Practice: Create and Handle Promises

In this practice, you will work on creating and handling Promises.

Set up

Clone the project from the starter.

Phase 1: Workout

Implement the code in phase-1.js.

stretch

Write a function called stretch. It should:

• return a promise
• fulfill the promise after 1 second
• print "done stretching" once the promise is fulfilled

runOnTreadmill

Write a function called runOnTreadmill. It should:

• return a promise
• fulfill the promise after 0.5 seconds
• print "done running on treadmill" once the promise is fulfilled

liftWeights

Write a function called liftWeights. It should:

• return a promise
• fulfill the promise after 2 seconds
• print "done lifting weights" once the promise is fulfilled

workout

Write a function called workout that runs the above functions in a way that ensures you begin running on the treadmill after you've finished stretching. Begin lifting weights after running on the treadmill. Print "done working out" after you've finished lifting weights.

Test your code

Run the file (node phase-1.js) and check your output against the expected output. workout() should print out the following output to the terminal:

done stretching
done running on treadmill
done lifting weights
done working out

Phase 2: Effective Workout

In Phase 2, you will improve upon phase 1 in phase-2.js. You are not expected to complete this now. This is phase should be used for additional promise practice in studying for the assessment.

Adjust your workout function so that it takes in a specific amount of time that you have available for the entire workout

Given the following new rules, have each promise resolve with the amount of time left by decrementing each action by its specific amount of time

New Rules:

1. you must stretch for 1 second
2. you must run on treadmill for 0.5 seconds
3. you must lift weights for 2 seconds

If the time needed to complete the current action exceeds the amount of time left, reject the promise and provide a reason.

For example, working out for 500 milliseconds should print an error because if you only have 0.5 seconds to workout, you won't have enough time to even stretch.

workout(500);
  // should print out the following:
    // "Error: you dont have enough time to stretch"

But if you work out for 1000 milliseconds, it should print out that you finished stretching, but you don't have enough time to run on the treadmill.

workout(1000);
  // should print out the following:
    // done stretching
    // Error:  you dont have enough time to run on treadmill

Test each function

Comment in each invocation of the workout function listed at the bottom and run the file (node phase-2.js) to see if you get the expected output.