Add a ReleaseNotesReader service class

src/lib/y2packager/product_reader.rb

@@ -22,7 +22,6 @@ class ProductReader
     include Yast::Logger
 
     class << self
-
       # Installation packages map
       #
       # This map contains the correspondence between products and the

src/lib/y2packager/release_notes_reader.rb

@@ -0,0 +1,133 @@
+require "yast"
+require "fileutils"
+require "y2packager/package"
+require "pathname"
+
+Yast.import "Directory"
+Yast.import "Pkg"
+
+module Y2Packager
+  # This class is able to read release notes for a given product
+  #
+  # Release notes for a product are available in a specific package which provides
+  # "release-notes()" for the given product. For instance, a package which provides
+  # "release-notes() = SLES" will provide release notes for the SLES product.
+  #
+  # This reader takes care of downloading the release notes package (if any),
+  # extracting its content and returning release notes for a given language/format.
+  class ReleaseNotesReader
+    include Yast::Logger
+
+    # @return [Pathname] Place to store all release notes
+    attr_reader :work_dir
+
+    # Constructor
+    #
+    # @param work_dir [Pathname] Temporal directory to work
+    def initialize(work_dir = nil)
+      @work_dir = work_dir || Pathname(Yast::Directory.tmpdir).join("release-notes")
+    end
+
+    # Get release notes for a given product
+    #
+    # Release notes are downloaded and extracted to work directory.  When
+    # release notes for a language "xx_XX" are not found, it will fallback to
+    # "xx".
+    #
+    # @param product [Y2Packager::Product] Product
+    # @param lang    [String]              Release notes language (falling back to "en")
+    # @param format  [Symbol]              Release notes format (:txt or :rtf)
+    # @return [String,nil] Release notes or nil if a release notes were not found
+    #   (no package providing release notes or notes not found in the package)
+    def for(product, lang: "en_US", format: :txt)
+      package = release_notes_package_for(product)
+      return nil if package.nil?
+      download_and_extract(package)
+      content = release_notes_content(package, lang, format)
+      cleanup
+      content
+    end
+
+  private
+
+    def cleanup
+      ::FileUtils.rm_r(work_dir) if work_dir.directory?
+    end
+
+    # Return the release notes package for a given product
+    #
+    # This method queries libzypp asking for the package which contains release
+    # notes for the given product. It relies on the `release-notes()` tag.
+    #
+    # @param product [Product] Product
+    # @return [Package,nil] Package containing the release notes; nil if not found
+    def release_notes_package_for(product)
+      provides = Yast::Pkg.PkgQueryProvides("release-notes()")
+      release_notes_packages = provides.map(&:first).uniq
+      package_name = release_notes_packages.find do |name|
+        dependencies = Yast::Pkg.ResolvableDependencies(name, :package, "").first["deps"]
+        dependencies.any? do |dep|
+          dep["provides"].to_s.match(/release-notes\(\)\s*=\s*#{product.name}\s*/)
+        end
+      end
+      return nil if package_name.nil?
+      # FIXME: make sure we get the latest version
+      Y2Packager::Package.find(package_name).find { |s| s.status == :available }
+    end
+
+    # Return release notes content for a package, language and format
+    #
+    # Release notes are downloaded and extracted to work directory.  When
+    # release notes for a language "xx_XX" are not found, it will fallback to
+    # "xx".
+    #
+    # @param package [String] Release notes package name
+    # @param lang    [String] Language code ("en_US", "en", etc.)
+    # @param format  [Symbol] Content format (:txt, :rtf, etc.).
+    # @see release_notes_file
+    def release_notes_content(package, lang, format)
+      file = release_notes_file(package, lang, format)
+      file ? File.read(file) : nil
+    end
+
+    FALLBACK_LANGS = ["en_US", "en"].freeze
+    # Return release notes file path for a given package, language and format
+    #
+    # Release notes are downloaded and extracted to work directory.  When
+    # release notes for a language "xx_XX" are not found, it will fallback to
+    # "xx".
+    #
+    # @param package [String] Release notes package name
+    # @param lang    [String] Language code ("en_US", "en", etc.)
+    # @param format  [Symbol] Content format (:txt, :rtf, etc.).
+    def release_notes_file(package, lang, format)
+      langs = [lang]
+      langs << lang[0..1] if lang.size > 2
+      langs.concat(FALLBACK_LANGS)
+
+      Dir.glob(
+        File.join(
+          release_notes_path(package), "**", "RELEASE-NOTES.{#{langs.join(",")}}.#{format}"
+        )
+      ).first
+    end
+
+    # Download and extract package
+    #
+    # @return [Boolean]
+    def download_and_extract(package)
+      target = release_notes_path(package)
+      return true if ::File.directory?(target)
+      ::FileUtils.mkdir_p(target)
+      package.extract_to(target)
+    end
+
+    # Return the location of the extracted release notes package
+    #
+    # @param [Package] Release notes package
+    # @return [String] Path to extracted release notes
+    def release_notes_path(package)
+      work_dir.join(package.name)
+    end
+  end
+end

