debugtrace-js v2.2.0

debugtrace-js

Japanese

debugtrace-js is a library that outputs trace logs when debugging JavaScript programs. It is available on Node.js 16 or later. By embedding debugtrace.enter() and debugtrace.leave() at the start and end of functions, you can output the execution status of the JavaScript program under development to the log.

1. Features

• Automatically outputs invoker's function name, source file and line number.
• Automatically indents the log with nesting methods and objects.
• There are no dependent libraries at run time.

2. How to use

Do the following for debug target and related methods.

1. Insert debugtrace.enter() at the beginning of functions.
2. Insert debugtrace.leave() at the end of functions or just before the return statement.
3. Insert debugtrace.print('foo', foo) to output arguments, local variables and return value to the log if necessary.

The following is an example of JavaScript source used debugtrace-js methods and the log of when it has been executed.

// ReadmeExample.js
const debugtrace = require('debugtrace-js') // TODO: Debug

class Contact {
  constructor(id, firstName, lastName, birthday) {
    this.id = id
    this.firstName = firstName
    this.lastName = lastName
    this.birthday = birthday
  }
}

const func2 = () => {
  debugtrace.enter() // TODO: Debug
  let contacts = [
    new Contact(1, 'Akane' , 'Apple', new Date(Date.UTC(1991, 2, 3))),
    new Contact(2, 'Yukari', 'Apple', new Date(Date.UTC(1992, 3, 4)))
  ]
  debugtrace.print('contacts', contacts) // TODO: Debug
  debugtrace.leave() // TODO: Debug
}

const func1 = () => {
  debugtrace.enter() // TODO: Debug
  debugtrace.printMessage('Hello, World!')
  func2()
  debugtrace.leave() // TODO: Debug
}

func1()

2025-02-11 15:49:38.591+09:00 debugtrace-js 2.2.0 on Node.js 22.13.1
2025-02-11 15:49:38.617+09:00
2025-02-11 15:49:38.618+09:00 Enter func1 (ReadmeExample.js:25)
2025-02-11 15:49:38.618+09:00 | Hello, World! (ReadmeExample.js:26)
2025-02-11 15:49:38.618+09:00 | Enter func2 (ReadmeExample.js:15)
2025-02-11 15:49:38.620+09:00 | | contacts = [
2025-02-11 15:49:38.620+09:00 | |   (Contact){
2025-02-11 15:49:38.620+09:00 | |     id: 1, firstName: 'Akane', lastName: 'Apple',
2025-02-11 15:49:38.620+09:00 | |     birthday: 1991-03-03 09:00:00.000+09:00
2025-02-11 15:49:38.621+09:00 | |   },
2025-02-11 15:49:38.621+09:00 | |   (Contact){
2025-02-11 15:49:38.621+09:00 | |     id: 2, firstName: 'Yukari', lastName: 'Apple',
2025-02-11 15:49:38.621+09:00 | |     birthday: 1992-04-04 09:00:00.000+09:00
2025-02-11 15:49:38.622+09:00 | |   }
2025-02-11 15:49:38.622+09:00 | | ] (ReadmeExample.js:20)
2025-02-11 15:49:38.622+09:00 | Leave func2 (ReadmeExample.js:21) duration: 00:00:00.004
2025-02-11 15:49:38.622+09:00 Leave func1 (ReadmeExample.js:28) duration: 00:00:00.004

3. Function List

This library has the following methods. These have no return value.

4. Properties of debugtrace-js

The following properties can be specified for on debugtrace-js.

5. License

MIT ライセンス(MIT)

(C) 2015 Masato Kokubo

6. Release Notes

debugtrace-js 2.2.0 - February 16, 2025

• The following properties have been deleted.

  • debugtrace.minimumOutputLengthAndSize
  • debugtrace.minimumOutputStringLength

• The default values ​​of the following properties have been changed. |Property name |Default value|Old default value| |:---------------------------|------------:|----------------:| |debugtrace.collectionLimit| 128| 512| |debugtrace.stringLimit | 256| 8192|

• The printOptions argument (optional) has been added to the print function.

debugtrace-js 2.1.2 - March 13, 2022

• The print and printMessage functions now return the argument value.

debugtrace-js 2.1.1 - October 9, 2021

• Fixed a bug that an exception is thrown when outputting a type name.
• Changed to output Node.js version at startup.

debugtrace-js 2.1.0 - August 9, 2021

• Improved function output (output only the first line of the function definition)
• Added the basicPrint function
• Improved the line break handling of data output

debugtrace-js 2.0.0 - August 2, 2020

• Supported Node.js 10 or later
• Improved the line break handling of data output