7.0.0-dev.20260403.1 lsp diagnostic params fail to unmarshall in Helix

[kanashimia]

Updating from 7.0.0-dev.20260401.1 to 7.0.0-dev.20260403.1 causes the following error:

tsgo <- InvalidParams: InvalidParams: json: cannot unmarshal JSON object into Go lsproto.Message: InvalidParams: failed to unmarshal *lsproto.DocumentDiagnosticParams: json: cannot unmarshal into Go lsproto.DocumentDiagnosticParams within "/previousResultId": null value is not allowed for field "previousResultId"

Which causes diagnostics to not be displayed, this is on helix 25.07.1 (3d68e0a3) which is a build from master.
I'm not sure if it is a bug here or in the Helix editor, but seems like a regression.

[jakebailey]

This changed in #3313.

The spec says:

export interface DocumentDiagnosticParams extends WorkDoneProgressParams,
	PartialResultParams {
	textDocument: TextDocumentIdentifier;
	identifier?: string;
	previousResultId?: string;
}

null is not allowed for previousResultId; your editor should not be passing it.

https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#documentDiagnosticParams

[kanashimia]

Ok, thanks @jakebailey for a pointer, I will open an issue there.