Rule Change: no-constant-binary-expression should report `<expr1> ?? <non-nullish> ?? <expr2>`

Rule details

Inform developer of potentially unnecessary nullish coalescing operator

Related ECMAScript feature

Nullish coalesing operator

What type of rule is this?

Suggests an alternate way of doing something

Example code

// fail
window.abc ?? "any non-nullish value" ?? "any non-nullish value" // warn (the last nullish coalesing operator will never be used)
window.abc ?? undefined ?? "any non-nullish value" // warn (the first nullish coalescing operator is skipped)
window.abc ?? null ?? "any non-nullish value" // warn (the first nullish coalescing operator is skipped)

Why should this rule be in the core instead of a plugin?

I don’t know.

Participation

• I am willing to submit a pull request to implement this rule.

Additional comments

No response

[mdjermanovic]

Updated the title and marked accepted. @amareshsm this is now ready to implement.

[amareshsm]

In case we are updating the no-constant-binary-expression rule to report an unnecessary nullish coalescing operator then I will work this.