Fix handling of empty keys

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+# Unreleased
+
+- Add `ignoreEmptyKeys` option (default: true) to ignore empty keys when scanning source files #634
+
 # 9.3.0
 
 - Allow to use multiple translation functions with different namespaces and keyPrefixes #1083 #494 #973 #737

README.md

@@ -252,7 +252,14 @@ export default {
   // Example:
   // {
   //   lineWidth: -1,
-  // }
+
+  ignoreEmptyKeys: true,
+  // When true (default), ignores empty keys when scanning source files.
+  //
+  // This allows using t('') without adding '' to translation files or
+  // failing update checks.
+  //
+  // When false, empty keys are included in the translation files and will fail with --fail-on-update.
 }
 ```
 

index.d.ts

@@ -129,4 +129,5 @@ export interface UserConfig {
   resetDefaultValueLocale?: string | null
   i18nextOptions?: Record<string, unknown> | null
   yamlOptions?: Record<string, unknown> | null
+  ignoreEmptyKeys?: boolean
 }

src/helpers.js

@@ -32,11 +32,16 @@ function dotPathToHash(entry, target = {}, options = {}) {
     entry.keyWithNamespace.length
   )
 
-  // There is no key to process so we return an empty object
-  if (!key) {
+  // The key is empty so we return an empty object
+  if (key === '') {
     if (!target[entry.namespace]) {
       target[entry.namespace] = {}
     }
+
+    if (!options.ignoreEmptyKeys) {
+      target[entry.namespace][key] = '';
+    }
+
     return { target, duplicate, conflict }
   }
 

src/transform.js

@@ -40,6 +40,7 @@ export default class i18nTransform extends Transform {
       customValueTemplate: null,
       failOnWarnings: false,
       yamlOptions: null,
+      ignoreEmptyKeys: true,
     }
 
     this.options = { ...this.defaults, ...options }
@@ -180,6 +181,7 @@ export default class i18nTransform extends Transform {
           pluralSeparator: this.options.pluralSeparator,
           value: this.options.defaultValue,
           customValueTemplate: this.options.customValueTemplate,
+          ignoreEmptyKeys: this.options.ignoreEmptyKeys,
         })
 
         if (duplicate) {
@@ -197,6 +199,9 @@ export default class i18nTransform extends Transform {
               }`
             )
           }
+        } else if (entry.key === '' && this.options.ignoreEmptyKeys) {
+          // Ignore empty keys when scanning source files
+          // This allows using `t('')`
         } else {
           uniqueCount[entry.namespace] += 1
           if (suffix) {

test/helpers/dotPathToHash.test.js

@@ -36,15 +36,37 @@ describe('dotPathToHash helper function', () => {
   })
 
   it('handles an empty namespace', (done) => {
-    const { target, duplicate } = dotPathToHash({
-      keyWithNamespace: 'ns.',
-      namespace: 'ns',
-    })
+    const { target, duplicate } = dotPathToHash(
+      {
+        keyWithNamespace: 'ns.',
+        namespace: 'ns',
+      },
+      {},
+      {
+        ignoreEmptyKeys: true,
+      }
+    )
     assert.deepEqual(target, { ns: {} })
     assert.equal(duplicate, false)
     done()
   })
 
+  it('handles an empty namespace when ignoreEmptyKeys is false', (done) => {
+    const { target, duplicate } = dotPathToHash(
+      {
+        keyWithNamespace: 'ns.',
+        namespace: 'ns',
+      },
+      {},
+      {
+        ignoreEmptyKeys: false,
+      }
+    )
+    assert.deepEqual(target, { ns: { '': '' } })
+    assert.equal(duplicate, false)
+    done()
+  })
+
   it('handles a target hash', (done) => {
     const { target, duplicate } = dotPathToHash(
       { keyWithNamespace: 'one.two.three' },

test/parser.test.js

@@ -359,6 +359,55 @@ describe('parser', () => {
     i18nextParser.end(fakeFile)
   })
 
+  it('ignores empty keys by default', (done) => {
+    let resultContent
+    const i18nextParser = new i18nTransform({
+      locales: ['en'],
+      defaultNamespace: 'test_empty_keys',
+    })
+    const fakeFile = new Vinyl({
+      contents: Buffer.from("t('key'); t('');"),
+      path: 'file.js',
+    })
+
+    i18nextParser.on('data', (file) => {
+      if (file.relative.endsWith(path.normalize('en/test_empty_keys.json'))) {
+        resultContent = JSON.parse(file.contents)
+      }
+    })
+    i18nextParser.on('end', () => {
+      assert.deepEqual(resultContent, { key: '' })
+      done()
+    })
+
+    i18nextParser.end(fakeFile)
+  })
+
+  it('includes empty keys when ignoreEmptyKeys is false', (done) => {
+    let resultContent
+    const i18nextParser = new i18nTransform({
+      locales: ['en'],
+      defaultNamespace: 'test_ignore_empty',
+      ignoreEmptyKeys: false,
+    })
+    const fakeFile = new Vinyl({
+      contents: Buffer.from("t('key'); t('');"),
+      path: 'file.js',
+    })
+
+    i18nextParser.on('data', (file) => {
+      if (file.relative.endsWith(path.normalize('en/test_ignore_empty.json'))) {
+        resultContent = JSON.parse(file.contents)
+      }
+    })
+    i18nextParser.on('end', () => {
+      assert.deepEqual(resultContent, { key: '', '': '' })
+      done()
+    })
+
+    i18nextParser.end(fakeFile)
+  })
+
   it('applies withTranslation namespace globally', (done) => {
     let result
     const i18nextParser = new i18nTransform()