Exercism-JS/translation-service/HINTS.md

Hints

1. Fetch a translation, ignoring the quality

• Promises are chainable, for example by using .then.
• Promises will forward any value. That means that if a promise resolves, it will forward that value until it reaches the end of the chain or a .then, which receives the value as its argument.
• Promises will forward any error. That means that if a promise rejects, it will forward that rejection until it reaches the end of the chain or a .catch, which receives the value as its argument and can handle it.

2. Fetch a batch of translations, all-or-nothing

• To return a promise with an error, create a Promise that is rejected from the start.
• There is a helper method on Promise that waits for an array of promises to resolve before it resolves itself.

3. Request a translation, retrying at most 2 times

• Convert the callback to a promise using the new Promise constructor.

4. Fetch a translation, inspect the quality, or request it

• Instead of nesting .then and/or .catch, .then takes a second argument which catches everything before (earlier in the chain), ignoring errors in the first argument of .then.