test/lib/release_notes_reader_test.rb

@@ -0,0 +1,109 @@
+#!/usr/bin/env rspec
+
+require_relative "../test_helper"
+require "y2packager/release_notes_reader"
+require "y2packager/product"
+
+describe Y2Packager::ReleaseNotesReader do
+  subject(:reader) { described_class.new(work_dir) }
+
+  let(:work_dir) { FIXTURES_PATH.join("release-notes") }
+
+  let(:product) do
+    instance_double(Y2Packager::Product, name: "dummy")
+  end
+
+  let(:package) do
+    Y2Packager::Package.new("release-notes-dummy", 2, :available)
+  end
+
+  let(:dependencies) do
+    [
+      { "deps" => [{ "provides" => "release-notes() = dummy" }] }
+    ]
+  end
+
+  let(:provides) do
+    [["release-notes-dummy", :CAND, :NONE]]
+  end
+
+  before do
+    allow(Yast::Pkg).to receive(:PkgQueryProvides).with("release-notes()")
+      .and_return(provides)
+    allow(Yast::Pkg).to receive(:ResolvableDependencies)
+      .with("release-notes-dummy", :package, "").and_return(dependencies)
+    allow(Y2Packager::Package).to receive(:find).with(package.name).and_return([package])
+    allow(package).to receive(:download_to) do |path|
+      ::FileUtils.mkdir_p(path) unless work_dir.directory?
+      ::FileUtils.cp(FIXTURES_PATH.join("release-notes-dummy.rpm"), path)
+      true
+    end
+  end
+
+  describe "#for" do
+    let(:download) { true }
+
+    it "returns product release notes in english" do
+      expect(reader.for(product)).to eq("Release Notes\n")
+    end
+
+    it "cleans up temporary files" do
+      reader.for(product)
+      expect(File).to_not be_directory(work_dir)
+    end
+
+    context "when a full language code is given (xx_XX)" do
+      it "returns product release notes for the given language" do
+        expect(reader.for(product, lang: "en_US")).to eq("Release Notes\n")
+      end
+
+      context "and release notes are not available" do
+        it "returns product release notes for the short language code (xx)" do
+          expect(reader.for(product, lang: "de_DE")).to eq("Versionshinweise\n")
+        end
+      end
+    end
+
+    context "when a format is given" do
+      it "returns product release notes in the given format" do
+        expect(reader.for(product, format: :html))
+          .to eq("<h1>Release Notes</h1>\n")
+      end
+
+      context "and release notes are not available in the given format" do
+        it "returns the english version" do
+          expect(reader.for(product, lang: "de_DE", format: :html))
+            .to eq("<h1>Release Notes</h1>\n")
+        end
+      end
+    end
+
+    context "when release notes are not available" do
+      it "returns the english version" do
+        expect(reader.for(product, lang: "es")).to eq("Release Notes\n")
+      end
+    end
+
+    context "when package could not be retrieved" do
+      before do
+        allow(package).to receive(:extract_to).and_return(false)
+      end
+
+      it "returns nil" do
+        expect(reader.for(product)).to be_nil
+      end
+    end
+
+    context "when no package containing release notes was found" do
+      let(:provides) { [] }
+
+      it "returns nil" do
+        expect(reader.for(product)).to be_nil
+      end
+    end
+  end
+
+  after do
+    ::FileUtils.rm_rf(work_dir) if work_dir.exist?
+  end
+end