Migration Guide

From 2.x to 3.0

3.0 contains very few breaking changes.

useSubscription() reducer arguments

For better TypeScript detection with TypedDocuments and more versastility with the reducer function, the argument order has been flipped.

• So instead of getting the previous value as the first argument, you will get the new subscription result instead.
• The second argument will recieve the previous reduced value.

This makes the reducer more flexible as it can now be used as either a callback for when incoming data is received or a mapper if you only plan to use the last result or map it to a different value, or a reducer that combines the previous and incoming values if applicable.

Here is how to migrate:

jsfunction reduceMessages(old, incoming) {  
function reduceMessages(incoming, old) {  
  // reduce values
}

onSuccess query hook renamed

For consistency, the recently introduced onSuccess option on useQuery has been renamed to onData to be more consistent with other naming conventions.

Here is how to migrate:

jsimport { useQuery } from 'villus';

useQuery({
  query: GetPostById,
  variables,
  onSuccess: data => console.log(data), 
  onData: data => console.log(data), 
});