{
  "jsonrpc": "2.0",
  "method": "textDocument/didOpen",
  "params": {
    "textDocument": {
      "uri": "file:///a/file.ts",
      "languageId": "typescript",
      "version": 1,
      "text": "interface A {\n  b?: string;\n}\n\nconst o: A = {};\n\nfunction c(s: string) {}\n\nc(o.)"
    }
  }
}