Node.js Stream.pipeline() Method

The stream.pipeline() method is a module method that is used to the pipe by linking the streams passing on errors and accurately cleaning up and providing a callback function when the pipeline is done. 

Syntax:

stream.pipeline(...streams, callback)

Parameters: This method accepts two parameters as mentioned above and described below.

• ...streams: These are two or more streams that are to be piped together.
• callback: This function is called when the pipeline is fully done and it shows an 'error' if the pipeline is not accomplished.

Return Value: It returns a cleanup function. 

The below examples illustrate the use of the stream.pipeline() method in Node.js: 

Example 1: 

Output:

Promise { }
pipeline accomplished.

Example 2: 

Output: Here, the order of streams is not proper while piping so an error occurs.

Promise { }
pipeline failed with error: Error [ERR_STREAM_CANNOT_PIPE]: Cannot pipe, not readable
 at WriteStream.Writable.pipe (_stream_writable.js:243:24)
 at pipe (internal/streams/pipeline.js:57:15)
 at Array.reduce ()
 at pipeline (internal/streams/pipeline.js:88:18)
 at Promise (internal/util.js:274:30)
 at new Promise ()
 at pipeline (internal/util.js:273:12)
 at run (/home/runner/ThirstyTimelyKey/index.js:33:11)
 at /home/runner/ThirstyTimelyKey/index.js:45:5
 at Script.runInContext (vm.js:133:20)

Reference: https://nodejs.org/api/stream.html#stream_stream_pipeline_streams_callback.