Yii2: asset/compress needs semicolon-less JavaScripts support

[tanakahisateru]

New released yii-pjax 2.0.7 breaks my compressed JavaScript which generated by asset/compress command. JS files are joined with no separators after jquery.pjax.js.

What steps will reproduce the problem?

Create an Yii project, then simply use yii asset/compress.

What is the expected result?

At least a semicolon should be inserted. I prefer wrapping each scripts by function(){ ... }();.

What do you get instead?

Additional info

| Q | A
| ---------------- | ---
| Yii version | 2.0.12
| PHP version | 7.0.15, 7.1.8
| Operating system |Ubuntu, MacOS

[tanakahisateru]

I like semicolon but certain semicolon haters who can lead trends really exist -- GitHub, Twitter Bootstrap, Vue.js ...

[rob006]

Wrapping with (function(){ ... })(); will change code behavior - some scripts are intended to work in global scope.

[tanakahisateru]

@rob006 right! I will change my PR.

[samdark]

Isn't https://github.com/yiisoft/jquery-pjax/commit/0d4cc3f479d4b7b800aefca1275a852c8d3dd3c6 fixing the problem?

[rob006]

@samdark It will fix it for pjax, but any other library can have similar issues. Compressing assets should not depend on trailing semicolon.

[samdark]

Right. Makes sense to fix that. Would checking for trailing semicolon when concatenating files and adding it if it's not there do?

[schmunk42]

Sorry for being late to the party...

@samdark The semicolon does not hurt, but shouldn't a simple new-line be OK for this?
It's JavaScript 😏 http://www.bradoncode.com/blog/2015/08/26/javascript-semi-colon-insertion/

[edit] Hmm, not quite sure after reading this https://stackoverflow.com/a/1169596/291573

[edit2] A problematic use-case might be, that if you are passing the generated, concatenated code to another tool, it might complain about the additional semicolons.

@tanakahisateru I wonder why the comments are not visible in the screenshot above. Is the source from concatenating the files with Yii or is there another tool involved?

[samdark]

@schmunk42 I can't think of a case where it won't work as expected...

[schmunk42]

Yes, after some more research, it looks like this is the right thing to do.

• https://github.com/webpack/webpack/pull/3209/files
• https://stackoverflow.com/questions/1873983/what-does-the-leading-semicolon-in-javascript-libraries-do
• https://stackoverflow.com/a/7365214/291573
• https://stackoverflow.com/questions/20253392/add-break-line-between-files-grunt-concat
• https://github.com/github/fetch/issues/420

[tanakahisateru]

@samdark Can you reopen this issue? I found the case for trailing line comment, e.g:

(function($) {
})(jQuery) // trailing line comment 👻

... will be combined and compressed with the next file as:

/*** BEGIN FILE: 1st.js ***/
(function($) {
})(jQuery) // Trailing line comment 👻;
/*** END FILE: 1st.js  ***/
/*** BEGIN FILE: 2nd.js ***/
(function($) {
})(jQuery)
/*** END FILE: 2nd.js  ***/

↓

$ node_modules/.bin/uglifyjs conbined.js 
(function($){})(jQuery)(function($){})(jQuery);

It needs a new line before inserted semicolon.

})(jQuery) // Trailing line comment 👻
;
/*** END FILE: 1st.js  ***/

[samdark]

Would you please create a pull request? Thanks.