Add Product#release_notes

* Get product release notes.
* It relies on Y2Packager::ReleaseNotesReader.

src/lib/y2packager/product.rb

@@ -13,6 +13,7 @@
 Yast.import "Pkg"
 Yast.import "Language"
 require "y2packager/product_reader"
+require "y2packager/release_notes_reader"
 
 module Y2Packager
   # Represent a product which is present in a repository. At this
@@ -185,5 +186,16 @@ def license_confirmation=(confirmed)
     def license_confirmed?
       Yast::Pkg.PrdHasLicenseConfirmed(name)
     end
+
+    # Return product's release notes
+    #
+    # @param format     [Symbol] Release notes format (:txt, :rtf, etc.)
+    # @return pref_lang [String] Preferred language (fallback to english)
+    # @return [String] Release notes
+    # @see ReleaseNotesReader
+    def release_notes(format = :txt, lang = nil)
+      release_notes_lang = lang || Yast::Language.language
+      ReleaseNotesReader.new.for(self, lang: release_notes_lang, format: format)
+    end
   end
 end

test/product_test.rb

@@ -266,4 +266,30 @@
       end
     end
   end
+
+  describe "#release_notes" do
+    let(:reader) { Y2Packager::ReleaseNotesReader.new }
+    let(:lang) { "en_US" }
+    let(:relnotes_content) { "Release Notes" }
+
+    before do
+      allow(Y2Packager::ReleaseNotesReader).to receive(:new)
+        .and_return(reader)
+      allow(Yast::Language).to receive(:language).and_return(lang)
+    end
+
+    it "returns release notes in the current language" do
+      expect(reader).to receive(:for).with(product, lang: lang, format: :txt)
+        .and_return(relnotes_content)
+      expect(product.release_notes).to eq(relnotes_content)
+    end
+
+    context "when language/format are given" do
+      it "returns release notes in the given language/format" do
+        expect(reader).to receive(:for).with(product, lang: "de_DE", format: :rtf)
+          .and_return(relnotes_content)
+        expect(product.release_notes(:rtf, "de_DE")).to eq(relnotes_content)
+      end
+    end
+  end
 end