findUnusedTranslations.js

/*
This script *tries* to find unused tranlations. :)
Do not expect 100% perfect detection, but it should give good enough results.

This script can detect:
```
t('some_translation_key') // can be detected
let x: TranslationKey = "some_translation_key" // can be detected, because of the use of `t()`
let x = "some_translation_key" as TranslationKey // can be detected, because of the use of TranslationKey
<Trans i18nKey="some_translation_key"` /> can be detected, because of the use of prop i18nKey
```

This script cannot detect:
```
{message: "some_translation_key"} // cannot be detected.
```
A way to solve it is to use the `as TranslationKey`
```
{message: "some_translation_key" as TranslationKey} // can be detected, because of the use of TranslationKey
```

You can tweak the linePatternsThatMayContainTranslations to extend the detection of lines with translations.
You can twaek the ignoreTranslations to ignore some translations.
*/

/**
 * Regex patterns that should detect a translation key.
 * Specify them here:
 */
const linePatternsThatMayContainTranslations = [
  /.*t\(.*/, // should find `{t('some_key')}` or `i18n.t('some_key')` calls
  /.*TranslationKey.*/, // should find `message: "some_key" as TranslationKey` or `let title: TranslationKey = "some_key"`
  /.*i18nKey.*/ // should find `<Trans i18nKey="diversity_page.openness.effects"`
]

/**
 * There are some translations that shuold be ignored.
 * Specify them here:
 */
const ignoreTranslations = [
  /^enums/, // dynamically generated
  /^hello_processing\.error_code/, // dynamically generated
  /^hello_processing\.error_code/, // dynamically generated
  /^assessment_detail\..*\.title/, // dynamically generated
  /^assessment_detail\..*\.low/, // dynamically generated
  /^assessment_detail\..*\.mid/, // dynamically generated
  /^assessment_detail\..*\.high/, // dynamically generated
  /^hello_results_page.populations/, // dynamically generated
  /^video_recording.color_scheme/, // dynamically generated
  /^hellovima.error_codes/, // dynamically generated
  /^video_recording.fields_type.enum/, // dynamically generated
]

// --- You should not be interested in the bellow, but you can take a look.
const path = require('path');
var findInFiles = require("find-in-files")

const targetDir = path.join(__dirname, '..', 'src')
const targetFiles = "(.ts|.tsx|.js|.jsx)$"

const allTranslationKeys = Object.keys(require("../src/i18n/locales/en.json"))
const notIgnoredTranslationKeys = allTranslationKeys.filter(translationKey => !isIgnored(translationKey))

/**
 * Ignore thanslations that are dynamically generated like `t{`some_key.{dynamicValue}`}`
 * @param      {string}  translationKey   The value
 * @return     {boolean}  { description_of_the_return_value }
 */
function isIgnored(translationKey) {
  return ignoreTranslations.some(ignoredTraslationRegex => ignoredTraslationRegex.test(translationKey))
}

async function main() {
  const linesThatMaybeContainTranslations = []

  for (const pattern of linePatternsThatMayContainTranslations) {
    const results = await findInFiles.find(pattern, targetDir, targetFiles)
    const linesWithTranslations = extractLinesFromResults(results)
    linesThatMaybeContainTranslations.push(...linesWithTranslations)
  }

  const unusedKeys = notIgnoredTranslationKeys.filter(translationKey => {
    return !linesThatMaybeContainTranslations.some(line => line.includes(translationKey))
  })

  console.log(`Found ${unusedKeys.length} unused keys:`)
  console.log(unusedKeys)
}

main()

/**
 * @param      {Results}  results  The results
 * @return     {string[]}   The used translations.
 */
function extractLinesFromResults(results) {
  /** @type {string[]} */
  let usedTranslations = []

  for (const fileName in results) {
    const result = results[fileName]
    usedTranslations = usedTranslations.concat(result.matches)
  }
  return usedTranslations
}

Did you install the find-in-files dependency?

Package.json

{
  "scripts": {
    "find-unused-translations": "node ./scripts/findUnusedTranslations.js"
  },
  "devDependencies": {
    "find-in-files": "^0.5.0",
  }
}

yes i put this one in json file
but my question is how run wich one command

node

?

or

yarn run

or

npx?