This adds a new request `dart/connectToDtd` that lets a client pass a DTD URI to the server. The server will connect to DTD and provide a subset of LSP methods (those that are currently available over LSP-Over-Legacy, minus the `connectToDtd` method itself) to DTD clients.
This works for both LSP and Legacy servers, and the shared tests run against both (where for legacy, the `dart/connectToDtd` request uses the LSP-over-Legacy support).
This is not currently behind a flag, however it won't do much on its own because no clients will make this request. Once we're happy the functioanlity is good we can either agree an SDK version number for IDEs to gate calling this method on, or we can expose a flag in server capabilities (and some equiv for legacy) so the client knows the functionality is available.
Change-Id: I911d37745a1b2685249dd88e4b152c3196ba627c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/379303
Commit-Queue: Keerti Parthasarathy <keertip@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Keerti Parthasarathy <keertip@google.com>
Danny Tuppeny
da414c2957