eslint-plugin-lit/lib/rules/no-template-map.js

lit-html support for ESLint

"use strict";
/**
 * @fileoverview Disallows array `.map` in templates
 * @author James Garbutt <https://github.com/43081j>
 */
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
const rule = {
    meta: {
        docs: {
            description: 'Disallows array `.map` in templates',
            recommended: false,
            url: 'https://github.com/43081j/eslint-plugin-lit/blob/master/docs/rules/no-template-map.md'
        },
        schema: [],
        messages: {
            noMap: '`.map` is disallowed in templates, move the expression out' +
                ' of the template instead'
        }
    },
    create(context) {
        // variables should be defined here
        //----------------------------------------------------------------------
        // Helpers
        //----------------------------------------------------------------------
        //----------------------------------------------------------------------
        // Public
        //----------------------------------------------------------------------
        return {
            TaggedTemplateExpression: (node) => {
                if (node.type === 'TaggedTemplateExpression' &&
                    node.tag.type === 'Identifier' &&
                    node.tag.name === 'html') {
                    for (const expr of node.quasi.expressions) {
                        if (expr.type === 'CallExpression' &&
                            expr.callee.type === 'MemberExpression' &&
                            expr.callee.property.type === 'Identifier' &&
                            expr.callee.property.name === 'map') {
                            context.report({
                                node: expr,
                                messageId: 'noMap'
                            });
                        }
                    }
                }
            }
        };
    }
};
module.exports = rule;