src/vs/workbench/services/path/common/pathService.ts/AbstractPathService/fileURI
class AbstractPathService:	async fileURI(_path: string): Promise<URI> {
		let authority = '';

		// normalize to fwd-slashes on windows,
		// on other systems bwd-slashes are valid
		// filename character, eg /f\oo/ba\r.txt
		const os = await this.resolveOS;
		if (os === OperatingSystem.Windows) {
			_path = _path.replace(/\\/g, '/');
		}

		// check for authority as used in UNC shares
		// or use the path as given
		if (_path[0] === '/' && _path[1] === '/') {
			const idx = _path.indexOf('/', 2);
			if (idx === -1) {
				authority = _path.substring(2);
				_path = '/';
			} else {
				authority = _path.substring(2, idx);
				_path = _path.substring(idx) || '/';
			}
		}

		return URI.from({
			scheme: Schemas.file,
			authority,
			path: _path,
			query: '',
			fragment: ''
		});
	}