Add ESLint Travis task

[ghost]

Note that this doesn't include any ESLint rules and ESLint will always succeed until we'll add the rules. I will create 3 more PRs with different ESLint rules: Standard, Airbnb and Google.

[ghost]

ping @Hainish

[Hainish]

We've generally put tools like this in utils/

[ghost]

@Hainish It is in /test/.

[Hainish]

I mean https://github.com/koops76/https-everywhere/blob/725aaa538e85dfc2fb695d63e79a81ca1a296a14/chromium/package.json

[ghost]

@Hainish Or do you want ESLint to be installed under /utils/? Usually dev dependencies are installed under node-modules, just like regular dependencies.

[ghost]

@Hainish Yeah, package.json is supposed to be in /chromium/. It's not an utility.

[ghost]

@Hainish https://docs.npmjs.com/files/package.json

[ghost]

@Hainish Also, node_modules, .gitignore, .eslintrc.json and package.json should be excluded from the crx, just in case.

[ghost]

@Hainish How can I exclude a file or a directory from the crx?

[Hainish]

This is a utility run over the chromium/ codebase. If there are other utilities added in the future, they would also need to be in their own separate paths in utils/. This is necessary to keep the repo tidy, not just throwing a package.json in the chromium/ codebase for this particular use case.

[ghost]

@Hainish We may need package.json later, when we will be adding unit tests ran in Node environment using a test runner like Mocha, but OK, I will remove it for now.

[ghost]

@Hainish Done.

[ghost]

@Hainish Ready for merge.

[Hainish]

@koops76 for some reason, the eslnit run isn't working as intended. Even with a junk commit in #10899, the eslint test passes: https://travis-ci.org/EFForg/https-everywhere/jobs/250977450

[ghost]

@Hainish Of course. There are no rules set up to lint against.

[Hainish]

@koops76 this was properly failing previously, before moving to utils/

[ghost]

@Hainish Try now.

[ghost]

@Hainish It works.
https://travis-ci.org/EFForg/https-everywhere/jobs/250990887
https://travis-ci.org/EFForg/https-everywhere/jobs/250991973