Add a8c-src-lib attribute to the <string> XML nodes when merging strings from libs

To help identify them more easily in the merged file

and make it clear for developers where they come from (and thus where the source of truth for each string is)

Author: AliSoftware

lib/fastlane/plugin/wpmreleasetoolkit/actions/android/an_localize_libs_action.rb

@@ -32,6 +32,13 @@ def self.details
       end
 
       def self.available_options
+        libs_hash_description = <<~KEYS
+          - `:library`: The library display name
+          - `:strings_path`: The path to the `strings.xml` file of the library
+          - `:exclusions`: An optional `Array` of string keys to exclude from merging
+          - `:source_id`: An optional `String` which will be added as the `a8c-src-lib` XML attribute
+            to strings coming from this library, to help identify their source in the merged file.
+        KEYS
         [
           FastlaneCore::ConfigItem.new(key: :app_strings_path,
                                        description: 'The path of the main strings file',
@@ -41,10 +48,7 @@ def self.available_options
           # See `Fastlane::Helper::Android::LocalizeHelper.merge_lib`'s YARD doc for more details on the keys expected for each Hash.
           FastlaneCore::ConfigItem.new(key: :libs_strings_path,
                                        env_name: 'LOCALIZE_LIBS_STRINGS_PATH',
-                                       description: 'The list of libs to merge. ' \
-                                         + 'Each item in the provided array must be a Hash with the keys `:library` (The library display name),' \
-                                         + '`:strings_path` (The path to the `strings.xml` file of the library) and ' \
-                                         + '`:exclusions` (Array of string keys to exclude from merging)',
+                                       description: "The list of libs to merge. Each item in the provided array must be a Hash with the following keys:\n#{libs_hash_description}",
                                        optional: false,
                                        type: Array),
         ]

lib/fastlane/plugin/wpmreleasetoolkit/helper/android/android_localize_helper.rb

@@ -9,6 +9,8 @@ module Fastlane
   module Helper
     module Android
       module LocalizeHelper
+        LIB_SOURCE_XML_ATTR = 'a8c-src-lib'.freeze
+
         # Checks if string_line has the content_override flag set
         def self.skip_string_by_tag(string_line)
           skip = string_line.attr('content_override') == 'true' unless string_line.attr('content_override').nil?
@@ -35,6 +37,7 @@ def self.skip_string_by_exclusion_list(library, string_name)
         def self.merge_string(main_strings, library, string_line)
           string_name = string_line.attr('name')
           string_content = string_line.content
+          lib_src_id = library[:source_id]
 
           # Skip strings in the exclusions list
           return :skipped if skip_string_by_exclusion_list(library, string_name)
@@ -58,12 +61,14 @@ def self.merge_string(main_strings, library, string_line)
               else
                 # It has the tools:ignore flag, so update the content without touching the other attributes
                 this_string.content = string_content
+                this_string[LIB_SOURCE_XML_ATTR] = lib_src_id unless lib_src_id.nil?
                 return result
               end
             end
           end
 
           # String not found, or removed because needing update and not in the exclusion list: add to the main file
+          string_line[LIB_SOURCE_XML_ATTR] = lib_src_id unless lib_src_id.nil?
           main_strings.xpath('//string').last().add_next_sibling("\n#{' ' * 4}#{string_line.to_xml().strip}")
           return result
         end