WP Navigator MCP

/** * Cosine Similarity Tests * * @package WP_Navigator_MCP * @since 2.7.0 */ import { describe, it, expect } from 'vitest'; import { cosineSimilarity, normalize, dotProduct, euclideanDistance, magnitude } from './cosine.js'; describe('cosineSimilarity', () => { it('returns 1 for identical vectors', () => { const a = [1, 2, 3]; const b = [1, 2, 3]; expect(cosineSimilarity(a, b)).toBeCloseTo(1, 5); }); it('returns 0 for orthogonal vectors', () => { const a = [1, 0, 0]; const b = [0, 1, 0]; expect(cosineSimilarity(a, b)).toBeCloseTo(0, 5); }); it('returns -1 for opposite vectors', () => { const a = [1, 2, 3]; const b = [-1, -2, -3]; expect(cosineSimilarity(a, b)).toBeCloseTo(-1, 5); }); it('handles vectors with different magnitudes', () => { const a = [1, 2, 3]; const b = [2, 4, 6]; // Same direction, different magnitude expect(cosineSimilarity(a, b)).toBeCloseTo(1, 5); }); it('throws error for vectors of different lengths', () => { const a = [1, 2, 3]; const b = [1, 2]; expect(() => cosineSimilarity(a, b)).toThrow('Vector length mismatch'); }); it('returns 0 for empty vectors', () => { expect(cosineSimilarity([], [])).toBe(0); }); it('returns 0 for zero vectors', () => { const a = [0, 0, 0]; const b = [1, 2, 3]; expect(cosineSimilarity(a, b)).toBe(0); }); it('works with high-dimensional vectors', () => { const dim = 384; // Same as embedding dimension const a = new Array(dim).fill(0).map((_, i) => Math.sin(i)); const b = new Array(dim).fill(0).map((_, i) => Math.sin(i + 0.1)); // Similar but not identical const similarity = cosineSimilarity(a, b); expect(similarity).toBeGreaterThan(0.9); expect(similarity).toBeLessThan(1); }); }); describe('normalize', () => { it('normalizes a vector to unit length', () => { const v = [3, 4]; // 3-4-5 triangle const normalized = normalize(v); expect(normalized[0]).toBeCloseTo(0.6, 5); expect(normalized[1]).toBeCloseTo(0.8, 5); expect(magnitude(normalized)).toBeCloseTo(1, 5); }); it('returns empty array for empty input', () => { expect(normalize([])).toEqual([]); }); it('handles zero vector', () => { const v = [0, 0, 0]; const normalized = normalize(v); expect(normalized).toEqual([0, 0, 0]); }); it('handles negative values', () => { const v = [-3, -4]; const normalized = normalize(v); expect(magnitude(normalized)).toBeCloseTo(1, 5); }); }); describe('dotProduct', () => { it('calculates dot product correctly', () => { const a = [1, 2, 3]; const b = [4, 5, 6]; // 1*4 + 2*5 + 3*6 = 4 + 10 + 18 = 32 expect(dotProduct(a, b)).toBe(32); }); it('returns 0 for orthogonal vectors', () => { const a = [1, 0]; const b = [0, 1]; expect(dotProduct(a, b)).toBe(0); }); it('throws error for vectors of different lengths', () => { expect(() => dotProduct([1], [1, 2])).toThrow('Vector length mismatch'); }); }); describe('euclideanDistance', () => { it('returns 0 for identical vectors', () => { const a = [1, 2, 3]; expect(euclideanDistance(a, a)).toBe(0); }); it('calculates distance correctly', () => { const a = [0, 0]; const b = [3, 4]; expect(euclideanDistance(a, b)).toBe(5); // 3-4-5 triangle }); it('throws error for vectors of different lengths', () => { expect(() => euclideanDistance([1], [1, 2])).toThrow('Vector length mismatch'); }); }); describe('magnitude', () => { it('calculates magnitude correctly', () => { expect(magnitude([3, 4])).toBe(5); expect(magnitude([1, 0, 0])).toBe(1); expect(magnitude([0, 0, 0])).toBe(0); }); it('handles high-dimensional vectors', () => { const v = new Array(384).fill(1); expect(magnitude(v)).toBeCloseTo(Math.sqrt(384), 5); }); });