svelte.ts

import { ensurePackages, interopDefault } from '../utils'
import type { OptionsFiles, OptionsHasTypeScript, OptionsOverrides, OptionsStylistic, TypedFlatConfigItem } from '../types'
import { GLOB_SVELTE } from '../globs'

export async function svelte(
  options: OptionsHasTypeScript & OptionsOverrides & OptionsStylistic & OptionsFiles = {},
): Promise<TypedFlatConfigItem[]> {
  const {
    files = [GLOB_SVELTE],
    overrides = {},
    stylistic = true,
  } = options

  const {
    indent = 2,
    quotes = 'single',
  } = typeof stylistic === 'boolean' ? {} : stylistic

  await ensurePackages([
    'eslint-plugin-svelte',
  ])

  const [
    pluginSvelte,
    parserSvelte,
  ] = await Promise.all([
    interopDefault(import('eslint-plugin-svelte')),
    interopDefault(import('svelte-eslint-parser')),
  ] as const)

  return [
    {
      name: 'antfu/svelte/setup',
      plugins: {
        svelte: pluginSvelte,
      },
    },
    {
      files,
      languageOptions: {
        parser: parserSvelte,
        parserOptions: {
          extraFileExtensions: ['.svelte'],
          parser: options.typescript
            ? await interopDefault(import('@typescript-eslint/parser')) as any
            : null,
        },
      },
      name: 'antfu/svelte/rules',
      processor: pluginSvelte.processors['.svelte'],
      rules: {
        'import/no-mutable-exports': 'off',
        'no-undef': 'off', // incompatible with most recent (attribute-form) generic types RFC
        'no-unused-vars': ['error', {
          args: 'none',
          caughtErrors: 'none',
          ignoreRestSiblings: true,
          vars: 'all',
          varsIgnorePattern: '^(\\$\\$Props$|\\$\\$Events$|\\$\\$Slots$)',
        }],

        'svelte/comment-directive': 'error',
        'svelte/no-at-debug-tags': 'warn',
        'svelte/no-at-html-tags': 'error',
        'svelte/no-dupe-else-if-blocks': 'error',
        'svelte/no-dupe-style-properties': 'error',
        'svelte/no-dupe-use-directives': 'error',
        'svelte/no-dynamic-slot-name': 'error',
        'svelte/no-export-load-in-svelte-module-in-kit-pages': 'error',
        'svelte/no-inner-declarations': 'error',
        'svelte/no-not-function-handler': 'error',
        'svelte/no-object-in-text-mustaches': 'error',
        'svelte/no-reactive-functions': 'error',
        'svelte/no-reactive-literals': 'error',
        'svelte/no-shorthand-style-property-overrides': 'error',
        'svelte/no-unknown-style-directive-property': 'error',
        'svelte/no-unused-svelte-ignore': 'error',
        'svelte/no-useless-mustaches': 'error',
        'svelte/require-store-callbacks-use-set-param': 'error',
        'svelte/system': 'error',
        'svelte/valid-compile': 'error',
        'svelte/valid-each-key': 'error',

        'unused-imports/no-unused-vars': [
          'error',
          { args: 'after-used', argsIgnorePattern: '^_', vars: 'all', varsIgnorePattern: '^(_|\\$\\$Props$|\\$\\$Events$|\\$\\$Slots$)' },
        ],

        ...stylistic
          ? {
              'style/indent': 'off', // superseded by svelte/indent
              'style/no-trailing-spaces': 'off', // superseded by svelte/no-trailing-spaces
              'svelte/derived-has-same-inputs-outputs': 'error',
              'svelte/html-closing-bracket-spacing': 'error',
              'svelte/html-quotes': ['error', { prefer: quotes }],
              'svelte/indent': ['error', { alignAttributesVertically: true, indent }],
              'svelte/mustache-spacing': 'error',
              'svelte/no-spaces-around-equal-signs-in-attribute': 'error',
              'svelte/no-trailing-spaces': 'error',
              'svelte/spaced-html-comment': 'error',
            }
          : {},

        ...overrides,
      },
    },
  ]
}