Function to Change Task Status

Part of the Introduction To TypeScript section of Coddy's JavaScript journey — lesson 47 of 73.

Challenge

Easy

You are provided with the following from the previous challenge:

The Task interface with id (number), title (string), and status (literal type)
Three task variables: firstTask, secondTask, and thirdTask
The getTaskInfo function
The addTask function
The initialTasks and updatedTasks arrays

Create a function named changeTaskStatus that takes three parameters:

taskList of type Task[] (an array of Task objects)
taskId of type number (the ID of the task to update)
newStatus of type 'todo' | 'in-progress' | 'done' (the new status for the task)

The function should:

Find the task with the matching ID in the task list
Update that task's status to the new status
Return a new array with the updated task (do not modify the original array)
If no task with the given ID is found, return the original array unchanged

Create a variable named testTasks of type Task[] containing firstTask, secondTask, and thirdTask.

Use your changeTaskStatus function to:

Change the status of task with ID 1 to 'in-progress' and store the result in progressTasks
Change the status of task with ID 2 to 'done' in progressTasks and store the result in completedTasks

Print the following outputs on separate lines:

Call getTaskInfo with the first task from testTasks and print the result
Call getTaskInfo with the first task from progressTasks and print the result
Call getTaskInfo with the second task from completedTasks and print the result
Print the status of the first task in testTasks
Print the status of the second task in completedTasks

Try it yourself

interface Task {
  id: number;
  title: string;
  status: 'todo' | 'in-progress' | 'done';
}

const firstTask: Task = {
  id: 1,
  title: "Learn TypeScript interfaces",
  status: 'todo'
};

const secondTask: Task = {
  id: 2,
  title: "Build task management app",
  status: 'in-progress'
};

const thirdTask: Task = {
  id: 3,
  title: "Write unit tests",
  status: 'done'
};

function getTaskInfo(task: Task): string {
    return `Task ${task.id}: ${task.title} - ${task.status}`;
}

function addTask(taskList: Task[], title: string): Task[] {
  const newTask: Task = {
    id: taskList.length + 1,
    title: title,
    status: 'todo'
  };
  return [...taskList, newTask];
}

const initialTasks: Task[] = [firstTask, secondTask];

const updatedTasks: Task[] = addTask(initialTasks, "Review code changes");

console.log(initialTasks.length);
console.log(updatedTasks.length);
console.log(getTaskInfo(updatedTasks[updatedTasks.length - 1]));
console.log(updatedTasks[updatedTasks.length - 1].title);
console.log(updatedTasks[updatedTasks.length - 1].status);