NodeJS - a step-by-step debugger for NodeJS

Question

I\'m looking for effective way for step-by-step debugging NodeJS server code. At this moment I use dozens of console.log()\'s and it\'s extremely hard. The perfect tool is o

Answer 1

node inspect built-in CLI step debugging

It took a while, but at some point Node finally added built-in debugging:

node inspect main.js

and this leaves you at the first line of the program.

Navigate with:

• n step to next line
• s step into function
• c continue
• o step out
• h get help

In order to view variables or inject code, you need to first enter REPL mode with:

repl

and then you can run commands as in a node interactive session, e.g. to see the value of a variable just write the variable name:

myvar

It is awkward to have to type those four characters repl all the time, but I don't know any alternative.

You can also add a debugger statement to where you want to break in the program after a c:

const i = 1;
debugger;
i = 2;

Related question: How do I debug Node.js applications?

Tested in Node.js v10.15.1, Ubuntu 19.10.