simple i18n based on yaml

i18n-extract.ts

import { existsSync, mkdirSync, readFileSync, writeFileSync } from 'fs'
import { dirname, join } from 'path'
import { glob } from 'glob'
import yaml from 'js-yaml'

interface TranslationEntry {
  key: string
  files: string[]
}

// Extract t`...` template strings from file content
function extractTranslations(
  content: string,
  filePath: string,
): TranslationEntry[] {
  const translations: TranslationEntry[] = []

  // Regex to match t`...` template strings
  // This handles single-line and multi-line template strings
  const regex = /\bt`([^`]+)`/g
  let match
  while ((match = regex.exec(content)) !== null) {
    const key = match[1]
    translations.push({
      key,
      files: [filePath],
    })
  }

  return translations
}

// Merge translations from multiple files
function mergeTranslations(
  allTranslations: TranslationEntry[],
): Map<string, string[]> {
  const merged = new Map<string, string[]>()

  for (const entry of allTranslations) {
    const existing = merged.get(entry.key) || []
    merged.set(entry.key, [...existing, ...entry.files])
  }

  return merged
}

// Load existing translations from YAML
function loadExistingTranslations(locale: string): Record<string, string> {
  const filePath = join('src', 'i18n', `${locale}.yaml`)

  if (!existsSync(filePath)) {
    return {}
  }

  const content = readFileSync(filePath, 'utf-8')

  try {
    const data = yaml.load(content) as Record<string, string>
    return data || {}
  } catch (error) {
    console.error(`Error parsing ${filePath}:`, error)
    return {}
  }
}

// Generate translation YAML file
function generateTranslationFile(
  translations: Map<string, string[]>,
  existing: Record<string, string>,
): string {
  const translationObject: Record<string, string> = {}

  // Do not sort keys (newer keys come to the last)
  const keys = Array.from(translations.keys())

  for (const key of keys) {
    translationObject[key] = existing[key] || ''
  }

  const rawYaml = yaml.dump(translationObject, {
    lineWidth: -1, // Disable line wrapping
    quotingType: '"', // Use double quotes
    forceQuotes: false, // Only quote when necessary
    sortKeys: false, // Keep our sorted order
  })
  return rawYaml.replace(/""/, '|\n') // Replace empty string into newline for readability
}

async function main() {
  console.log('Extracting i18n strings...')

  // Find all .ts, .tsx, and .astro files under src/
  const files = await glob('src/**/*.{ts,tsx,astro}', {
    ignore: ['src/i18n/*.ts', 'src/i18n/*.yaml'], // Ignore translation files
  })

  console.log(`Found ${files.length} files to process`)

  const allTranslations: TranslationEntry[] = []

  // Extract translations from each file
  for (const file of files) {
    const content = readFileSync(file, 'utf-8')
    const translations = extractTranslations(content, file)
    if (translations.length > 0) {
      console.log(`Found ${translations.length} translations in ${file}`)
      allTranslations.push(...translations)
    }
  }

  // Merge translations
  const mergedTranslations = mergeTranslations(allTranslations)
  console.log(`Total unique translations: ${mergedTranslations.size}`)

  // Generate translation files for each locale
  const locales = ['ja'] // Add more locales as needed

  for (const locale of locales) {
    const existing = loadExistingTranslations(locale)
    const content = generateTranslationFile(mergedTranslations, existing)
    const outputPath = join('src', 'i18n', `${locale}.yaml`)

    // Ensure directory exists
    const dir = dirname(outputPath)
    if (!existsSync(dir)) {
      mkdirSync(dir, { recursive: true })
    }

    writeFileSync(outputPath, content)
    console.log(`Generated ${outputPath}`)

    // Report missing translations
    const missingCount = Array.from(mergedTranslations.keys()).filter(
      (key) => !existing[key] || existing[key] === '',
    ).length

    if (missingCount > 0) {
      console.log(`⚠️  ${missingCount} missing translations in ${locale}`)
    }
  }

  console.log('Done!')
}

// Run the script
main().catch(console.error)

ja.yaml

To get started, open the src/pages directory in your project.: |
  開始するには、 src/pages フォルダを編集してください
What's New in Astro 5.0?: |
  Astro 5.0 での変更点
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