better.js

class Student {
  constructor (student) {
    this.student = student;
  }
  
  map(f) {
    const student = Object.assign({}, this.student);
    return new Student(f(student))
  }
  
  take(item) {
    const student = Object.assign({}, this.student);
    student.items.push(item);
    return new Student(student);
  }
  
  giveHomework(homeworkQuantity) {
    const student = Object.assign({}, this.student);
    student.homeworkQuantity += homeworkQuantity;
    return new Student(student);
  }
  
  doHomework() {
    const student = Object.assign({}, this.student);
    const doneHomework = student.items.reduce((done, item) => {
      if(item === 'pencil') {
        student.homeworkQuantity -= 1;
        return true;
      }
      return doneHomework;
    }, false);
    
    if(!doneHomework) {
      console.log('Missing pencil to do homework');
    }
    
    return new Student(student);
  }
  
  logMyState() {
    console.log(this.student);
    return new Student(this.student);
  }
  
  static newStudent(name) {
    return new Student({
      name,
      items: [],
      homeworkQuantity: 0,
    });
  }
}

const student = Student.newStudent('Josh');

student
  .logMyState()
  .giveHomework(2)
  .doHomework() // "Missing pencil to do homework"
  .take('ruler')
  .take('coffee')
  .logMyState()
  .doHomework() // "Missing pencil to do homework"
  .take('pencil')
  .doHomework()
  .doHomework()
  .logMyState()
  .map(student => Object.assign({}, student, { homeworkQuantity: 'rebel' }))
  .logMyState();