gettext_scanner.rb

#lib/gettext_scanner.rb
require 'i18n/tasks/scanners/pattern_scanner'

class GettextScanner < I18n::Tasks::Scanners::PatternScanner

  QUOTES              = ["'".freeze, '"'.freeze].freeze
  VALID_KEY_CHARS     = /(?:[[:word:]]|[-\s.?'!,\(\)\)\/“”–;<>À-ž])/
  VALID_KEY_RE = /^(#{VALID_KEY_CHARS}|[%:\#{@}\[\]])+$/

  def translate_call_re
    /(?<=^|[^\w'\-])t|_(?:ranslate)?/
  end

  def valid_key?(key)
    key =~ VALID_KEY_RE
  end

  def scan_file(path)
    keys = []
    text = read_file(path)
    text.scan(@pattern) do |match|
      src_pos  = Regexp.last_match.offset(0).first
      location = occurrence_from_position(path, text, src_pos)
      next if exclude_line?(location.line, path)
      key = match_to_key(match, path, location)
      next unless key
      next unless valid_key?(key)
      keys << [key, location]
    end
    keys
  rescue Exception => e
    raise ::I18n::Tasks::CommandError.new(e, "Error scanning #{path}: #{e.message}")
  end
end

I18n::Tasks.add_scanner "GettextScanner", only: %w(*.haml *.erb)

i18n-tasks.yml.erb

#config/i18n-tasks.yml.erb

<% require './lib/gettext_scanner.rb' %>
# i18n-tasks finds and manages missing and unused translations: https://github.com/glebm/i18n-tasks

# The "main" locale.
base_locale: en
## All available locales are inferred from the data by default. Alternatively, specify them explicitly:
# locales: [es, fr]
## Reporting locale, default: en. Available: en, ru.
# internal_locale: en

# Read and write translations.
data:
  yaml:
    write:
      # do not wrap lines at 80 characters
      line_width: -1

# Find translate calls
search:
  scanner: GettextScanner