`no-unused-vars` false negative with comma operator

Tell us about your environment

• ESLint Version: 7.30.0
• Node Version: v14.x
• npm Version: v6.x
• Operating System: MacOS

What parser (default, @babel/eslint-parser, @typescript-eslint/parser, etc.) are you using? Default

Please show your full configuration:

Configuration

/*eslint no-unused-vars: "error"*/

What did you do? Please include the actual source code causing the issue, as well as the command that you used to run ESLint.

/*eslint no-unused-vars: "error"*/

var z = 0;
z=z+1, z=2;

var x = 0;
x++, x = 2;

var y = 0;
y = y+1;

What did you expect to happen?

no-unused-vars should report allx, y, and z as unused variables.

What actually happened? Please copy-paste the actual, raw output from ESLint.

no-unused-vars is reporting only x and y as unused variables.

Steps to reproduce this issue:

Online Demo

We probably missed addressing this case in https://github.com/eslint/eslint/issues/14325

Are you willing to submit a pull request to fix this bug? Yes

[snitin315]

@ersachin3112 Sure, let us know if you need any help.

[nzakas]

Since this is kind of a continuation of the previous issue, marking as accepted.