isogram.spec.js

import { isIsogram } from './isogram';

describe('Isogram Test Suite', () => {
  test('empty string', () => {
    expect(isIsogram('')).toEqual(true);
  });

  test('isogram with only lower case characters', () => {
    expect(isIsogram('isogram')).toEqual(true);
  });

  test('word with one duplicated character', () => {
    expect(isIsogram('eleven')).toEqual(false);
  });

  test('word with one duplicated character from the end of the alphabet', () => {
    expect(isIsogram('zzyzx')).toEqual(false);
  });

  test('longest reported english isogram', () => {
    expect(isIsogram('subdermatoglyphic')).toEqual(true);
  });

  test('word with duplicated character in mixed case', () => {
    expect(isIsogram('Alphabet')).toEqual(false);
  });

  test('word with duplicated character in mixed case, lowercase first', () => {
    expect(isIsogram('alphAbet')).toEqual(false);
  });

  test('hypothetical isogrammic word with hyphen', () => {
    expect(isIsogram('thumbscrew-japingly')).toEqual(true);
  });

  test('isogram with duplicated hyphen', () => {
    expect(isIsogram('six-year-old')).toEqual(true);
  });

  test('made-up name that is an isogram', () => {
    expect(isIsogram('Emily Jung Schwartzkopf')).toEqual(true);
  });

  test('duplicated character in the middle', () => {
    expect(isIsogram('accentor')).toEqual(false);
  });

  test('same first and last characters', () => {
    expect(isIsogram('angola')).toEqual(false);
  });
});