old_contents: const {assert} = require('chai');
  const Token = require('../../src/lexer/Token');
  
  describe('Lexer::Token', () => {
    it('Should properly create a Token instance', () => {
      const token = new Token(Token.INTEGER, '2');
  
      assert.instanceOf(token, Token);
    });
  
    it('Should properly return a type of a token', () => {
      const token = new Token(Token.INTEGER, '2');
  
      assert.equal(token.getType(), 'INTEGER');
    });
  
    it('Should properly return a value of a token', () => {
      const token = new Token(Token.INTEGER, '2');
  
      assert.equal(token.getValue(), '2');
    });
  
    it('Should properly convert a token into string representation', () => {
      const token = new Token(Token.INTEGER, '2');
  
      assert.equal(token.toString(), 'Token(INTEGER, 2)');
    });
  
    it('Should properly create a new token via static create method', () => {
      const token = Token.create(Token.INTEGER, '2');
  
      assert.instanceOf(token, Token);
      assert.equal(token.getType(), 'INTEGER');
      assert.equal(token.getValue(), '2');
    });
  
    it('Should properly return a token types from static getters', () => {
      assert.equal(Token.INTEGER, 'INTEGER');
      assert.equal(Token.PLUS, 'PLUS');
      assert.equal(Token.EOF, 'EOF');
    });
  });
  
new_contents: const {assert} = require('chai');
  const Token = require('../../src/lexer/Token');
  
  describe('Lexer::Token', () => {
    it('Should properly create a Token instance', () => {
      const token = new Token(Token.INTEGER, '2');
  
      assert.instanceOf(token, Token);
    });
  
    it('Should properly return a type of a token', () => {
      const token = new Token(Token.INTEGER, '2');
  
      assert.equal(token.getType(), 'INTEGER');
    });
  
    it('Should properly return a value of a token', () => {
      const token = new Token(Token.INTEGER, '2');
  
      assert.equal(token.getValue(), '2');
    });
  
    it('Should properly convert a token into string representation', () => {
      const token = new Token(Token.INTEGER, '2');
  
      assert.equal(token.toString(), 'Token(INTEGER, 2)');
    });
  
    it('Should properly create a new token via static create method', () => {
      const token = Token.create(Token.INTEGER, '2');
  
      assert.instanceOf(token, Token);
      assert.equal(token.getType(), 'INTEGER');
      assert.equal(token.getValue(), '2');
    });
  
    it('Should properly return a token types from static getters', () => {
      assert.equal(Token.INTEGER, 'INTEGER');
      assert.equal(Token.PLUS, 'PLUS');
      assert.equal(Token.MINUS, 'MINUS');
      assert.equal(Token.EOF, 'EOF');
    });
  });
  
subject: add minor test for token types