Skip globbing filenames with node-glob when the filename is not a glob

[hawkrives]

Closes #1246

@vjeux:

For this issue, I can see two things:

1. Use fs.readFileSync instead of going through glob is there is no special patterns. If you give the actual name of a file, we should throw if it's not there.
   […]

It turns out thatnode-glob has a handy function .hasMagic, which tells you if a given string has any globbable patterns in it. All I had to do was call it when we iterate over the filenames.

I tested this manually; I'm not sure how to add tests for the prettier cli.

# before
$ stat non-existent-file.js
stat: cannot stat 'non-existent-file.js': No such file or directory
$ prettier non-existent-file.js; echo $?
0

# after
$ stat non-existent-file.js
stat: cannot stat 'non-existent-file.js': No such file or directory
$ node bin/prettier.js non-existent-file.js; echo $?

Unable to read file: non-existent-file.js
Error: ENOENT: no such file or directory, open 'non-existent-file.js'
2

[vjeux]

You should put a return after so it doesn't also do the glob

[vjeux]

Thanks! Looks great :) If you fix the comment I'll merge it.

[hawkrives]

Done! And I added a semicolon for consistency.

[m1ck2]

You do realise that you's are swapping names and email addresses around in google and different again here.

[hawkrives]

@m1ck2 I'm sorry? Both of those commits have the same name and email, do they not?

[vjeux]

@hawkrives: I think it's a bot :( I've seen a lot of random messages like this that barely make sense on many repos across github.