Code path analysis for (a && b) ?? c

[mdjermanovic]

Tell us about your environment

• ESLint Version: v7.7.0
• Node Version: v12.14.0
• npm Version: 6.13.4

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

default

Please show your full configuration:

Configuration

module.exports = {
  parserOptions: {
    ecmaVersion: 2020
  }
};

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

(a && b) ?? c;

The rest of the bug report template isn't quite suitable for this issue.

Code path analysis gives the following:

DOT

digraph {
node[shape=box,style="rounded,filled",fillcolor=white];
initial[label="",shape=circle,style=filled,fillcolor=black,width=0.25,height=0.25];
final[label="",shape=doublecircle,style=filled,fillcolor=black,width=0.25,height=0.25];
s1_1[label="Program:enter\nExpressionStatement:enter\nLogicalExpression:enter\nLogicalExpression:enter\nIdentifier (a)"];
s1_2[label="Identifier (b)\nLogicalExpression:exit"];
s1_3[label="Identifier (c)"];
s1_4[label="LogicalExpression:exit\nExpressionStatement:exit\nProgram:exit"];
initial->s1_1->s1_2->s1_3->s1_4;
s1_1->s1_4;
s1_2->s1_4->final;
}

Image

This would be correct for (a || b) ?? c, but I think it isn't entirely correct for (a && b) ?? c since there should be a path from a to c that doesn't go through b:

(null && console.log("b")) ?? console.log("c"); // logs only "c"

[btmills]

This is a similar issue to #13634. I believe we can fix both in semver-minor changes.

[eslint-deprecated]

Unfortunately, it looks like there wasn't enough interest from the team
or community to implement this change. While we wish we'd be able to
accommodate everyone's requests, we do need to prioritize. We've found
that issues failing to reach accepted status after 21 days tend to
never be accepted, and as such, we close those issues.
This doesn't mean the idea isn't interesting or useful, just that it's
not something the team can commit to.

Thanks for contributing to ESLint and we appreciate your understanding.

[aladdin-add]

friendly ping @mdjermanovic is this still an issue we want to address?

[nzakas]

Yes, we should fix this.

[nzakas]

Working on this.