eslint-plugin-svelte/lib/rules/experimental-require-strict-events.js

ESLint plugin for Svelte using AST

import { createRule } from '../utils/index.js';
import { findAttribute, getLangValue } from '../utils/ast-utils.js';
const EVENTS_TYPE_NAME = '$$Events';
export default createRule('experimental-require-strict-events', {
    meta: {
        docs: {
            description: 'require the strictEvents attribute on `<script>` tags',
            category: 'Experimental',
            recommended: false
        },
        schema: [],
        messages: {
            missingStrictEvents: `The component must have the strictEvents attribute on its <script> tag or it must define the $$Events interface.`
        },
        type: 'suggestion',
        conditions: [
            {
                svelteVersions: ['3/4']
            }
        ]
    },
    create(context) {
        let isTs = false;
        let hasAttribute = false;
        let hasDeclaredEvents = false;
        let scriptNode;
        return {
            SvelteScriptElement(node) {
                const lang = getLangValue(node)?.toLowerCase();
                isTs = lang === 'ts' || lang === 'typescript';
                hasAttribute = findAttribute(node, 'strictEvents') !== null;
                scriptNode = node;
            },
            TSInterfaceDeclaration(node) {
                if (node.id.name === EVENTS_TYPE_NAME) {
                    hasDeclaredEvents = true;
                }
            },
            TSTypeAliasDeclaration(node) {
                if (node.id.name === EVENTS_TYPE_NAME) {
                    hasDeclaredEvents = true;
                }
            },
            'Program:exit'() {
                if (isTs && !hasAttribute && !hasDeclaredEvents) {
                    context.report({
                        node: scriptNode,
                        messageId: 'missingStrictEvents'
                    });
                }
            }
        };
    }
});