text: const classListBuilder = require("./index");
  
  describe("classListBuilder", () => {
    const arg1 = "arg1",
      arg2 = "arg2";
  
    it("When passed a single argument, returns a string with no trailing space", () => {
      expect(classListBuilder(arg1)).toMatch(arg1);
    });
  
    it("When passed multiple arguments, returns a string of arguments", () => {
      expect(classListBuilder(arg1, arg2)).toMatch(`${arg1} ${arg2}`);
    });
  
    it("When passed an undefined argument, returns a string without said argument", () => {
      expect(classListBuilder(arg1, undefined, arg2)).toMatch(`${arg1} ${arg2}`);
    });
  
    it("When passed an argument that evaluates to `false`, returns a string without said argument", () => {
      expect(classListBuilder(arg1, 0, arg2)).toMatch(`${arg1} ${arg2}`);
    });
  });
  