LSP Custom Requests — URI Wire Format

Why it breaks

• Connection.sendRequest(method, params) runs JSON.stringify(params).
• vscode-uri Uri.toJSON() returns UriComponents (plain data). See microsoft/vscode-uri src/uri.ts.
• Receiver gets a plain object — no prototype, no toString/fsPath.
• uri.toString() → "[object Object]" → fs.stat/readFile fails with EntryNotFound.

Rules

• Never call .toString() / .fsPath on a URI received over the wire without rehydrating first.
• Type URI params as UriComponents (derived); revive on receive.

Pattern — UriComponents + revive

Params type derived from URI.toJSON: