Passing arguments to vscode command in code action from non-js language server

When a language server (implemented in OCaml) sends a code action with a command editor.action.goToLocations, it needs to pass various arguments to the command: uri, position, locations, multiple (optional), noResultsMessage (optional), and openInPeek (optional). From diving into implementation, I have several questions:

1. AFAIU, uri, position, locations should be of format supported by vscode, e.g., position is not common position format for lsp: {line: number, character: number} BUT {lineNumber: number, column: number}. Shouldn't command arguments be more lsp friendly and support common to LSP format?

2. More importantly, when I pass uri, AFAIU, vscode has the following check for it (from here)

static isUri(thing: any): thing is URI {
		if (thing instanceof URI) {
			return true;
		}
		if (!thing) {
			return false;
		}
		return typeof (<URI>thing).authority === 'string'
			&& typeof (<URI>thing).fragment === 'string'
			&& typeof (<URI>thing).path === 'string'
			&& typeof (<URI>thing).query === 'string'
			&& typeof (<URI>thing).scheme === 'string'
			&& typeof (<URI>thing).fsPath === 'string'
			&& typeof (<URI>thing).with === 'function'
			&& typeof (<URI>thing).toString === 'function';
	}

How does one send this json such that this returns true, taking into account with and toString properties?

I see there is some code that converts json to js objects, but it's minimalistic

I think that given vscode has a limited number of commands, the code could specialize handling of arguments to make it more friendly or there is some other easier way to go about this?

Start with client/src/common/codeConverter.ts around the referenced command conversion and compare it with the VS Code URI implementation linked in the issue. Trace how code-action command arguments cross the language-server boundary, including positions and URI values. Done should establish a supported representation or conversion approach for these arguments and clarify the expected behavior for optional parameters.