```ruby
# frozen_string_literal: true

require File.expand_path('../test_helper.rb', File.dirname(__FILE__))

describe Pango::Font do
  before do
    ctx = Gdk.pango_context_get
    fontmap = ctx.get_font_map
    fd = Pango::FontDescription.new
    @fnt = fontmap.load_font ctx, fd
  end

  describe '#get_coverage' do
    before do
      lang = Pango::Language.from_string 'en'
      @cov = @fnt.get_coverage lang
    end

    it 'returns an instance of Pango::Coverage' do
      _(@cov).must_be_instance_of Pango::Coverage
    end

    it 'returns valid coverage info' do
      _(@cov.get(' '[0].ord)).must_equal :exact
    end
  end

  describe '#coverage' do
    let(:lang) { Pango::Language.from_string 'en' }
    let(:cov) { @fnt.coverage lang }

    it 'returns an instance of Pango::Coverage' do
      _(cov).must_be_instance_of Pango::Coverage
    end

    it 'returns valid coverage info' do
      _(cov.get(' '[0].ord)).must_equal :exact
    end
  end
end
```

Use nice alias to fetch font map
user
```ruby
# frozen_string_literal: true

require File.expand_path('../test_helper.rb', File.dirname(__FILE__))

describe Pango::Font do
  before do
    ctx = Gdk.pango_context_get
    fontmap = ctx.font_map
    fd = Pango::FontDescription.new
    @fnt = fontmap.load_font ctx, fd
  end

  describe '#get_coverage' do
    before do
      lang = Pango::Language.from_string 'en'
      @cov = @fnt.get_coverage lang
    end

    it 'returns an instance of Pango::Coverage' do
      _(@cov).must_be_instance_of Pango::Coverage
    end

    it 'returns valid coverage info' do
      _(@cov.get(' '[0].ord)).must_equal :exact
    end
  end

  describe '#coverage' do
    let(:lang) { Pango::Language.from_string 'en' }
    let(:cov) { @fnt.coverage lang }

    it 'returns an instance of Pango::Coverage' do
      _(cov).must_be_instance_of Pango::Coverage
    end

    it 'returns valid coverage info' do
      _(cov.get(' '[0].ord)).must_equal :exact
    end
  end
end
```
assistant