'use strict'; const common = require('../common'); const assert = require('assert'); const spawn = require('child_process').spawn; const stream = require('stream'); const fs = require('fs'); // require('internal/fs/utils').SyncWriteStream is used as a stdio // implementation when stdout/stderr point to files. if (process.argv[2] === 'child') { // Note: Calling console.log() is part of this test as it exercises the // SyncWriteStream#_write() code path. console.log(JSON.stringify([process.stdout, process.stderr].map((stdio) => ({ instance: stdio instanceof stream.Writable, readable: stdio.readable, writable: stdio.writable, })))); return; } const tmpdir = require('../common/tmpdir'); tmpdir.refresh(); const filename = tmpdir.resolve('stdout'); const stdoutFd = fs.openSync(filename, 'w'); const proc = spawn(process.execPath, [__filename, 'child'], { stdio: ['inherit', stdoutFd, stdoutFd ] }); proc.on('close', common.mustCall(() => { fs.closeSync(stdoutFd); assert.deepStrictEqual(JSON.parse(fs.readFileSync(filename, 'utf8')), [ { instance: true, readable: false, writable: true }, { instance: true, readable: false, writable: true }, ]); }));