Watched variable declared in a while retains its watched value across iterations

[louis-bompart]

Version

v18.16.0

Platform

Microsoft Windows NT 10.0.19044.0 x64

Subsystem

Debugger

What steps will reproduce the bug?

1. Create a file named index.js containing the following script:

   let i = 5;
   while (--i > 0) {
     const foo = "bar" + i;
   }

2. Inspect it using node inspect index.js

3. watch foo: watch('foo'). Optionally, watch('i') too.

4. Go to l3 for the first time, assert that foo = undefined)

5. Continue until you reach l3 again: the watched value of foo is then bar4 (and i=3): the debugger show the foo declared in the previous iteration

How often does it reproduce? Is there a required condition?

The reproducing steps are systematic, I reproduced similar behavior in longer scripts too

What is the expected behavior? Why is that the expected behavior?

I'd expect the watch value to stay undefined or in error until the declaration statement

What do you see instead?

Additional information

No response

[cola119]

Safari can correctly watch the variable. This looks like a bug in V8 engine.