eslint-plugin-lodash/lib/rules/prefer-reject.js

Lodash specific linting rules for ESLint

/**
 * @fileoverview Rule to check if a call to filter should be a call to reject
 */
'use strict';

/**
 * @fileoverview Rule to check if a call to filter should be a call to reject
 */
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------

module.exports = {
    meta: {
        schema: [{
            type: 'integer'
        }]
    },

    create: function create(context) {
        var _require = require('../util/lodashUtil');

        var isCallToLodashMethod = _require.isCallToLodashMethod;
        var getLodashMethodVisitors = _require.getLodashMethodVisitors;

        var _require2 = require('../util/astUtil');

        var getValueReturnedInFirstStatement = _require2.getValueReturnedInFirstStatement;
        var getFirstParamName = _require2.getFirstParamName;
        var isNegationOfMemberOf = _require2.isNegationOfMemberOf;
        var isNotEqEqToMemberOf = _require2.isNotEqEqToMemberOf;

        var _require3 = require('../util/methodDataUtil');

        var isAliasOfMethod = _require3.isAliasOfMethod;

        var DEFAULT_MAX_PROPERTY_PATH_LENGTH = 3;
        var maxLength = parseInt(context.options[0], 10) || DEFAULT_MAX_PROPERTY_PATH_LENGTH;

        function isNegativeExpressionFunction(func) {
            var returnValue = getValueReturnedInFirstStatement(func);
            var firstParamName = getFirstParamName(func);
            return isNegationOfMemberOf(returnValue, firstParamName, { maxLength: maxLength }) || isNotEqEqToMemberOf(returnValue, firstParamName, { maxLength: maxLength }) || isCallToLodashMethod(func, 'negate', context);
        }

        return getLodashMethodVisitors(context, function (node, iteratee, _ref) {
            var method = _ref.method;
            var version = _ref.version;

            if (isAliasOfMethod(version, 'filter', method) && isNegativeExpressionFunction(iteratee)) {
                context.report(node, 'Prefer _.reject over negative condition');
            }
        });
    }
};