HINTS.md

Hints

General

• Callback functions are functions passed as an argument to a calling function.
• Callback functions must meet the specification of the calling function.
• These callbacks are all synchronous, meaning they all must return a value.

1. Check if the grocer's service is online

• Use the imported API function checkStatus in your function.
• Pass a callback function to checkStatus. It should expect to receive a string argument.
• Return the result from the checkStatus API function.

2. See if the grocer has some fruit

• Use the imported API function checkInventory in your function.
• Create the query object to pass as an argument.
  • Follow the template in the instructions.
• Pass along the callback function to the checkInventory API function.
• Return the result from the checkInventory API function.

3. Create a callback to buy fruit if the inventory is available

• If the err argument is not null, throw a new error using err's message.
  • See Error()
• if the err is null, ignore it and just respond to the value of isAvailable
  • This pattern is sometimes called a Node.js-style callback.
• Return the action determined by isAvailable

4. Put it all together

• Reuse the functions you have already written, composing them together.
• Return the value of the callback function.