'use strict'; require('../common'); var assert = require('assert'); var Transform = require('stream').Transform; var parser = new Transform({ readableObjectMode: true }); assert(parser._readableState.objectMode); assert(!parser._writableState.objectMode); assert.strictEqual(parser._readableState.highWaterMark, 16); assert.strictEqual(parser._writableState.highWaterMark, 16 * 1024); parser._transform = function(chunk, enc, callback) { callback(null, { val: chunk[0] }); }; var parsed; parser.on('data', function(obj) { parsed = obj; }); parser.end(Buffer.from([42])); process.on('exit', function() { assert.strictEqual(parsed.val, 42); }); var serializer = new Transform({ writableObjectMode: true }); assert(!serializer._readableState.objectMode); assert(serializer._writableState.objectMode); assert.strictEqual(serializer._readableState.highWaterMark, 16 * 1024); assert.strictEqual(serializer._writableState.highWaterMark, 16); serializer._transform = function(obj, _, callback) { callback(null, Buffer.from([obj.val])); }; var serialized; serializer.on('data', function(chunk) { serialized = chunk; }); serializer.write({ val: 42 }); process.on('exit', function() { assert.strictEqual(serialized[0], 42); });