add resetDefaultValueLocale option

README.md

@@ -196,7 +196,7 @@ module.exports = {
   failOnWarnings: false,
   // Exit with an exit code of 1 on warnings
 
-  customValueTemplate: null
+  customValueTemplate: null,
   // If you wish to customize the value output the value as an object, you can set your own format.
   // ${defaultValue} is the default value you set in your translation function.
   // Any other custom property will be automatically extracted.
@@ -206,6 +206,12 @@ module.exports = {
   //   message: "${defaultValue}",
   //   description: "${maxLength}", // t('my-key', {maxLength: 150})
   // }
+
+  resetDefaultValueLocale: null
+  // The locale to compare with default values to determine whether a default value has been changed.
+  // If this is set and a default value differs from a translation in the specified locale, all entries
+  // for that key across locales are reset to the default value, and existing translations are moved to
+  // the `_old` file.
 }
 ```
 

src/helpers.js

@@ -118,19 +118,22 @@ function dotPathToHash(entry, target = {}, options = {}) {
  * Takes a `source` hash and makes sure its value
  * is pasted in the `target` hash, if the target
  * hash has the corresponding key (or if `options.keepRemoved` is true).
- * @returns An `{ old, new, mergeCount, pullCount, oldCount }` object.
+ * @returns An `{ old, new, mergeCount, pullCount, oldCount, reset, resetCount }` object.
  * `old` is a hash of values that have not been merged into `target`.
  * `new` is `target`. `mergeCount` is the number of keys merged into
  * `new`, `pullCount` is the number of context and plural keys added to
  * `new` and `oldCount` is the number of keys that were either added to `old` or
  * `new` (if `options.keepRemoved` is true and `target` didn't have the corresponding
- * key).
+ * key) and `reset` is the keys that were reset due to not matching default values,
+ *  and `resetCount` which is the number of keys reset.
  */
-function mergeHashes(source, target, options = {}) {
+function mergeHashes(source, target, options = {}, resetValues = {}) {
   let old = {}
+  let reset = {}
   let mergeCount = 0
   let pullCount = 0
   let oldCount = 0
+  let resetCount = 0
 
   const keepRemoved = options.keepRemoved || false
   const pluralSeparator = options.pluralSeparator || '_'
@@ -148,12 +151,25 @@ function mergeHashes(source, target, options = {}) {
         old[key] = nested.old
       }
     } else if (target[key] !== undefined) {
-      if (typeof source[key] === 'string' || Array.isArray(source[key])) {
-        target[key] = source[key]
-        mergeCount += 1
-      } else {
+      if (typeof source[key] !== 'string' && !Array.isArray(source[key])) {
         old[key] = source[key]
         oldCount += 1
+      } else {
+        if (
+          (options.resetAndFlag &&
+            !isPlural(key) &&
+            typeof source[key] === 'string' &&
+            source[key] !== target[key]) ||
+          resetValues[key]
+        ) {
+          old[key] = source[key]
+          oldCount += 1
+          reset[key] = true
+          resetCount += 1
+        } else {
+          target[key] = source[key]
+          mergeCount += 1
+        }
       }
     } else {
       // support for plural in keys
@@ -183,7 +199,15 @@ function mergeHashes(source, target, options = {}) {
     }
   }
 
-  return { old, new: target, mergeCount, pullCount, oldCount }
+  return {
+    old,
+    new: target,
+    mergeCount,
+    pullCount,
+    oldCount,
+    reset,
+    resetCount,
+  }
 }
 
 /**
@@ -205,9 +229,16 @@ function transferValues(source, target) {
   }
 }
 
+const pluralSuffixes = ['zero', 'one', 'two', 'few', 'many', 'other']
+
+function isPlural(key) {
+  return pluralSuffixes.some((suffix) => key.endsWith(suffix))
+}
+
 function hasRelatedPluralKey(rawKey, source) {
-  const suffixes = ['zero', 'one', 'two', 'few', 'many', 'other']
-  return suffixes.some((suffix) => source[`${rawKey}${suffix}`] !== undefined)
+  return pluralSuffixes.some(
+    (suffix) => source[`${rawKey}${suffix}`] !== undefined
+  )
 }
 
 function getSingularForm(key, pluralSeparator) {
@@ -219,10 +250,8 @@ function getSingularForm(key, pluralSeparator) {
 }
 
 function getPluralSuffixPosition(key) {
