new stream.Transform([options])

• options <Object> 传给 Writable 和 Readable 构造函数。 还具有以下字段：
  • transform <Function> stream._transform() 方法的实现。
  • flush <Function> stream._flush() 方法的实现。

const { Transform } = require('stream');

class MyTransform extends Transform {
  constructor(options) {
    super(options);
    // ...
  }
}

或者，当使用 ES6 之前的风格构造函数时：

const { Transform } = require('stream');
const util = require('util');

function MyTransform(options) {
  if (!(this instanceof MyTransform))
    return new MyTransform(options);
  Transform.call(this, options);
}
util.inherits(MyTransform, Transform);

或者，使用简化的构造函数方法：

const { Transform } = require('stream');

const myTransform = new Transform({
  transform(chunk, encoding, callback) {
    // ...
  }
});

• options <Object> Passed to both Writable and Readable constructors. Also has the following fields:
  • transform <Function> Implementation for the stream._transform() method.
  • flush <Function> Implementation for the stream._flush() method.

const { Transform } = require('stream');

class MyTransform extends Transform {
  constructor(options) {
    super(options);
    // ...
  }
}

Or, when using pre-ES6 style constructors:

const { Transform } = require('stream');
const util = require('util');

function MyTransform(options) {
  if (!(this instanceof MyTransform))
    return new MyTransform(options);
  Transform.call(this, options);
}
util.inherits(MyTransform, Transform);

Or, using the simplified constructor approach:

const { Transform } = require('stream');

const myTransform = new Transform({
  transform(chunk, encoding, callback) {
    // ...
  }
});