import test from 'node:test';
import assert from 'node:assert/strict';
import { EventEmitter } from 'node:events';
import policyModule from '../src/main/process-error-policy.cjs';

const { installOutputPipeGuards, isBrokenPipeError } = policyModule;

test('broken output pipes are recognized without treating unrelated failures as EPIPE', () => {
  assert.equal(isBrokenPipeError(Object.assign(new Error('closed'), { code: 'EPIPE' })), true);
  assert.equal(isBrokenPipeError(Object.assign(new Error('denied'), { code: 'EACCES' })), false);
  assert.equal(isBrokenPipeError(null), false);
});

test('output pipe guard absorbs EPIPE and can be cleanly removed', () => {
  const stdout = new EventEmitter();
  const stderr = new EventEmitter();
  const observed = [];
  const remove = installOutputPipeGuards({ stdout, stderr, onBrokenPipe: (error) => observed.push(error.code) });

  stdout.emit('error', Object.assign(new Error('closed'), { code: 'EPIPE' }));
  stderr.emit('error', Object.assign(new Error('closed'), { code: 'EPIPE' }));
  assert.deepEqual(observed, ['EPIPE', 'EPIPE']);
  remove();
  assert.equal(stdout.listenerCount('error'), 0);
  assert.equal(stderr.listenerCount('error'), 0);
});