Fix metadata length computation logic (#383)

Author: mokagio

CHANGELOG.md

@@ -14,7 +14,7 @@ _None_
 
 ### Bug Fixes
 
-_None_
+- Fix metadata length computation logic [[#383](https://github.com/wordpress-mobile/release-toolkit/pull/383)]
 
 ### Internal Changes
 
@@ -55,7 +55,7 @@ _None_
 
 ### New Features
 
-* Add the option for `an_localize_libs` to provide a `source_id` for each library being merged.  
+* Add the option for `an_localize_libs` to provide a `source_id` for each library being merged.
   If provided, that identifier will be added as an `a8c-src-lib` XML attribute to the `<string>` nodes being updated with strings from said library.
   This can be useful to help identify where each string come from in the resulting, merged `strings.xml`. [#351]
 * Add the option for `an_localize_libs` to set the `tools:ignore="UnusedResources"` XML attribute for each string being merged from a library. [#354]

lib/fastlane/plugin/wpmreleasetoolkit/helper/metadata_download_helper.rb

@@ -40,7 +40,7 @@ def parse_data(target_locale, loc_data, is_source)
           target_files.each do |file|
             if file[0].to_s == key
               data = file[1]
-              msg = is_source ? source : d[1]
+              msg = is_source ? source : d[1].first || '' # In the JSON, each Hash value is an array, with zero or one entry
               update_key(target_locale, key, file, data, msg)
             end
           end
@@ -58,15 +58,15 @@ def reparse_alternates(target_locale, loc_data, is_source)
             if file[0].to_s == key
               puts "Alternate: #{key}"
               data = file[1]
-              msg = is_source ? source : d[1]
+              msg = is_source ? source : d[1].first || '' # In the JSON, each Hash value is an array, with zero or one entry
               update_key(target_locale, key, file, data, msg)
             end
           end
         end
       end
 
       def update_key(target_locale, key, file, data, msg)
-        message_len = msg.to_s.length - 4 # Don't count JSON delimiters.
+        message_len = msg.length
         if (data.key?(:max_size)) && (data[:max_size] != 0) && ((message_len) > data[:max_size])
           if data.key?(:alternate_key)
             UI.message("#{target_locale} translation for #{key} exceeds maximum length (#{message_len}). Switching to the alternate translation.")