fix: correctly handle plurals for languages with single plural form

backend/data/src/main/kotlin/io/tolgee/formats/genericStructuredFile/in/GenericStructuredProcessor.kt

@@ -20,6 +20,7 @@ class GenericStructuredProcessor(
           context = context,
           data = data,
           pluralsViaSuffixesParser = format.pluralsViaSuffixesParser,
+          languageTag = languageTagOrGuess,
         ).preprocess()
     }
     processedData.import("")

backend/data/src/main/kotlin/io/tolgee/formats/genericStructuredFile/in/GenericStructuredRawDataToTextConvertor.kt

@@ -2,6 +2,7 @@ package io.tolgee.formats.genericStructuredFile.`in`
 
 import io.tolgee.formats.MessageConvertorResult
 import io.tolgee.formats.allPluralKeywords
+import io.tolgee.formats.getPluralFormsForLocaleOrAll
 import io.tolgee.formats.importCommon.ImportFormat
 import io.tolgee.formats.importCommon.unwrapString
 
@@ -79,7 +80,7 @@ class GenericStructuredRawDataToTextConvertor(
       return null
     }
 
-    if (map.size < 2) {
+    if (map.size < pluralKeywords.size && map.size < 2) {
       return null
     }
 
@@ -100,4 +101,8 @@ class GenericStructuredRawDataToTextConvertor(
 
     return listOf(converted)
   }
+
+  private val pluralKeywords by lazy {
+    getPluralFormsForLocaleOrAll(languageTag)
+  }
 }

backend/data/src/main/kotlin/io/tolgee/formats/genericStructuredFile/in/GenericSuffixedPluralsPreprocessor.kt

@@ -1,6 +1,7 @@
 package io.tolgee.formats.genericStructuredFile.`in`
 
 import io.tolgee.formats.allPluralKeywords
+import io.tolgee.formats.getPluralFormsForLocaleOrAll
 import io.tolgee.formats.importCommon.ParsedPluralsKey
 import io.tolgee.formats.importCommon.PluralsKeyParser
 import io.tolgee.service.dataImport.processors.FileProcessorContext
@@ -9,6 +10,7 @@ class GenericSuffixedPluralsPreprocessor(
   val context: FileProcessorContext,
   private val data: Any?,
   private val pluralsViaSuffixesParser: PluralsKeyParser,
+  private val languageTag: String,
 ) {
   fun preprocess(): Any? {
     return data.preprocess()
@@ -68,10 +70,14 @@ class GenericSuffixedPluralsPreprocessor(
 
   private fun Map<*, *>.preprocessMap(): Map<*, *> {
     return this.groupByPlurals(pluralsViaSuffixesParser).flatMap { (commonKey, values) ->
-      if (commonKey == null || values.size < 2) {
+      if (commonKey == null || (values.size < pluralKeywords.size && values.size < 2)) {
         return@flatMap values.useOriginalKey()
       }
       return@flatMap values.usePluralsKey(commonKey)
     }.toMap()
   }
+
+  private val pluralKeywords by lazy {
+    getPluralFormsForLocaleOrAll(languageTag)
+  }
 }

backend/data/src/main/kotlin/io/tolgee/formats/pluralFormsUtil.kt

@@ -16,6 +16,15 @@ val allPluralKeywords =
     PluralRules.KEYWORD_OTHER,
   )
 
+fun getPluralFormsForLocaleOrAll(languageTag: String): List<String> {
+  return try {
+    val locale = getULocaleFromTag(languageTag)
+    PluralRules.forLocale(locale)?.keywords?.toList() ?: allPluralKeywords
+  } catch (_: Exception) {
+    allPluralKeywords
+  }
+}
+
 fun getPluralFormsForLocale(languageTag: String): MutableSet<String> {
   val uLocale = getULocaleFromTag(languageTag)
   val pluralRules = PluralRules.forLocale(uLocale)