addTypename

When to add __typename. One of "always", "ifFragments", "ifAbstract" or "ifPolymorphic"

• "always": Add '__typename' for every composite field

• "ifFragments": Add '__typename' for every selection set that contains fragments (inline or named) This causes cache misses when introducing fragments where no fragment was present before and will be certainly removed in a future version.

• "ifAbstract": Add '__typename' for abstract fields, i.e. fields that are of union or interface type Note: It also adds '__typename' on fragment definitions that satisfy the same property because fragments could be read from the cache, and we don't have a containing field in that case.

• "ifPolymorphic": Add '__typename' for polymorphic fields, i.e. fields that contains a subfragment (inline or named) whose type condition isn't a super type of the field type. If a field is monomorphic, no '__typename' will be added. This adds the bare minimum amount of __typename but the logic is substantially more complex and it could cause cache misses when using fragments on monomorphic fields because __typename can be required in some cases.

Note: It also adds '__typename' on fragment definitions that satisfy the same property because fragments could be read from the cache, and we don't have a containing field in that case.

Default value: "ifFragments"