什么是一个很好的独立JavaScript格式化程序来修复丢失的分号？

Question

I'm trying to retrofit/fix lots of legacy web code and unfortunately most of it is poorly formatted JavaScript. I'm looking for a batch/scriptable utility that can fix JavaScript that is missing simicolons at the end of executable statements.

I've tried the beautify-cl.js script with Rhino but that does not does not add semicolons. In addition, I have tried JSTidy thinking I could modify it to be scriptable, but it strips all comments. Considering we have something like 2000-3000 files, any solution has to be scriptable.

The following topics were referenced, however none of the solutions were sufficient for various reasons: Javascript Beautifier - Doesn't handle semicolon Best source code formatter for Javascript? - Not scriptable

Any ideas/solutions? Thanks in advance.

Answer 1

Obviously you'll need to do this if you want to minify the files on deployment. Missing semicolons are probably the #1 reason JS files don't minify properly, so I understand your motivation.

Write a little Python (or whatever) script to run the file through jslint, then use the output from jslint to see which lines need semicolons, then spin through the js source and add them.

I think you can be fairly fearless here, because JavaScript implicitly adds the semicolons anyway.

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Update: This set of tools may be what you are looking for . The "format" tab offers missing semicolon insertion.

Answer 2

I've found a winning combination in js-beautify and Google's Closure Linter :

# legacy.js is your poorly formatted JavaScript file, and will be modified in-place
js-beautify -s 2 -n -b end-expand -x -r legacy.js && fixjsstyle legacy.js

Explanation of js-beautify options:

• -s 2 : indent with two spaces
• -n : ensure newline at end of file
• -b end-expand : puts { braces at the end of the line, but always gives } braces their own line.
• -x : unescape \\xNN -escaped characters in strings
• -r : make changes in-place

fixjsstyle , which is installed with the Closure Linter suite, makes changes in-place by default.

This pipeline retains comments (!), indents everything (mostly) how I like, adds semicolons where appropriate, and even changes double quotes to single quotes where feasible. Both commands can be given a list of files (eg, **/*.js ), instead of just one.

To install the required packages on Mac OS X:

npm install -g js-beautify
brew install closure-linter

Answer 3

If you use JavaScript Utlity V2 at http://jsutility.pjoneil.net and use the formatting function, it will automatically replace missing semicolons.

In addition, if you use the compaction function, it will also replace missing semicolons so that the compaction will not cause any errors.

Answer 4

You shouldn't be worried about doing a mass update on a lot of legacy code for the sole purpose of inserting semi colons. That's a classic case of "doing it wrong".

How would you test the results? How would you ensure no "functionality" (as a side effect of a bug caused by a semi colon being missing) isn't lost?

What do you think adding semi colons to all these files will get you? Beside larger files (I'm not knocking the use of semicolons) and massive amounts of untested code changes?

As gumbo said, use jslint . I would use it on the files as you edit them in your day to day work. As you edit these files, presumably you will be testing changes to the file at that time. That would be the most ideal time to go crazy with semi colon insertion.

Also, if you're concerned about keeping 2000-3000 legacy javascript files alive and supported, you've got far bigger problems than semi colons

Answer 5

如果http://jsutility.pjoneil.net丢失了太多错误（并且无法对其进行格式化），您可以尝试使用以下命令对其进行压缩： http ： //refresh-sf.com/yui/ （这将添加缺少的分号）然后返回到pjoneil.net格式化程序，以分号获取漂亮的代码。