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Testing String Utility Functions in 30-seconds-of-code

This test suite validates the StringUtils library’s string manipulation functions in the 30-seconds-of-code repository. It covers essential string operations including case conversion, HTML/Markdown stripping, and SEO slug generation using Jest testing framework.

Test Coverage Overview

The test suite provides comprehensive coverage of string utility functions:

Case manipulation (capitalize, kebab case)
ID and slug generation
HTML/Markdown content stripping
Text normalization and escaping
Tag formatting

Edge cases include handling of special characters, HTML entities, and mixed content types.

Implementation Analysis

The testing approach employs Jest’s describe/it blocks for clear test organization and isolation. Each utility function is tested independently using expect assertions with precise input/output validation.

The implementation leverages Jest’s toBe and toEqual matchers for strict equality checking, with well-structured test cases demonstrating function behavior.

Technical Details

Testing Framework: Jest
Test Structure: Nested describe blocks
Assertion Style: expect().toBe()
Import System: ES Modules
File Organization: Modular test suite

Best Practices Demonstrated

The test suite exemplifies several testing best practices including descriptive test cases, isolation of functionality, and comprehensive coverage of edge cases.

Clear test descriptions
Single responsibility principle
Consistent naming conventions
Modular test organization
Comprehensive function coverage

chalarangelo/30-seconds-of-code

spec/lib/stringUtils.test.js

            
import { describe, it, expect } from 'vitest';
import StringUtils from '#src/lib/stringUtils.js';

describe('StringUtils', () => {
  describe('capitalize', () => {
    it('should capitalize the first letter of a string', () => {
      expect(StringUtils.capitalize('hello')).toBe('Hello');
    });

    it('should capitalize the first letter and lowercase the rest of a string', () => {
      expect(StringUtils.capitalize('hello', true)).toBe('Hello');
    });
  });

  describe('toKebabCase', () => {
    it('should convert a string to kebab case', () => {
      expect(StringUtils.toKebabCase('Hello World')).toBe('hello-world');
    });
  });

  describe('convertToValidId', () => {
    it('should convert a string to a valid id name', () => {
      const htmlString = '<p>This is a <strong>paragraph</strong>.</p>';
      const validId = 'this-is-a-paragraph';

      expect(StringUtils.convertToValidId(htmlString)).toBe(validId);
    });
  });

  describe('convertToSeoSlug', () => {
    it('should convert a string to a SEO slug', () => {
      expect(StringUtils.convertToSeoSlug('Hello World')).toBe('/hello-world');
    });
  });

  describe('stripMarkdownFormat', () => {
    const markdownString =
      'This is `code` and this is **bold** and this is [a link](https://example.com) and this is _italic_.';
    const strippedString =
      'This is code and this is bold and this is a link and this is italic.';

    it('should strip markdown format from a string', () => {
      expect(StringUtils.stripMarkdown(markdownString)).toBe(strippedString);
    });
  });

  describe('stripHtmlParagraphsAndLinks', () => {
    it('should strip HTML paragraphs and links', () => {
      expect(
        StringUtils.stripHtmlParagraphsAndLinks(
          '<p><a href="http://example.com">Hello</a></p>'
        )
      ).toBe('Hello');
    });
  });

  describe('stripHtmlTags', () => {
    const htmlString = '<p>This is a <strong>paragraph</strong>.</p>';
    const strippedString = 'This is a paragraph.';

    it('should strip HTML tags from a string', () => {
      expect(StringUtils.stripHtmlTags(htmlString)).toBe(strippedString);
    });
  });

  describe('stripHtml', () => {
    it('should strip HTML', () => {
      expect(StringUtils.stripHtml('<p>Hello & hi!</p>')).toBe(
        'Hello & hi!'
      );
    });
  });

  describe('normalizedTokens', () => {
    it('should normalize tokens', () => {
      expect(StringUtils.normalizedTokens('Hello a World!')).toEqual([
        'hello',
        'world',
      ]);
    });
  });

  describe('escapeHtml', () => {
    it('should escape HTML', () => {
      expect(StringUtils.escapeHtml('Hello & "world"')).toBe(
        'Hello & "world"'
      );
    });
  });

  describe('formatTag', () => {
    it('should format a tag', () => {
      expect(StringUtils.formatTag('hello')).toBe('Hello');
    });
  });
});