The current implementation with `JSON.stringify()` is clever but unfortunately generates incorrect JavaScript. Using `jsesc` seems like a better and safer option. https://github.com/mathiasbynens/jsesc It doesn't have any dependencies and is pretty small.
I opted for escaping all the non ascii characters, so we don't display emojis anymore. I don't think that the world is ready yet for having random unicode characters inside of source files, there still are so many parts of the toolchain that breaks with them. If we want to revert back on this decision, there's a `minimal` option on jsesc which only escapes values that need to in order to generate valid JavaScript file (assuming the encoding of the file is set to utf8).
Also, while working on React Native, we've seen that there is an optimization inside of jsc for js files that are all ascii: it doesn't do a copy for the conversion to ucs16.
Fixes#163
This is a very handy way of playing out with prettier without having to install it. People have already been using it actively in the issues. Putting it directly inside of the repo would be better than on mine.
- This brings in the flow test suite that contains a ton of JavaScript parsing edge cases
- This creates snapshot tests using the pretty printer for all of them
- If uncomment `RUN_AST_TESTS` line in `tests/run_specs.js`, it checks ast(pretty_print(x)) == ast(x). Right now, "178 failed, 197 passed, 375 of 377 total". So half of the tests are not passing, most of them are crashes and many of the rest are subtle issues.
James Long