ExecJS::ProgramError: SyntaxError: Unexpected token: name

Question

I've created a JavaScript class (named as BarChart) that have constructor and several methods init.

I executed below command to pre-compile assets for production environment but got error.

Command used to pre-compiling assets: rake assets:precompile RAILS_GROUPS=assets --trace

Error backtrace:

rake aborted!
ExecJS::ProgramError: SyntaxError: Unexpected token: name (BarChart) (line: 24472, col: 6, pos: 952834)

Error
    at new JS_Parse_Error (<eval>:3623:11948)
    at js_error (<eval>:3623:12167)
    at croak (<eval>:3623:22038)
    at token_error (<eval>:3623:22175)
    at unexpected (<eval>:3623:22263)
    at semicolon (<eval>:3623:22781)
    at simple_statement (<eval>:3623:25959)
    at <eval>:3623:23747
    at <eval>:3623:22954
    at <eval>:3624:3759
    at Object.parse (<eval>:3624:3999)
    at parse (<eval>:3958:22)

Javascript class which throws error is written like:

class BarChart
{
    // code goes here
}

I've added therubyracer and execjs gem in Gemfile.

Ruby: 2.2.5

Rails: 3.2.2`

PS: I've checked several questions of this type in SO, but none of the issue is related to JavaScript class.

Seems like there're two requests to close question. Can someone please explain me the reason of the **close** question request? I didn't found JS class related issue yet. — Radix, Feb 20 '17 at 13:33
I voted to close it because I do not understand it - it is unclear to me. Imagine yourself on the place of someone who has no slightest clue of your problem and describe it in a way one could understand it. The better (do not confuse with "the more") you describe the issue, the higher chances to get proper answer. — Andrey Deineko, Feb 20 '17 at 13:49
Check this link. Hope this will help you. http://www.academytimes.com/solved/7392211522/rails-5-heorku-deploy-error-execjsprogramerror-syntaxerror-unexpected-token — Code Lღver, Feb 20 '17 at 13:55
@CodeLღver Thanks for your answer but I've already checked that and it does not solve my error. — Radix, Feb 20 '17 at 13:57
@AndreyDeineko I've updated the question, please check. BTW, thanks for providing the reason for closing the question. — Radix, Feb 20 '17 at 13:58

score 1 · Answer 1 · answered May 15 '17 at 06:53

1

In your BarChart js file, change all the let to var. Then the precompile should go successfully.

answered May 15 '17 at 06:53

Liren Yeo

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score 1 · Accepted Answer · answered Jun 15 '17 at 17:22

1

I'd written the JavaScript in ES6 and rails 3 shows error while ES6 code. All the methods of using ES6 in rails is not for rails 3. So I converted ES6 to ES5 code.

answered Jun 15 '17 at 17:22

Radix

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rails, still use es5 :( – Lee Eather Feb 21 '20 at 01:45
Nope, you can use ES(6/7) syntax for rails 5 and after. – Radix Feb 24 '20 at 19:58
I could not, eg using `let` would not work. Rails 6.0.0.1. `ExecJS` compiler. – Lee Eather Feb 25 '20 at 23:45

score 1 · Answer 3 · answered Feb 22 '18 at 00:27

1

In rails 5 I resolved the issue renaming files from .js to .js.es6. Weirdly it my staging deploy worked and my production deploy did not.

answered Feb 22 '18 at 00:27

Marcelo

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ExecJS::ProgramError: SyntaxError: Unexpected token: name

3 Answers3