-  const suffixes = ['zero', 'one', 'two', 'few', 'many', 'other']
-
-  for (let i = 0, len = suffixes.length; i < len; i++) {
-    if (key.endsWith(suffixes[i])) return i
+  for (let i = 0, len = pluralSuffixes.length; i < len; i++) {
+    if (key.endsWith(pluralSuffixes[i])) return i
   }
 
   return -1

src/transform.js

@@ -33,6 +33,7 @@ export default class i18nTransform extends Transform {
       namespaceSeparator: ':',
       pluralSeparator: '_',
       output: 'locales/$LOCALE/$NAMESPACE.json',
+      resetDefaultValueLocale: null,
       sort: false,
       useKeysAsDefaultValue: false,
       verbose: false,
@@ -125,8 +126,20 @@ export default class i18nTransform extends Transform {
   }
 
   _flush(done) {
-    for (const locale of this.options.locales) {
+    let maybeSortedLocales = this.options.locales
+    if (this.options.resetDefaultValueLocale) {
+      // ensure we process the reset locale first
+      maybeSortedLocales.sort((a) =>
+        a === this.options.resetDefaultValueLocale ? -1 : 1
+      )
+    }
+
+    // Tracks keys to reset by namespace
+    let resetValues = {}
+
+    for (const locale of maybeSortedLocales) {
       const catalog = {}
+      const resetAndFlag = this.options.resetDefaultValueLocale === locale
 
       let countWithPlurals = 0
       let uniqueCount = this.entries.length
@@ -193,7 +206,23 @@ export default class i18nTransform extends Transform {
           old: oldKeys,
           mergeCount,
           oldCount,
-        } = mergeHashes(existingCatalog, catalog[namespace], this.options)
+          reset: resetFlags,
+          resetCount,
+        } = mergeHashes(
+          existingCatalog,
+          catalog[namespace],
+          {
+            ...this.options,
+            resetAndFlag,
+          },
+          resetValues[namespace]
+        )
+
+        // record values to be reset
+        // assumes that the 'default' namespace is processed first
+        if (resetAndFlag && !resetValues[namespace]) {
+          resetValues[namespace] = resetFlags
+        }
 
         // restore old translations
         const { old: oldCatalog, mergeCount: restoreCount } = mergeHashes(
@@ -218,6 +247,9 @@ export default class i18nTransform extends Transform {
           } else {
             console.log(`Removed keys: ${oldCount}`)
           }
+          if (this.options.resetDefaultValueLocale) {
+            console.log(`Reset keys: ${resetCount}`)
+          }
           console.log()
         }
 

test/helpers/mergeHashes.test.js

@@ -228,4 +228,40 @@ describe('mergeHashes helper function', () => {
     assert.strictEqual(res.oldCount, 0)
     done()
   })
+
+  it('resets keys to the target value if they are flagged in the resetKeys object', (done) => {
+    const source = { key1: 'key1', key2: 'key2' }
+    const target = { key1: 'changedKey1', key2: 'changedKey2' }
+    const res = mergeHashes(source, target, {}, { key1: true })
+
+    assert.deepEqual(res.new, { key1: 'changedKey1', key2: 'key2' })
+    assert.deepEqual(res.old, { key1: 'key1' })
+    assert.strictEqual(res.resetCount, 1)
+    done()
+  })
+
+  it('ignores keys if they are plurals', (done) => {
+    const source = { key1_one: 'key1', key2: 'key2' }
+    const target = { key1_one: 'changedKey1', key2: 'changedKey2' }
+    const res = mergeHashes(source, target, {}, { key1: true })
+
+    assert.deepEqual(res.new, { key1_one: 'key1', key2: 'key2' })
+    assert.deepEqual(res.old, {})
+    assert.strictEqual(res.resetCount, 0)
+    done()
+  })
+
+  it('resets and flags keys if the resetAndFlag value is set', (done) => {
+    const source = { key1: 'key1', key2: 'key2' }
+    const target = { key1: 'changedKey1', key2: 'key2' }
+    const res = mergeHashes(source, target, {
+      resetAndFlag: true,
+    })
+
+    assert.deepEqual(res.new, { key1: 'changedKey1', key2: 'key2' })
+    assert.deepEqual(res.old, { key1: 'key1' })
+    assert.deepEqual(res.reset, { key1: true })
+    assert.strictEqual(res.resetCount, 1)
+    done()
+  })
 })

test/locales/ar/test_reset.json

@@ -0,0 +1,3 @@
+{
+  "key": "ar_translation"
+}

test/locales/en/test_reset.json

@@ -0,0 +1,3 @@
+{
+  "key": "en_translation"
+}

test/locales/fr/test_reset.json

