Iroh is a dynamic code analysis tool for JavaScript. Iroh allows to record your code flow in realtime, intercept runtime values and manipulate program behaviour on the fly.

Installation:

npm install iroh

or alternatively the browser distribution from here.

Example:

You can play with some live examples here and you can clone them from here.

(A simple textual model is used here)

Input

function factorial(n) {
  if (n === 0) return 1;
  return n * factorial(n - 1);
};
factorial(3);

Output

call factorial ( [3] )
  call factorial ( [2] )
    call factorial ( [1] )
      call factorial ( [0] )
        if
        if end
      call factorial end -> [1]
    call factorial end -> [1]
  call factorial end -> [2]
call factorial end -> [6]

Usage:

• Runtime call tree graphs
• Runtime type checking
• Runtime code quality
• Runtime test cases
• Realtime code visualizations
• Intercept eval, setTimeout etc.
• Intercept and manipulate code/data on the fly
• Visual learning