eslint-plugin-sonarjs/lib/src/rules/non-existent-operator.js

SonarJS rules for ESLint

"use strict";
/*
 * eslint-plugin-sonarjs
 * Copyright (C) 2018-2021 SonarSource SA
 * mailto:info AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
// https://sonarsource.github.io/rspec/#/rspec/S2757
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
const docs_url_1 = __importDefault(require("../utils/docs-url"));
const rule = {
    defaultOptions: [],
    meta: {
        messages: {
            useExistingOperator: 'Was "{{operator}}=" meant instead?',
            suggestExistingOperator: 'Replace with "{{operator}}" operator',
        },
        schema: [],
        type: 'problem',
        hasSuggestions: true,
        docs: {
            description: 'Non-existent operators "=+", "=-" and "=!" should not be used',
            recommended: 'recommended',
            url: (0, docs_url_1.default)(__filename),
        },
    },
    create(context) {
        return {
            AssignmentExpression(node) {
                const assignmentExpression = node;
                if (assignmentExpression.operator === '=') {
                    checkOperator(context, assignmentExpression.right);
                }
            },
            VariableDeclarator(node) {
                const variableDeclarator = node;
                checkOperator(context, variableDeclarator.init);
            },
        };
    },
};
function checkOperator(context, unaryNode) {
    if (unaryNode &&
        unaryNode.type === 'UnaryExpression' &&
        isUnaryOperatorOfInterest(unaryNode.operator)) {
        const { sourceCode } = context;
        const assignmentOperatorToken = sourceCode.getTokenBefore(unaryNode, token => token.value === '=');
        const unaryOperatorToken = sourceCode.getFirstToken(unaryNode);
        const expressionFirstToken = sourceCode.getFirstToken(unaryNode.argument);
        if (assignmentOperatorToken != null &&
            unaryOperatorToken != null &&
            expressionFirstToken != null &&
            areAdjacent(assignmentOperatorToken, unaryOperatorToken) &&
            !areAdjacent(unaryOperatorToken, expressionFirstToken)) {
            const suggest = [];
            if (unaryNode.parent?.type === 'AssignmentExpression') {
                const range = [
                    assignmentOperatorToken.range[0],
                    unaryOperatorToken.range[1],
                ];
                const invertedOperators = unaryOperatorToken.value + assignmentOperatorToken.value;
                suggest.push({
                    messageId: 'suggestExistingOperator',
                    data: {
                        operator: invertedOperators,
                    },
                    fix: fixer => fixer.replaceTextRange(range, invertedOperators),
                });
            }
            context.report({
                messageId: 'useExistingOperator',
                data: {
                    operator: unaryNode.operator,
                },
                loc: { start: assignmentOperatorToken.loc.start, end: unaryOperatorToken.loc.end },
                suggest,
            });
        }
    }
}
function isUnaryOperatorOfInterest(operator) {
    return operator === '-' || operator === '+' || operator === '!';
}
function areAdjacent(first, second) {
    return (first.loc.end.column === second.loc.start.column && first.loc.end.line === second.loc.start.line);
}
module.exports = rule;