Lint improvements

[aleksuk]

1. Don't forbid to add new line inside function brakets
   refs: https://github.com/airbnb/javascript#functions--signature-invocation-indentation

As Is

const template = _.template(trans('A site requires a domain if it is published. If you wish to remove ${name}, unpublish the site.'));

Allow To Do

const template = _.template(
  trans('A site requires a domain if it is published. If you wish to remove ${name}, unpublish the site.')
);

2. Make possible to declare is already declared in the upper case variables for local scope

import {
  isAssigned,
} from 'src/ide/modules/collections/domains/compare';

const getState = (data, id) = {
  // lint says that "isAssigned" is already declared in upper scrope
  const isAssigned = data.assign;
  const isAssignedToCurrentSite = isAssigned && data.id === id;

  return { isAssigned, isAssignedToCurrentSite };
};

The same issue with react and redux with mapDispatchToProps.

import React from 'react';
import { openCustomDomainModal } from '../store/actions/action-creators';

// lint says that "openCustomDomainModal" is alreade declared in upper scrope
function MyComponent({ openCustomDomainModal }) {
  /* ... */
}
/* prop types, default props and etc */

const mapDispatchToProps = { openCustomDomainModal };
export default connect(null, mapDispatchToProps)(MyComponent);

3. Setup correct work with chai. (take a look this plugin: https://www.npmjs.com/package/eslint-plugin-chai-friendly)

// linst says `Expected an assignment or function call`
expect(onPageChange).not.to.have.been.called;

[aleksuk]

Also next issue is available with react and redux, if you don't use destructuring assignment, lint doesn't see usage of some variables, or is it correct?

function Component(/*...*/) {
/*...*/
}

Component.propTypes = {
  /* ... */
  // linst says `PropTypes is defined but prop is never used
  autoClose: PropTypes.bool,
  // linst says `PropTypes is defined but prop is never used
  onAccept: PropTypes.func,
};
// uasge of autoClose and onAccept
const mapDispatchToProps = (dispatch, ownProps) => ({
  accept() {
    const { autoClose, onAccept } = ownProps;

    onAccept();

    if (autoClose) {
      dispatch(hideModal());
    }
  },
// ...
}

export default connect(null, mapDispatchToProps)(Component);

[aleksuk]

refs: https://github.com/yola/sitebuilderui/pull/4019#discussion_r165403911

[RusinovAnton]

linst says `PropTypes is defined but prop is never used

prop isn't used within component but in the mapDispatchToProps which is in fact is outside.

There are a bunch of related issues are filled in eslint-plugin-react repo: https://github.com/yannickcr/eslint-plugin-react/issues?utf8=%E2%9C%93&q=is%3Aissue+is%3Aopen+unused+prop

There is also this ticket airbnb/javascript#1089 about overriding default rules and no-unused-prop-types is one of often overridden.

So I think this rule should be turned off in the base config for now.