AsyncTracker

The AsyncTracker provides a mechanism for tracking asynchronous operations in Node.js. It uses the async_hooks module to track the lifecycle of asynchronous resources.

Install

npm i @j-o-r/asynctracker --save

Constructor

• AsyncTracker()
  • Constructs a new instance of the AsyncTracker.

Methods

• enable(type: string)

  • Enables tracking of asynchronous methods. Optionally, only methods of a specified type can be tracked.
  • type (optional): The type of asynchronous method to track. If not specified, all types are tracked.

• disable()

  • Disables the tracking of asynchronous methods.

• reset()

  • Clears all tracked asynchronous methods.

• report(verbose: boolean)

  • Prints an overview of active asynchronous calls.
  • verbose (optional): If true, prints detailed information. Defaults to false.

• getUnresolved(type: string)

  • Returns an array of unresolved asynchronous methods, optionally filtered by type.
  • type (optional): The type of asynchronous methods to filter by.

• getTypeDescription(type: string)

  • Returns a description of the specified asynchronous method type.
  • type: The type of asynchronous method.

• addCustomType(type: string, description: string)

  • Adds or overwrites a custom type for asynchronous methods.
  • type: The type of the asynchronous method.
  • description: The description of the type.

Usage Example

import AsyncTracker from '@j-o-r/asynctracker';

const tracker = new AsyncTracker();
tracker.enable();
// Perform asynchronous operations...
const count = tracker.report(true); // Prints detailed information about active async calls

Additional Information

• The AsyncTracker class uses various predefined types for asynchronous operations like Promise, Timeout, Immediate, etc.
• Custom types can be added using the addCustomType method for specialized tracking.
• The report method is useful for debugging purposes to get insights into ongoing asynchronous operations.

TYPES

• TIMERWRAP: setTimeout(), setInterval()
• PROMISE: Promise
• IMMEDIATE: setImmediate()
• PROCESSNEXTTICK: process.nextTick()
• TICKOBJECT: Used internally by process.nextTick()
• SCRIPT: vm.Script.runInThisContext()
• PROMISEEXECUTOR: Used internally by Promise
• TIMEOUT: setTimeout()
• PIPECONNECTWRAP: Used by pipes
• PIPEWRAP: Used by pipes
• TCPCONNECTWRAP: Used by TCP sockets
• TCPWRAP: Used by TCP sockets
• GETADDRINFOREQWRAP: Used by DNS queries
• GETNAMEINFOREQWRAP: Used by DNS queries
• QUERYWRAP: Used by DNS queries
• FSREQCALLBACK: Used by FS operations
• FILEHANDLE: Used by file handles
• SIGNALWRAP: Used by signal handlers
• HTTPPARSER: Used by HTTP parsing
• HTTP2SESSION: Used by HTTP/2 sessions
• HTTP2STREAM: Used by HTTP/2 streams
• ZLIB: Used by Zlib
• TTYWRAP: Used by TTY handles
• UDPSENDWRAP: Used by UDP sockets
• UDPWRAP: Used by UDP sockets
• WRITEWRAP: Used by process.stdout and process.stderr
• SHUTDOWNWRAP: Used by socket.end()