Can I inert inline `commentBlock` before an argument?

[cimak]

I have:

f('foo');

and I want to insert inline block comment, like this:

f(/* comment */'foo');

Unfortunately, Im always getting newline between comment and argument:

// arg.comments = [ j.commentBlock(` comment `) ];
f(/* comment */
'foo');

// arg.comments = [ j.commentBlock(` comment `, true, false) ];
f(/* comment */
'foo');

// arg.comments = [ j.commentBlock(` comment `, false, true) ];
f('foo'/* comment */);

Any Ideas?

Playground:
https://astexplorer.net/#/gist/efea82bb2a028629e17f70a97e43a355/9d951cc12f51086f315d6772443c603dfb020aa4

Transformer:

export default function transformer(file: FileInfo, api: API) {
    const j = api.jscodeshift
    const root = j(file.source);
    
    root
        .find(j.CallExpression, { callee: { type: "Identifier", name: "f" } })
        .forEach((path) => {
            const arg = path.node.arguments[0];
            arg.comments = [ j.commentBlock(` comment `) ];
        });


    return root.toSource({ quote: 'single' });
}

[cimak]

well... that seems to work, but is it safe?

const comment = j.commentBlock(` comment `, true, false);
comment.loc = arg.loc; // looks hacky.

arg.comments = [ comment ];

[ElonVolo]

I think if you’re doing codemods inline comments are asking for trouble.Sent from my iPhoneOn Jun 26, 2026, at 21:21, 陈家名 ***@***.***> wrote:hiSandog left a comment (facebook/jscodeshift#688) Setting comment.loc = arg.loc may work for this printer case, but it is risky because comments with copied locations can confuse later transforms or source-map output. This might be better documented as a recast/printer limitation around inline leading comments on call arguments. A safer API-level answer would be either a printer option for preserving no-space inline block comments, or a transform pattern that replaces the argument with a raw/comment-wrapped node only when formatting fidelity is the primary goal. —Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>