fix: #2642 root element have no __typename field

[mlecoq]

Resolves #2642

[changeset-bot]

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Latest commit: 5c0c4c3

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@urql/core	Minor

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[JoviDeCroock]

Mind adding a test for this?

[mlecoq]

Mind adding a test for this?

Hi, does it look good to you after last changes ?

[kitten]

Hiya 👋 Sorry about that regression. That was my bad

Unfortunately, the fix here you've got now has a small problem as well.
You've got the Date instance check there, however, exchanges may add any kind of objects into the result, making the recursion now potentially dangerous and destroying instances or even recursing infinitely if instances with recursive properties are added to a result 😅

What I forgot when refactoring is that we skip adding a __typename field to the root selection set. However, what we can do about this is skip the __typename check for the first run of this function, which we could do with an additional argument for instance

[mlecoq]

Ok I'll change it