Симуляция системы tsconfig: наследование конфигов, слияние опций, валидация target/module совместимости

// Симулируем систему конфигурации TypeScript компилятора.
// Демонстрируем extends, target vs module, lib, composite.

// --- Встроенные конфиги (как @tsconfig/recommended) ---
const PRESET_CONFIGS = {
  base: {
    strict: true,
    esModuleInterop: true,
    skipLibCheck: true,
    forceConsistentCasingInFileNames: true,
    declaration: false,
  },

  'node-lts': {
    extends: 'base',
    target: 'ES2022',
    lib: ['ES2022'],
    module: 'CommonJS',
    moduleResolution: 'node',
    outDir: './dist',
  },

  'node-esm': {
    extends: 'base',
    target: 'ES2022',
    lib: ['ES2022'],
    module: 'Node16',
    moduleResolution: 'Node16',
  },

  'react-app': {
    extends: 'base',
    target: 'ES2020',
    lib: ['ES2020', 'DOM', 'DOM.Iterable'],
    module: 'ESNext',
    moduleResolution: 'bundler',
    jsx: 'react-jsx',
    sourceMap: true,
  },

  library: {
    extends: 'base',
    target: 'ES2020',
    module: 'ESNext',
    declaration: true,
    declarationMap: true,
    composite: true,
    incremental: true,
  }
}

// --- Резолвер extends ---
function resolveConfig(configName, visited = new Set()) {
  if (visited.has(configName)) {
    throw new Error(`Circular extends: ${configName}`)
  }
  visited.add(configName)

  const config = PRESET_CONFIGS[configName]
  if (!config) return {}

  if (config.extends) {
    const base = resolveConfig(config.extends, visited)
    const { extends: _, ...rest } = config
    // Merge: специфичный конфиг перекрывает базовый
    return mergeDeep(base, rest)
  }

  return { ...config }
}

function mergeDeep(base, override) {
  const result = { ...base }
  for (const [key, val] of Object.entries(override)) {
    if (Array.isArray(val) && Array.isArray(result[key])) {
      result[key] = [...new Set([...result[key], ...val])]
    } else {
      result[key] = val
    }
  }
  return result
}

// --- Валидация совместимости target/module ---
const TARGET_FEATURES = {
  'ES5': ['var', 'function', 'prototype'],
  'ES2015': ['arrow', 'class', 'let', 'const', 'Promise', 'Symbol'],
  'ES2017': ['async/await', 'Object.entries', 'Object.values'],
  'ES2020': ['optional-chaining', 'nullish-coalescing', 'BigInt'],
  'ES2022': ['top-level-await', 'class-fields', 'Array.at', 'Object.hasOwn'],
  'ESNext': ['latest-features'],
}

function getCompatibilityWarnings(config) {
  const warnings = []

  // isolatedModules несовместим с const enum
  if (config.isolatedModules && config.module !== 'CommonJS') {
    // OK
  }

  // composite требует declaration
  if (config.composite && !config.declaration) {
    warnings.push('composite: true требует declaration: true')
  }

  // DOM lib без браузерного target — необычно
  if (config.lib?.includes('DOM') && config.module === 'CommonJS') {
    warnings.push('lib: DOM с module: CommonJS — обычно это Node.js без DOM')
  }

  // incremental лучше с tsBuildInfoFile
  if (config.incremental && !config.tsBuildInfoFile) {
    warnings.push('Рекомендуется указать tsBuildInfoFile для incremental')
  }

  return warnings
}

// --- Демонстрация ---

console.log('=== Резолвинг пресетов ===')
;['node-lts', 'react-app', 'library'].forEach(preset => {
  const resolved = resolveConfig(preset)
  console.log(`\n[${preset}]`)
  console.log('  target:', resolved.target)
  console.log('  module:', resolved.module)
  console.log('  lib:', resolved.lib?.join(', ') || 'default')
  console.log('  strict:', resolved.strict)
  if (resolved.composite) console.log('  composite:', resolved.composite)
  if (resolved.jsx) console.log('  jsx:', resolved.jsx)
})

console.log('\n=== Кастомный конфиг с extends ===')
const customConfig = mergeDeep(
  resolveConfig('react-app'),
  {
    noUnusedLocals: true,
    noUnusedParameters: true,
    noImplicitReturns: true,
    baseUrl: '.',
    paths: { '@/*': ['src/*'] }
  }
)
console.log('Resolved custom config:')
console.log('  strict:', customConfig.strict)
console.log('  paths:', customConfig.paths)
console.log('  noUnusedLocals:', customConfig.noUnusedLocals)

console.log('\n=== Проверка совместимости ===')
const compositeWithoutDeclaration = { composite: true, declaration: false }
console.log('composite без declaration:', getCompatibilityWarnings(compositeWithoutDeclaration))

const nodeWithDom = { lib: ['ES2022', 'DOM'], module: 'CommonJS', composite: true, declaration: true }
console.log('Node + DOM:', getCompatibilityWarnings(nodeWithDom))

const incrementalNoFile = { incremental: true }
console.log('incremental без tsBuildInfoFile:', getCompatibilityWarnings(incrementalNoFile))