eslint-plugin-svelte/lib/rules/experimental-require-slot-types.js

ESLint plugin for Svelte using AST

import { createRule } from '../utils/index.js';
import { getLangValue } from '../utils/ast-utils.js';
const SLOTS_TYPE_NAME = '$$Slots';
export default createRule('experimental-require-slot-types', {
    meta: {
        docs: {
            description: 'require slot type declaration using the `$$Slots` interface',
            category: 'Experimental',
            recommended: false
        },
        schema: [],
        messages: {
            missingSlotsInterface: `The component must define the $$Slots interface.`
        },
        type: 'suggestion'
    },
    create(context) {
        let isTs = false;
        let hasSlot = false;
        let hasDeclaredSlots = false;
        return {
            SvelteScriptElement(node) {
                const lang = getLangValue(node)?.toLowerCase();
                isTs = lang === 'ts' || lang === 'typescript';
            },
            SvelteElement(node) {
                if (node.name.type === 'SvelteName' && node.name.name === 'slot') {
                    hasSlot = true;
                }
            },
            TSInterfaceDeclaration(node) {
                if (node.id.name === SLOTS_TYPE_NAME) {
                    hasDeclaredSlots = true;
                }
            },
            TSTypeAliasDeclaration(node) {
                if (node.id.name === SLOTS_TYPE_NAME) {
                    hasDeclaredSlots = true;
                }
            },
            'Program:exit'() {
                if (isTs && hasSlot && !hasDeclaredSlots) {
                    context.report({
                        loc: {
                            line: 1,
                            column: 1
                        },
                        messageId: 'missingSlotsInterface'
                    });
                }
            }
        };
    }
});