text: const expect = require('chai').expect;
  const Quirk = require("../../index");
  
  describe('add substitutions', function () {
      it('should create a valid quirk from substitutions added via addSubstitution', function () {
          let testSub = new Quirk();
          testSub.addSubstitution('w', 'ww');
          testSub.addSubstitution('v', 'vv');
          expect(testSub.toPlain("wweh evveryone is mean")).to.equal('weh everyone is mean');
          expect(testSub.toQuirk("weh everyone is mean")).to.equal('wweh evveryone is mean');
      });
  
      it('should create a valid case-insensitive quirk from substitutions added via addSubstitution', function () {
          let testSub = new Quirk();
          testSub.addSubstitution('i', 'ii', {ignoreCase: true});
          testSub.addSubstitution('s', '2', {ignoreCase: true});
          expect(testSub.toPlain("thii2 ii2 bee e22!")).to.equal('This is bee ess!');
          expect(testSub.toQuirk("this IS BEE ESS!")).to.equal('thii2 ii2 BEE E22!');
      });
  
  
      it('should throw an error when given an invalid substitution to add', function () {
          const badFn = () => {
              let testSub = new Quirk();
              testSub.addSubstitution('w');
          }
          expect(badFn).to.throw();
      });
  
  });
  