src/vs/base/common/resources.ts/ExtUri/addTrailingPathSeparator
class ExtUri:	addTrailingPathSeparator(resource: URI, sep: string = paths.sep): URI {
		let isRootSep: boolean = false;
		if (resource.scheme === Schemas.file) {
			const fsp = originalFSPath(resource);
			isRootSep = ((fsp !== undefined) && (fsp.length === extpath.getRoot(fsp).length) && (fsp[fsp.length - 1] === sep));
		} else {
			sep = '/';
			const p = resource.path;
			isRootSep = p.length === 1 && p.charCodeAt(p.length - 1) === CharCode.Slash;
		}
		if (!isRootSep && !hasTrailingPathSeparator(resource, sep)) {
			return resource.with({ path: resource.path + '/' });
		}
		return resource;
	}