"SyntaxError: Unexpected identifier" thrown if traced computed property contains multi-line comments

[miluoshi]

The trace function with last argument set to true enables to enter the debugger when re-evaluating traced derivation. If we trace a computed property with it's getter function body containing a multiline comment /* */, the browser throws SyntaxError: Unexpected identifier error.

The logTraceInfo function is reponsible for injecting an anonymous function containing the debugger statement generated from a string. If we use trace to trace a computed value, the computed value's getter function body is converted into a string with derivation.derivation.toString() and then inserted into a comment of the generated function. By not escaping the generated string a multi-line comment is inserted as-is, thus early closing a comment in the generated function.

Example of generated string from the attached sandbox:

debugger;
/*
Tracing '[email protected]'

You are entering this break point because derivation '[email protected]' is being traced and '[email protected]' is now forcing it to update.
Just follow the stacktrace you should now see in the devtools to see precisely what piece of your code is causing this update
The stackframe you are looking for is at least ~6-8 stack-frames up.

get fullName() {
        /* multi-line comment */ <---------------- early closed comment
        return `${this.firstName} ${this.lastName}`;
    }

The dependencies for this derivation are:

[email protected]
	[email protected]
	[email protected]
*/

Sandbox to reproduce the issue:

https://codesandbox.io/s/v83p7xk80l

Suggested fix:

Escape (somehow) comments in the getter function's body string.
Inserting a space between closing comment tag (* /) should be enough.
derivation.derivation.toString() -> derivation.derivation.toString().replace(/\*\//g, '* /')

[mweststrate]

Confirmed! Thanks for tracking this, I think we can fix this with a simple regex.

[mweststrate]

Fixed and released in 4.9.0 / 5.9.0

[lock]

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