swc_ecma_codegen: missing parenthesis around IIFE results in invalid output

[maxicode2]

Describe the bug

When Compiler.print() is called with an AST consisting of an empty IIFE, the function doesn't wrap function(){} in parenthesis, causing invalid javascript to be returned.

Input code

use swc::Compiler;
use swc_ecma_ast::{CallExpr, Callee, Expr, ExprStmt, FnExpr, Function, Module, ModuleItem, Program, Stmt};

pub fn main() {
    let c = Compiler::new(Default::default());

    println!("{}", c.print(
        &Program::Module(Module {
            body: vec![
                ModuleItem::Stmt(Stmt::Expr(ExprStmt {
                    expr: Box::new(Expr::Call(CallExpr {
                        callee: Callee::Expr(Box::new(Expr::Fn(FnExpr {
                            function: Box::new(Function {
                                body: Some(Default::default()),
                                ..Default::default()
                            }),
                            ..Default::default()
                        }))),
                        ..Default::default()
                    })),
                    ..Default::default()
                }))
            ],
            ..Default::default()
        }),
        Default::default()
    ).unwrap().code);
}

Config

Playground link (or link to the minimal reproduction)

https://gist.github.com/maxicode2/35a93dcac5984fa7333af7ab491bb380

SWC Info output

No response

Expected behavior

The AST is printed as (function(){})() and node.js returns no error

Actual behavior

The AST is printed as function() {}() and node.js returns an error:

[stdin]:1
function() {}();
^^^^^^^^

SyntaxError: Function statements require a function name

Version

swc@10.0.0, swc_ecma_ast@5.0.3, swc_ecma_codegen@5.1.0

Additional context

No response

[kdy1]

Use fixer

[kdy1]

See: https://rustdoc.swc.rs/swc_core/ecma/transforms/base/fixer/fn.fixer.html

[swc-bot]

This closed issue has been automatically locked because it had no new activity for a month. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.