Fixed translation bug when the locale contained the region (#765)

* Fixed the issue, added tests and italian translation

* changelog

* improved translation handling code and added more tests

* Update UnitTests/Sources/LocalizationTests.swift

Co-authored-by: Stefan Ceriu <stefanc@matrix.org>

---------

Co-authored-by: Stefan Ceriu <stefanc@matrix.org>

Tools/SwiftGen/Templates/Strings/structured-swift5-element-untranslated.stencil

@@ -0,0 +1,92 @@
+// swiftlint:disable all
+// Generated using SwiftGen — https://github.com/SwiftGen/SwiftGen
+
+{% if tables.count > 0 %}
+{% set accessModifier %}{% if param.publicAccess %}public{% else %}internal{% endif %}{% endset %}
+import Foundation
+
+// swiftlint:disable superfluous_disable_command file_length implicit_return
+
+// MARK: - Strings
+
+{% macro parametersBlock types %}{% filter removeNewlines:"leading" %}
+  {% for type in types %}
+    {% if type == "String" %}
+    _ p{{forloop.counter}}: Any
+    {% else %}
+    _ p{{forloop.counter}}: {{type}}
+    {% endif %}
+    {{ ", " if not forloop.last }}
+  {% endfor %}
+{% endfilter %}{% endmacro %}
+{% macro argumentsBlock types %}{% filter removeNewlines:"leading" %}
+  {% for type in types %}
+    {% if type == "String" %}
+    String(describing: p{{forloop.counter}})
+    {% elif type == "UnsafeRawPointer" %}
+    Int(bitPattern: p{{forloop.counter}})
+    {% else %}
+    p{{forloop.counter}}
+    {% endif %}
+    {{ ", " if not forloop.last }}
+  {% endfor %}
+{% endfilter %}{% endmacro %}
+{% macro recursiveBlock table item %}
+  {% for string in item.strings %}
+  {% if not param.noComments %}
+  {% for line in string.translation|split:"\n" %}
+  /// {{line}}
+  {% endfor %}
+  {% endif %}
+  {% if string.types %}
+  {{accessModifier}} static func {{string.name|swiftIdentifier:"pretty"|lowerFirstWord|escapeReservedKeywords}}({% call parametersBlock string.types %}) -> String {
+    return {{enumName}}.tr("{{table}}", "{{string.key}}", {% call argumentsBlock string.types %})
+  }
+  {% elif param.lookupFunction %}
+  {# custom localization function is mostly used for in-app lang selection, so we want the loc to be recomputed at each call for those (hence the computed var) #}
+  {{accessModifier}} static var {{string.name|swiftIdentifier:"pretty"|lowerFirstWord|escapeReservedKeywords}}: String { return {{enumName}}.tr("{{table}}", "{{string.key}}") }
+  {% else %}
+  {{accessModifier}} static var {{string.name|swiftIdentifier:"pretty"|lowerFirstWord|escapeReservedKeywords}} = {{enumName}}.tr("{{table}}", "{{string.key}}")
+  {% endif %}
+  {% endfor %}
+  {% for child in item.children %}
+
+  {{accessModifier}} enum {{child.name|swiftIdentifier:"pretty"|escapeReservedKeywords}} {
+    {% filter indent:2 %}{% call recursiveBlock table child %}{% endfilter %}
+  }
+  {% endfor %}
+{% endmacro %}
+// swiftlint:disable explicit_type_interface function_parameter_count identifier_name line_length
+// swiftlint:disable nesting type_body_length type_name vertical_whitespace_opening_braces
+{% set enumName %}{{param.enumName|default:"L10n"}}{% endset %}
+{{accessModifier}} enum {{enumName}} {
+  {% if tables.count > 1 or param.forceFileNameEnum %}
+  {% for table in tables %}
+    {% filter indent:2 %}{% call recursiveBlock table.name table.levels %}{% endfilter %}
+  {% endfor %}
+  {% else %}
+  {% call recursiveBlock tables.first.name tables.first.levels %}
+  {% endif %}
+}
+// swiftlint:enable explicit_type_interface function_parameter_count identifier_name line_length
+// swiftlint:enable nesting type_body_length type_name vertical_whitespace_opening_braces
+
+// MARK: - Implementation Details
+
+extension {{enumName}} {
+  static func tr(_ table: String, _ key: String, _ args: CVarArg...) -> String {
+    // No need to check languages, we always default to en for untranslated strings
+    guard let bundle = Bundle(for: BundleToken.self).lprojBundle(for: "en") else {
+      // no translations for the desired language
+      return key
+    }
+    let format = NSLocalizedString(key, tableName: table, bundle: bundle, comment: "")
+    return String(format: format, locale: Locale(identifier: "en"), arguments: args)
+  }
+}
+
+private final class BundleToken {}
+
+{% else %}
+// No string found
+{% endif %}

Tools/SwiftGen/Templates/Strings/structured-swift5-element.stencil

@@ -78,18 +78,22 @@ extension {{enumName}} {
     let languages = Bundle.preferredLanguages
 
     for language in languages {
-      let translation = trIn(language, table, key, args)
-      if translation != key {
+      if let translation = trIn(language, table, key, args) {
         return translation
+        // If we can't find a translation for this language
+        // we check if we can find one by stripping the region
+      } else if let langCode = Locale(identifier: language).language.languageCode?.identifier,
+        let translation = trIn(langCode, table, key, args) {
+          return translation
+        }
       }
-    }
     return key
-  }
+    }
 
-  private static func trIn(_ language: String, _ table: String, _ key: String, _ args: CVarArg...) -> String {
+  private static func trIn(_ language: String, _ table: String, _ key: String, _ args: CVarArg...) -> String? {
     guard let bundle = Bundle(for: BundleToken.self).lprojBundle(for: language) else {
       // no translations for the desired language
-      return key
+      return nil
     }
     let format = NSLocalizedString(key, tableName: table, bundle: bundle, comment: "")
     return String(format: format, locale: Locale(identifier: language), arguments: args)

Tools/SwiftGen/swiftgen-config.yml

@@ -19,7 +19,7 @@ strings:
   - inputs: Resources/Localizations/en.lproj
     filter: Untranslated*
     outputs:
-      templatePath: Templates/Strings/structured-swift5-element.stencil
+      templatePath: Templates/Strings/structured-swift5-element-untranslated.stencil
       output: Strings+Untranslated.swift
       params:
         enumName: UntranslatedL10n