lib/rules/no-mixed-operators.js
function includesBothInAGroup(groups, left, right) {
    return groups.some(group => group.indexOf(left) !== -1 && group.indexOf(right) !== -1);
}
function includesBothInAGroup(groups, left, right) {
    return groups.some(group => group.indexOf(left) !== -1 && group.indexOf(right) !== -1);
}
function includesBothInAGroup ( groups , left , right ) { return groups . some ( group => group . indexOf ( left ) !== - 1 && group . indexOf ( right ) !== - 1 ) ; }
Checks whether any group which includes both given operator exists or not.

@param {Array.<string[]>} groups - A list of groups to check.
@param {string} left - An operator.
@param {string} right - Another operator.
@returns {boolean} `true` if such group existed.
Checks whether any group which includes both given operator exists or not .