$expand is reported as enum while it is actually string

[sherlock1982]

Current behavior:
$expand is enum.

Expected behavior:
$expand is string because you can have complex expressions in $expand like for example $expand=Groups($expand=Members)

[darrelmiller]

If we updated the schema to be like this it would allow us to provide a list of properties that are expandable but also indicate that each expand property could be a more complex syntax.

          schema:
            uniqueItems: true
            type: array
            items:
              anyOf:
                - enum:
                    - '*'
                    - serviceAnnouncement
                - type: string

Thoughts?

[baywet]

adding some more context here due to
microsoft/kiota#4265
microsoftgraph/msgraph-sdk-typescript#512

currently expand, orderby, select are projected as arrays of enums.
In all three cases this is wrong because of nested expands/selects and nested properties ordering

e.g.
$expand=Groups($expand=Members)
$select=manager($select=firstName)
$orderBy=manager.firstName

projecting all possibilities for all sub-properties combinations would lead to huge and hard to read enums
projecting only the first level properties like today is constraining.
projecting only the first level sub-properties with a oneOf with a string (variation of what Darrel proposed) I believe will lead to confusion (is this only what's supported?), won't be useful for validation or code generation purposes.

I propose we simply project those three as arrays of strings instead. Which will have the additional benefit of making Microsoft Graph descriptions quite smaller too.

[baywet]

We do have a hard dependency on that though, GE relies on this to auto completion.
We need to tie this new behaviour to a conversion setting switch (true by default, false for GE) "EmitExpandSelectAndOrderByAsStrings" (or a better name)

[andrueastman]

I propose we simply project those three as arrays of strings instead. Which will have the additional benefit of making Microsoft Graph descriptions quite smaller too.

+1