Minification of `a + +a`, `x - --x`...

[acatton]

Hey @rspivak ,

I started working on this because there was a bug when minifying a + +a. It was becoming a++a which is invalid.

But I weren't very excited about how the minifying tests were done, so if you don't I added more than just fixing this bug:

• I added the ability to compare ast object. (This is the big part of the diff. I didn't want to do something generic, because in python explicit is better than generic. So I went over each ast types and added equality and __repr__)
• I didn't like how classes were monkey-patched. I felt that Metaclasses would be a better way to do that. (And this is why there were intended) so I refactored the test case creation into a big metaclasses generating the tests.
• I created tests which asserted that parse(source) == parse(minified(source))

Let me know what you think, or if you want me to change anything.

Thanks!

[acatton]

Apparently this is now unmaintained, and my fix was applied to the https://github.com/calmjs/calmjs.parse fork.

Closing.