Combining .ProjectInto<>() with Select() on >5.4.2?

[wagich]

After upgrading from 5.4.1 to the latest version, a query that was using ProjectInto (to retrieve stored fields) then Select on top of that stopped working and weirdly started throwing JsonSerializationException.

#15105 seems to be about the same thing, but was closed as "don't do that". My problem is that I have a reusable "base query" that by default has to retrieve fields stored only in the index (which doesn't work without ProjectInto). This query is then used from other places and might also be customized further using Select() before being executed.

Is it possible to restore the previous behaviour? IMHO it was more logical, especially because there isn't any indication that they can't be combined.
Or does anyone have a workaround that enables both retrieving stored index fields without specifying a projection and also enables customization?

For more context: I've isolated the behaviour change to commit 7e62f91
and created a test case at https://gist.github.com/wagich/8a1ad17e8b266d2176acf96636a50267

[garayx]

Hi
Both ProjectInto() & Select() are doing projection so you should have only one of them in the query.

You are using Select() for customization, you can also return the stored fields by using Select():
https://ravendb.net/docs/article-page/5.1/Csharp/indexes/querying/projections#example-ii---projecting-stored-fields

[ayende]

The actual problem here is that Select is additive. So you are actually returning all the fields of the item.
Then the deserialization code sees that there are multiple values there, and we don't try to get just the value to desarialize.

[ayende]

#15638

[wagich]

Thank you for the fast fix!