// Regression test for https://github.com/microlinkhq/youtube-dl-exec/issues/246
// Child process stdio properties should be enumerable for Object.assign() compatibility

import { expect, test } from "bun:test";
import { spawn } from "child_process";

test("child process stdio properties should be enumerable for Object.assign()", () => {
  const child = spawn(process.execPath, ["-e", 'console.log("hello")']);

  // The real issue: stdio properties must be enumerable for Object.assign() to work
  // This is what libraries like tinyspawn depend on
  expect(Object.keys(child)).toContain("stdin");
  expect(Object.keys(child)).toContain("stdout");
  expect(Object.keys(child)).toContain("stderr");
  expect(Object.keys(child)).toContain("stdio");

  // Property descriptors should show enumerable: true
  for (const key of ["stdin", "stdout", "stderr", "stdio"] as const) {
    expect(Object.getOwnPropertyDescriptor(child, key)?.enumerable).toBe(true);
  }
});

test("Object.assign should copy child process stdio properties", () => {
  const child = spawn(process.execPath, ["-e", 'console.log("hello")']);

  // This is what tinyspawn does: Object.assign(promise, childProcess)
  const merged = {};
  Object.assign(merged, child);

  // The merged object should have the stdio properties
  expect(merged.stdout).toBeTruthy();
  expect(merged.stderr).toBeTruthy();
  expect(merged.stdin).toBeTruthy();
  expect(merged.stdio).toBeTruthy();

  // Should maintain stream functionality
  expect(typeof merged.stdout.pipe).toBe("function");
  expect(typeof merged.stdout.on).toBe("function");
});

test("tinyspawn-like library usage should work", () => {
  // Simulate the exact pattern from tinyspawn library
  let childProcess;
  const promise = new Promise(resolve => {
    childProcess = spawn(process.execPath, ["-e", 'console.log("test")']);
    childProcess.on("exit", () => resolve(childProcess));
  });

  // This is the critical line that was failing in Bun
  const subprocess = Object.assign(promise, childProcess);

  // Should have stdio properties immediately after Object.assign
  expect(subprocess.stdout).toBeTruthy();
  expect(subprocess.stderr).toBeTruthy();
  expect(subprocess.stdin).toBeTruthy();

  // Should still be a Promise
  expect(subprocess instanceof Promise).toBe(true);

  // Should have stream methods available
  expect(typeof subprocess.stdout.pipe).toBe("function");
  expect(typeof subprocess.stdout.on).toBe("function");
});