eslint-plugin-lodash/lib/rules/collection-method-value.js

Lodash specific linting rules for ESLint

/**
 * @fileoverview Rule to enforce usage of collection method values
 */
'use strict';

/**
 * @fileoverview Rule to enforce usage of collection method values
 */
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------

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

        var isChainBreaker = _require.isChainBreaker;
        var getLodashMethodVisitors = _require.getLodashMethodVisitors;

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

        var getMethodName = _require2.getMethodName;

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

        var getCollectionMethods = _require3.getCollectionMethods;
        var isAliasOfMethod = _require3.isAliasOfMethod;
        var getSideEffectIterationMethods = _require3.getSideEffectIterationMethods;

        var settings = require('../util/settingsUtil').getSettings(context);
        var includes = require('lodash/includes');

        function parentUsesValue(node, callType) {
            var isBeforeChainBreaker = callType === 'chained' && isChainBreaker(node.parent.parent, settings.version);
            return (isBeforeChainBreaker ? node.parent.parent : node).parent.type !== 'ExpressionStatement';
        }

        function isPureLodashCollectionMethod(method, version) {
            return includes(getCollectionMethods(version), method) && !isAliasOfMethod(version, 'remove', method);
        }

        function isSideEffectIterationMethod(method, version) {
            return includes(getSideEffectIterationMethods(version), method);
        }

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

            if (isPureLodashCollectionMethod(method, version) && !parentUsesValue(node, callType)) {
                context.report(node, 'Use value returned from _.' + method);
            } else if (isSideEffectIterationMethod(method, version) && parentUsesValue(node, callType)) {
                context.report(node, 'Do not use value returned from _.' + getMethodName(node));
            }
        });
    }
};