[Shubham-Padkonde]

Fixes #118. The function-kind regexes currently match anywhere in the source, so a concise method containing an arrow or function declaration is returned unchanged. That source is invalid in the generated object-property value and fails to deserialize.

Anchor detection to the outer function signature so concise methods still receive the existing function-expression conversion. Added round-trip cases for nested declarations, destructured arrow arguments, async methods, and generator methods. Additional cases preserve commented async signatures and arrows with function-valued defaults.

Explicitly preserve class expressions as well, including classes with and without nested arrows. A concise method named class still receives method conversion.

Validation (23 October 2026, Windows/Node 24.15.0): both new class regression tests fail before this follow-up and pass afterward; the concise-method guard passes. All 109 tests pass with node --test test/unit/*.js. git diff --check passes.

[redonkulus]

Thanks for this, and for the thorough round-trip tests. Anchoring the checks to the outer signature is the right fix for #118, and it merges cleanly onto current main with all tests passing. One regression before we can merge:

Classes now fall through to the method conversion. A class source starts with class, so it matches neither anchored regex and gets rewritten as if it were a concise method:

class A { m() { return x => x } }
serialize({ A })
// main: {"A":class A { m() { return x => x } }}      ← valid
// PR:   {"A":function(){ return x => x } }}          ← SyntaxError

(On main this only works by accident, because the unanchored arrow regex matches the nested =>. A class with no nested arrow or function, like class A { m() { return 1 } }, is already broken on main.)

Could you detect a class signature explicitly (e.g. /^class\b/ → emit the source unchanged) and add round-trip tests for both of those class cases? That would fix the regression and the existing bug together.

[redonkulus]

Thanks for the fix and the quick turnaround on the class regression! Verified against current main: all tests pass, and nested arrows/declarations in concise, async, generator and computed-key methods now round-trip correctly.