fix: func-style false positive with arrow functions and super

[mdjermanovic]

Prerequisites checklist

• I have read the contributing guidelines.

What is the purpose of this pull request? (put an "X" next to an item)

[ ] Documentation update
[x] Bug fix (template)
[ ] New rule (template)
[ ] Changes an existing rule (template)
[ ] Add autofix to a rule
[ ] Add a CLI option
[ ] Add something to the core
[ ] Other, please explain:

Tell us about your environment (npx eslint --env-info):

• Node version: v20.12.0
• npm version: 10.5.0
• Local ESLint version: v9.3.0
• Global ESLint version: no
• Operating System: windows

What parser are you using (place an "X" next to just one item)?

[x] Default (Espree)
[ ] @typescript-eslint/parser
[ ] @babel/eslint-parser
[ ] vue-eslint-parser
[ ] @angular-eslint/template-parser
[ ] Other

Please show your full configuration:

Configuration

export default [];

What did you do? Please include the actual source code causing the issue.

/*eslint func-style: ["error", "declaration"]*/

class C {
    print() {
        console.log("I'm print of C");
    }
}

class D extends C {
    print() {
        console.log("I'm print of D");
    }

    test() {
        const arr1 = () => { // allowed
            this.print();
        }
        const arr2 = () => { // reported, false positive
            super.print();
        }

        arr1(); // logs "I'm print of D"
        arr2(); // logs "I'm print of C"
    }
}

new D().test();

What did you expect to happen?

No lint errors from func-style, because arr1 and arr2 cannot be replaced with function declarations.

What actually happened? Please include the actual, raw output from ESLint.

Error on arr2:

  18:15  error  Expected a function declaration  func-style

What changes did you make? (Give an overview)

Updated func-style rule to treat super the same as this.

Is there anything you'd like reviewers to focus on?

[netlify]

✅ Deploy Preview for docs-eslint canceled.

Name	Link
🔨 Latest commit	3c214b5
🔍 Latest deploy log	https://app.netlify.com/sites/docs-eslint/deploys/6648bea8daa002000860972c

[fasttime]

LGTM, thanks! Leaving open until the current release issue #18424 is closed.