => acc + e, 0) / Math.log(2));
}