"Extract to inner function" refactoring not available inside function expression

[OliverJAsh]

Bug Report

🔎 Search Terms

vs code quick fix refactoring code action arrow anonymous function

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about refactorings

⏯ Playground Link

N/A

💻 Code

const fn1 = () => {
    const x = 1;
    const y = x + 1;
};

const fn2 = function () {
    const x = 1;
    const y = x + 1;
};

1. Select the line that includes const y in either of the above function expressions
2. Try to find and run the "extract to inner function" refactoring

🙁 Actual behavior

The "extract to inner function" refactoring is not listed.

🙂 Expected behavior

The "extract to inner function" refactoring is listed and produces this code:

const fn1 = () => {
    const x = 1;
    const y = newFunction();

    function newFunction() {
        return x + 1;
    }
};

const fn2 = function () {
    const x = 1;
    const y = newFunction();

    function newFunction() {
        return x + 1;
    }
};

Note: ideally it would produce arrow functions but that's a separate issue: #31860

---

It seems this refactoring is only available inside of function declarations. Is there a reason for this?

function fn0() {
    const x = 1;
    const y = x + 1;
}

This produces:

function fn0() {
    const x = 1;
    const y = newFunction();

    function newFunction() {
        return x + 1;
    }
}

[OliverJAsh]

I would be happy to work on this and a few other issues related to these refactorings, but I will most likely need some guidance as I don't really know where to start nor where to find the code responsible.

[OliverJAsh]

I've started work on this here: #44206. Does it look like I'm going in the right direction?