Function getSiblingDirectoryPrefix

src/node/runtime/atomicWriteTempPath.ts:3–10

(filePath: string)

import * as crypto from "crypto";

function getSiblingDirectoryPrefix(filePath: string): string {
  const lastSeparatorIndex = Math.max(filePath.lastIndexOf("/"), filePath.lastIndexOf("\\"));
  if (lastSeparatorIndex === -1) {
    return "";
  }

  return filePath.slice(0, lastSeparatorIndex + 1);
}

/**
 * Use a short, collision-proof sibling temp path so concurrent writers never