@@ -0,0 +1,3 @@
+{
+  "key": "defaultTranslation"
+}

test/parser.test.js

@@ -1,8 +1,9 @@
-import { assert } from 'chai'
+import { assert, expect } from 'chai'
 import Vinyl from 'vinyl'
 import fs from 'fs'
 import i18nTransform from '../src/transform'
 import path from 'path'
+import sinon from 'sinon'
 
 const enLibraryPath = path.normalize('en/translation.json')
 const arLibraryPath = path.normalize('ar/translation.json')
@@ -661,6 +662,129 @@ describe('parser', () => {
   })
 
   describe('options', () => {
+    describe('resetDefaultValueLocale', () => {
+      it('will not reset a key if a default value has not changed in the locale', (done) => {
+        const i18nextParser = new i18nTransform({
+          resetDefaultValueLocale: 'fr',
+          output: 'test/locales/$LOCALE/$NAMESPACE.json',
+          locales: ['en', 'ar', 'fr'],
+        })
+
+        const fakeFile = new Vinyl({
+          contents: Buffer.from(
+            `t('test_reset:key', {
+            defaultValue: 'defaultTranslation',
+          })`
+          ),
+          path: 'file.js',
+        })
+
+        let enResult, arResult
+        i18nextParser.on('data', (file) => {
+          if (file.relative.endsWith(path.normalize('en/test_reset.json'))) {
+            enResult = JSON.parse(file.contents)
+          } else if (
+            file.relative.endsWith(path.normalize('ar/test_reset.json'))
+          ) {
+            arResult = JSON.parse(file.contents)
+          }
+        })
+        i18nextParser.once('end', () => {
+          assert.deepEqual(enResult, {
+            key: 'en_translation',
+          })
+          assert.deepEqual(arResult, {
+            key: 'ar_translation',
+          })
+          done()
+        })
+
+        i18nextParser.end(fakeFile)
+      })
+
+      it('will reset a key if a default value has changed in the locale', (done) => {
+        const i18nextParser = new i18nTransform({
+          resetDefaultValueLocale: 'fr',
+          output: 'test/locales/$LOCALE/$NAMESPACE.json',
+          locales: ['en', 'ar', 'fr'],
+        })
+
+        const newString = 'newTranslation'
+
+        const fakeFile = new Vinyl({
+          contents: Buffer.from(
+            `t('test_reset:key', {
+            defaultValue: '${newString}',
+          })`
+          ),
+          path: 'file.js',
+        })
+
+        let enResult, arResult
+        i18nextParser.on('data', (file) => {
+          if (file.relative.endsWith(path.normalize('en/test_reset.json'))) {
+            enResult = JSON.parse(file.contents)
+          } else if (
+            file.relative.endsWith(path.normalize('ar/test_reset.json'))
+          ) {
+            arResult = JSON.parse(file.contents)
+          }
+        })
+        i18nextParser.once('end', () => {
+          assert.deepEqual(enResult, {
+            key: newString,
+          })
+          assert.deepEqual(arResult, {
+            key: newString,
+          })
+          done()
+        })
+
+        i18nextParser.end(fakeFile)
+      })
+    })
+
+    describe('verbose', () => {
+      beforeEach(() => {
+        sinon.spy(console, 'log')
+      })
+
+      afterEach(() => {
+        console.log.restore();
+      })
+
+      describe('with defaultResetLocale', () => {
+        it('logs the number of values reset', (done) => {
+          const i18nextParser = new i18nTransform({
+            verbose: true,
+            resetDefaultValueLocale: 'fr',
+            output: 'test/locales/$LOCALE/$NAMESPACE.json',
+            locales: ['en', 'fr'],
+          })
+
+          const newString = 'newTranslation'
+
+          const fakeFile = new Vinyl({
+            contents: Buffer.from(
+              `t('test_reset:key', {
+              defaultValue: '${newString}',
+            })`
+            ),
+            path: 'file.js',
+          })
+
+          i18nextParser.on('data', () => {})
+
+          i18nextParser.once('end', () => {
+            assert(console.log.calledWith('Reset keys: 1'))
+            done()
+          })
+
+          i18nextParser.end(fakeFile)
+        })
+      })
+    })
+
     it('handles output with $LOCALE and $NAMESPACE var', (done) => {
       let result
       const i18nextParser = new i18nTransform({