When creating a record directly against local cache, Apollo behaves unexpectedly if one of the optional fields is missing

Intended outcome: To create a record locally which will be synced at a later time to the server. The goal is to read from cache, append to the cached array and save directly to cache.

Actual outcome: When creating the record locally as described here Apollo “empties out” my local query cache.

This issue only happens if I create a record locally which misses any of the fields specified by the original query.

How to reproduce the issue:

Use a query such as this to fetch data from server and into local cache:

  query fetchAssetsQuery {
    assets {
        contentState
        id
        createdAt
    }

Now create a new record locally which is missing the createdAt prop as such:

      let assets = client.readQuery({
        query: fetchAssetsQuery
      }).assets;

    client.writeQuery({
      query: fetchAssetsQuery,
      data: {
        assets: [{
          id: id,
        }, ...assets]
      }
    });

Finally, sync to the server as such:

      return mutate({
        variables: assetListInput: {
               assets: assets
        },
        updateQueries: {
          getUserAssets: (previousQueryResult, { mutationResult }) => {
            let currentAssets = previousQueryResult.assets;
            return { assets: currentAssets };
          }
        }
      })

This will result in the query turning into an empty array. To be more specific, updateQueries does not get executed here.

However, If I create the local record with the missing createdAt prop, this issue is resolved.

There are certain props that I’d like the server to create such as createdAt.

[Poincare]

If I’m understanding correctly, this is intended behavior since if you update the store with a result that’s missing createdAt, it’s going to break the existing query observer on the page associated with the query containing the createdAt field.

You could just set your createdAt field to a null-like value initially and then insert it once it hits the server and comes back.

[yattias]

Got it. Cool. Just wanted to make sure it’s being tracked.