@lucivpav I just ran into this issue too.
I found a solution for this -

this should be

varstrExpr=expr.toString();if(strExpr[0]==='{'||strExpr[strExpr.length-1]==='}'){expr=['(',expr,')'];}

I'm pretty sure the last character cannot be part of the comment, in that case the comment would not be part of the node

I wonder if this fix works for the affected parenthesized expressions in general, or just in function bodies 🤔

@lucivpav a better solution is to check the node types:

if(node.type===Syntax.ArrowFunctionExpression&&node.body.type===Syntax.ObjectExpression){expr=['(',expr,')'];}

@lucivpav This PR does not cover this scenario:
var a = b => ({}.hasOwnProperty.call(b, "c"));
This is a CallExpression and not an ObjectExpression.
Maybe it should be simply:
if (node.type === Syntax.ArrowFunctionExpression) { expr = ['(', expr, ')']; }

@Itazulay my new PR is implementing it properly IMO
https://github.com/estools/escodegen/pull/437/files#diff-f422139858ace4feaa93c12eac40aff386df95122af5cf2fc1874bf946ef8578R294