I'm implementing a "fix lint errors on save" feature in my language server. The simplest way to do this seems to be listening for IConnection#onWillSaveTextDocumentWaitUntil and responding with some TextEdits, but my handler is never called. Same thing for IConnection#onWillSaveTextDocument and TextDocuments#onWillSaveWaitUntil.

The IConnection#onDidSaveTextDocument handler is called, and the rest of my language server is working fine (autocomplete, diagnostics, code actions, etc etc).

I'm guessing that there's probably somewhere that I need to opt into receiving these events, but I've been poking around all morning and haven't found anything.

More details:

• my textDocumentSync capability is TextDocuments#syncKind which I think is Full
• transport layer is stdio
• VSCode 1.18.1, [email protected], [email protected], [email protected], [email protected]