Handling @urql/exchange-populate

[zachasme]

Hi there!

URQL can automatically populate mutations using the @populate directive:

mutation CreateProduct($input: CreateProductInput!) {
  createProduct(input: $input) {
    product @populate
  }
}

but it breaks our codegen setup: GraphQLDocumentError: Field "product" of type "Product!" must have a selection of subfields. Did you mean "product { ... }"?

Is it possible to ignore fields with the @populate directive? We still wish to generate typescript types for mutation inputs.

[dotansimha]

Interesting. @kitten @JoviDeCroock can you please share an overview of how this works? Just spread the entire selection set? how does it works? Thanks!

[JoviDeCroock]

The populate exchange tracks the fields that are currently queried for a certain mutation.

So let's say we query todos { id name } then it will automatically say updateTodo { id name }. If we add another observed query with for instance todos { id name createdAt } then this would be updateTodo { id name createdAt }.

This is how it currently behaves, we are currently expanding on this behavior with: urql-graphql/urql#964 which would incorporate populating the viewer field and another one that would create queries.