Wrong error report message for expression {})

[tuannd89]

Version

v19.7.0

Platform

No response

Subsystem

No response

What steps will reproduce the bug?

$ node
> {})
({}))
    ^
Uncaught SyntaxError: Unexpected token ')'

How often does it reproduce? Is there a required condition?

Always

What is the expected behavior?

> {})
{})
    ^
Uncaught SyntaxError: Unexpected token ')'

What do you see instead?

> {})
({}))
    ^
Uncaught SyntaxError: Unexpected token ')'

Additional information

We got similar result with expression {}]

[aduh95]

Any input that starts with a { and doesn't end with a ; will be wrapped in parentheses:

node/lib/repl.js

Lines 417 to 426 in e4e8421

	// It's confusing for `{ a : 1 }` to be interpreted as a block
	// statement rather than an object literal. So, we first try
	// to wrap it in parentheses, so that it will be interpreted as
	// an expression. Note that if the above condition changes,
	// lib/internal/repl/utils.js needs to be changed to match.
	if (RegExpPrototypeExec(/^\s*{/, code) !== null &&
	RegExpPrototypeExec(/;\s*$/, code) === null) {
	code = `(${StringPrototypeTrim(code)})\n`;
	wrappedCmd = true;
	}

I think it makes sense for Node.js to show the string it tried to parse rather than the input string – and I think adding those parentheses is useful as well. So if you ask me, I'd say this is not a bug, this is a feature.

[cola119]

Potentially related issue: #46196

[jenthone]

Try to wrap input in parentheses cause another issue:

$ node
> {}),({}
{} // Expected result is Uncaught SyntaxError: Unexpected token ')'