als-statistics/tests/descriptive/weighted-mean.test.js

Modular JS statistics toolkit for Node.js and the browser: descriptive stats, correlations (Pearson/Spearman/Kendall), t-tests & ANOVA (Student/Welch), reliability (Cronbach’s alpha), regression (linear/logistic), clustering (DBSCAN/HDBSCAN), and table/co

import { describe, it } from 'node:test';
import assert from 'node:assert';
import weightedMean from '../../lib/descriptive/weighted-mean.js';

describe('weightedMean function', () => {
   it('should compute weighted mean correctly', () => {
      const values = [10, 20, 30];
      const weights = [1, 2, 3];
      assert.strictEqual(weightedMean(weights, values).toFixed(2), '23.33');
   });

   it('should return 0 when weights sum to 0', () => {
      const values = [10, 20, 30];
      const weights = [0, 0, 0];
      assert.strictEqual(weightedMean(weights, values), 0);
   });

   it('should throw error for mismatched lengths', () => {
      const values = [10, 20, 30];
      const weights = [1, 2];
      assert.throws(() => weightedMean(weights, values), /Weights must be an array of the same length as values/);
   });
});