Linked List Find By Position Tests

linked-list.js

/* eslint-env node, mocha */
const { expect } = require('chai')
const LinkedList = require('../src/linked-list');

describe('Linked List', () => {
  it('Creates empty Linked Lists',  () => {
    const list = new LinkedList();
    expect(list).to.be.instanceOf(LinkedList);
    expect(list.head).to.be.null;
  });
  it('Pushes the first item properly', () => {
    const list = new LinkedList();
    list.push('A');
    expect(list.head.value).to.equal('A');
  });
  it('Gets the last item if it has one node', () => {
    const list = new LinkedList();
    list.push('A');
    expect(list.tail().value).to.equal('A');
  });
  it('Gets the last item even if empty', () => {
    const list = new LinkedList();
    expect(list.tail()).to.be.null;
  });
  it('Pushes the second item properly', () => {
    const list = new LinkedList();
    list.push('A');
    list.push('B');
    expect(list.head.next.value).to.equal('B');
  });
  it('Gets the last item if it has more than one node', () => {
    const list = new LinkedList();
    list.push('A');
    list.push('B');
    expect(list.tail().value).to.equal('B');
  });
});

describe('Linked List positions', () => {
  it('Finds existing elements by position', () => {
    const list = new LinkedList();
    list.push('A');
    list.push('B');
    list.push('C');
    expect(list.findByPosition(0).value).to.equal('A');
    expect(list.findByPosition(1).value).to.equal('B');
    expect(list.findByPosition(2).value).to.equal('C');
  });
  it('Throws error if position is smaller than zero', () => {
    const list = new LinkedList();
    expect(() => list.findByPosition(-1)).to.throw("Position must be greater than 0.");
  });
  it('Throws error if LL is shorter than position', () => {
    const list = new LinkedList();
    list.push('A');
    list.push('B');
    list.push('C');
    expect(() => list.findByPosition(3)).to.throw("Position 3 does not exist.");
  });
});

describe('Linked List positions', () => {
  it('Swaps elements by their positions', () => {
    const list = new LinkedList();
    list.push('A');
    list.push('B');
    list.push('C');
    list.swapPositions(0, 2);
    expect(list.findByPosition(0).value).to.equal('C');
    expect(list.findByPosition(1).value).to.equal('B');
    expect(list.findByPosition(2).value).to.equal('A');
  });
  it('Swaps elements by their positions', () => {
  });
});