import { expect, test, describe } from "vitest";
import { SimilarityCalculator } from "../../src/utils/similarity.js";
describe('SimilarityCalculator', () => {
describe('calculateSimilarityScore', () => {
test('should return 1.0 for identical strings', () => {
expect(SimilarityCalculator.calculateSimilarityScore('lodash', 'lodash')).toBe(1.0);
expect(SimilarityCalculator.calculateSimilarityScore('test', 'test')).toBe(1.0);
expect(SimilarityCalculator.calculateSimilarityScore('', '')).toBe(1.0);
});
test('should return 0.9 for substring matches', () => {
expect(SimilarityCalculator.calculateSimilarityScore('lodash', 'lodash-es')).toBe(0.9);
expect(SimilarityCalculator.calculateSimilarityScore('react', 'react-dom')).toBe(0.9);
expect(SimilarityCalculator.calculateSimilarityScore('express', 'express-session')).toBe(0.9);
});
test('should return 0.9 for reverse substring matches', () => {
expect(SimilarityCalculator.calculateSimilarityScore('lodash-es', 'lodash')).toBe(0.9);
expect(SimilarityCalculator.calculateSimilarityScore('react-dom', 'react')).toBe(0.9);
expect(SimilarityCalculator.calculateSimilarityScore('express-session', 'express')).toBe(0.9);
});
test('should be case insensitive', () => {
expect(SimilarityCalculator.calculateSimilarityScore('LODASH', 'lodash')).toBe(1.0);
expect(SimilarityCalculator.calculateSimilarityScore('React', 'REACT-DOM')).toBe(0.9);
expect(SimilarityCalculator.calculateSimilarityScore('Express', 'express')).toBe(1.0);
});
test('should calculate similarity for similar strings', () => {
// Single character difference
const score1 = SimilarityCalculator.calculateSimilarityScore('lodash', 'lodas');
expect(score1).toBeCloseTo(0.833, 2); // 1 - (1/6)
// Two character difference
const score2 = SimilarityCalculator.calculateSimilarityScore('express', 'expres');
expect(score2).toBeCloseTo(0.857, 2); // 1 - (1/7)
});
test('should handle completely different strings', () => {
const score = SimilarityCalculator.calculateSimilarityScore('lodash', 'django');
expect(score).toBeLessThan(0.5);
expect(score).toBeGreaterThanOrEqual(0);
});
test('should handle empty strings', () => {
expect(SimilarityCalculator.calculateSimilarityScore('', 'test')).toBe(0);
expect(SimilarityCalculator.calculateSimilarityScore('test', '')).toBe(0);
expect(SimilarityCalculator.calculateSimilarityScore('', '')).toBe(1.0);
});
test('should handle strings of very different lengths', () => {
const score = SimilarityCalculator.calculateSimilarityScore('a', 'verylongstring');
expect(score).toBeLessThan(0.5);
expect(score).toBeGreaterThanOrEqual(0);
});
test('should handle special characters and numbers', () => {
expect(SimilarityCalculator.calculateSimilarityScore('@types/node', '@types/react')).toBeGreaterThan(0.5);
expect(SimilarityCalculator.calculateSimilarityScore('package-1.0', 'package-2.0')).toBeGreaterThan(0.8);
expect(SimilarityCalculator.calculateSimilarityScore('my_package', 'my-package')).toBeGreaterThan(0.8);
});
test('should provide symmetric results', () => {
const pairs = [
['lodash', 'lodash-es'],
['react', 'preact'],
['express', 'koa'],
['test', 'jest']
];
for (const [str1, str2] of pairs) {
const score1 = SimilarityCalculator.calculateSimilarityScore(str1, str2);
const score2 = SimilarityCalculator.calculateSimilarityScore(str2, str1);
expect(score1).toBe(score2);
}
});
test('should handle unicode characters', () => {
expect(SimilarityCalculator.calculateSimilarityScore('café', 'cafe')).toBeGreaterThan(0.7);
expect(SimilarityCalculator.calculateSimilarityScore('naïve', 'naive')).toBeGreaterThan(0.7);
});
test('should rank similar packages correctly', () => {
const original = 'lodash';
const candidates = ['lodash-es', 'lodash.merge', 'underscore', 'ramda', 'django'];
const scores = candidates.map(candidate => ({
name: candidate,
score: SimilarityCalculator.calculateSimilarityScore(original, candidate)
}));
scores.sort((a, b) => b.score - a.score);
// lodash-es and lodash.merge should be most similar
expect(scores[0].name).toBe('lodash-es');
expect(scores[1].name).toBe('lodash.merge');
expect(scores[0].score).toBe(0.9);
expect(scores[1].score).toBe(0.9);
// django should be least similar
expect(scores[scores.length - 1].name).toBe('django');
expect(scores[scores.length - 1].score).toBeLessThan(0.5);
});
test('should handle real-world package name examples', () => {
const testCases = [
// NPM packages
{ original: 'react', candidate: 'react-dom', expectedMin: 0.8 },
{ original: 'lodash', candidate: 'lodash-es', expectedMin: 0.8 },
{ original: 'express', candidate: 'express-session', expectedMin: 0.8 },
// Python packages
{ original: 'django', candidate: 'django-rest-framework', expectedMin: 0.7 },
{ original: 'requests', candidate: 'requests-oauthlib', expectedMin: 0.7 },
// Different ecosystems
{ original: 'react', candidate: 'vue', expectedMax: 0.4 },
{ original: 'lodash', candidate: 'ramda', expectedMax: 0.4 },
{ original: 'express', candidate: 'koa', expectedMax: 0.4 }
];
for (const { original, candidate, expectedMin, expectedMax } of testCases) {
const score = SimilarityCalculator.calculateSimilarityScore(original, candidate);
if (expectedMin) {
expect(score).toBeGreaterThanOrEqual(expectedMin);
}
if (expectedMax) {
expect(score).toBeLessThanOrEqual(expectedMax);
}
}
});
});
describe('edge cases and boundary conditions', () => {
test('should handle very long strings efficiently', () => {
const longString1 = 'a'.repeat(1000);
const longString2 = 'b'.repeat(1000);
const startTime = Date.now();
const score = SimilarityCalculator.calculateSimilarityScore(longString1, longString2);
const endTime = Date.now();
expect(score).toBe(0); // Completely different
expect(endTime - startTime).toBeLessThan(1000); // Should complete within 1 second
});
test('should handle single character strings', () => {
expect(SimilarityCalculator.calculateSimilarityScore('a', 'a')).toBe(1.0);
expect(SimilarityCalculator.calculateSimilarityScore('a', 'b')).toBe(0);
expect(SimilarityCalculator.calculateSimilarityScore('x', 'y')).toBe(0);
});
test('should handle whitespace and special characters', () => {
expect(SimilarityCalculator.calculateSimilarityScore('test package', 'test-package')).toBeGreaterThan(0.8);
expect(SimilarityCalculator.calculateSimilarityScore('my_lib', 'my-lib')).toBeGreaterThan(0.8);
expect(SimilarityCalculator.calculateSimilarityScore('package.name', 'package-name')).toBeGreaterThan(0.8);
});
test('should be deterministic', () => {
const pairs = [
['lodash', 'lodash-es'],
['react', 'preact'],
['test', 'jest']
];
for (const [str1, str2] of pairs) {
const score1 = SimilarityCalculator.calculateSimilarityScore(str1, str2);
const score2 = SimilarityCalculator.calculateSimilarityScore(str1, str2);
const score3 = SimilarityCalculator.calculateSimilarityScore(str1, str2);
expect(score1).toBe(score2);
expect(score2).toBe(score3);
}
});
});
});
