Rails i18n create missing translations using page HTML span hints in pair with rspec to automate the process fully

create_missing_translations.rb

findings = [["translation missing: en.admin_dashboard.sprint_widget.sprint", "Sprint"]]
create_translations(findings, locales = ["en", "fi"], dry_run: false)

# rspec usage: I18N_CREATE_MISSING=1 bundle exec rspec

html_page.rb

require "nokogiri"

RSpec.shared_examples_for "html page" do |path: nil, text: nil|
  let(:parsed_body) { Nokogiri.HTML5(page.body) }

  if path.present?
    it "has correct path" do
      expect(page).to have_current_path(path, ignore_query: true)
    end
  end

  if text.present?
    it "has correct text" do
      expect(page).to have_text(text)
    end
  end

  it "has valid html" do
    expect(parsed_body).to be_a(Nokogiri::HTML::Document)
    expect(parsed_body.errors).to be_empty
  end

  it "has no missing translations" do
    missing_translations = parsed_body.css("span.translation_missing").map do |span|
      [span["title"], span.text]
    end
    if ENV["I18N_CREATE_MISSING"].present?
      I18nTools.create_translations(missing_translations, dry_run: false)
    end
    expect(missing_translations).to be_empty
  end
end

i18n_tools.rb

module I18nTools
  def self.create_translations(findings, locales = I18n.available_locales, dry_run: true, override: false)
    locales.each do |locale|
      file_path = "config/locales/#{locale}.yml"
      next unless File.exist?(file_path)

      file = YAML.load_file(file_path)
      findings.each do |finding|
        cursor = file
        path = finding[0].gsub("translation missing: ", "").split(".")
        path[0] = locale
        path[0..-2].each do |path|
          cursor = cursor[path] || (cursor[path] = {})
        end
        translation = finding[1]
        translation_key = path.last
        cursor[translation_key] = translation if cursor[translation_key].blank? || override
        puts "#{path.join(".")} => #{translation}"
      end
      File.write(file_path, file.to_yaml) unless dry_run
    end
  end
end