eslint-plugin-green/dist/rules/memory/avoidMemoryLeaks.js

ESLint plugin for evaluating and promoting green coding practices

"use strict";
const rule = {
    meta: {
        type: 'problem',
        docs: {
            description: 'Detect potential memory leaks in event listeners and timers',
            category: 'Memory',
            recommended: true,
        },
        schema: [], // no options
    },
    create(context) {
        let hasEventListener = false;
        let hasRemoveListener = false;
        return {
            CallExpression(node) {
                if (node.callee.type === 'MemberExpression') {
                    const callee = node.callee;
                    if (callee.property.type === 'Identifier') {
                        const methodName = callee.property.name;
                        // Check for event listener additions
                        if (methodName === 'addEventListener') {
                            hasEventListener = true;
                        }
                        // Check for event listener removals
                        if (methodName === 'removeEventListener') {
                            hasRemoveListener = true;
                        }
                        // Check for setInterval without clearInterval
                        if (methodName === 'setInterval') {
                            context.report({
                                node,
                                message: 'Make sure to clear intervals when they are no longer needed to prevent memory leaks'
                            });
                        }
                    }
                }
            },
            'Program:exit'() {
                // Report if event listeners are added but not removed
                if (hasEventListener && !hasRemoveListener) {
                    context.report({
                        loc: { line: 1, column: 0 },
                        message: 'Event listeners should be removed when no longer needed to prevent memory leaks'
                    });
                }
            }
        };
    }
};
module.exports = rule;