changelog endpoint ecosyste-ms/roadmap#14

app/controllers/api/v1/archives_controller.rb

@@ -26,4 +26,15 @@ def readme
       render json: readme
     end
   end
+
+  def changelog
+    expires_in(60.days, public: true, "s-maxage" => 60.days) # TODO this needs to be more dynamic to take into account headers from where the file was loaded
+    @archive = Archive.new(params[:url])
+    changelog = @archive.changelog
+    if changelog.nil?
+      render json: {:error => "path not found"}, :status => 404
+    else
+      render json: changelog
+    end
+  end
 end

app/models/archive.rb

@@ -159,4 +159,33 @@ def readme
       }
     end
   end
+
+  def changelog
+    Dir.mktmpdir do |dir|
+      download_file(dir)
+      base_path = extract(dir)
+
+      return nil if base_path.nil?
+      all_files = Dir.glob("**/*", File::FNM_DOTMATCH, base: base_path).tap{|a| a.delete(".")}
+
+      changelog_files = all_files.select{|path| path.match(/^changelog/i) }
+
+      return nil if changelog_files.empty?
+
+      changelog_file = changelog_files.first
+
+      raw = File.read(File.join(base_path, changelog_file))
+      html = GitHub::Markup.render(changelog_file, raw.force_encoding("UTF-8"))
+      language = GitHub::Markup.language(changelog_file, raw.force_encoding("UTF-8")).try(:name)
+
+      return {
+        name: changelog_file,
+        raw: raw,
+        html: html,
+        plain: Nokogiri::HTML(html).try(:text),
+        extension: File.extname(changelog_file),
+        language: language
+      }
+    end
+  end
 end

config/routes.rb

@@ -9,6 +9,7 @@
           get :list
           get :contents
           get :readme
+          get :changelog
         end
       end
     end

openapi/api/v1/openapi.yaml

@@ -78,6 +78,24 @@ paths:
             application/json:
               schema:
                 $ref: '#/components/schemas/Readme'
+  /archives/changelog:
+    get:
+      summary: get changelog from a package archive
+      operationId: changelog
+      parameters:
+        - name: url
+          in: query
+          description: url to package archive
+          required: true
+          schema:
+            type: string
+      responses:
+        200:
+          description: OK
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Changelog'
 components:
   schemas:
     Content:
@@ -107,4 +125,19 @@ components:
         other_readme_files:
           type: array
           items:
-            type: string
+            type: string
+    Changelog:
+      type: object
+      properties:
+        name:
+          type: string
+        raw:
+          type: string
+        html:
+          type: string
+        plain:
+          type: string
+        extension:
+          type: string
+        language:
+          type: string

test/controllers/api/v1/archives_controller_test.rb

@@ -164,4 +164,21 @@ class ApiV1ArchivesControllerTest < ActionDispatch::IntegrationTest
     assert_equal actual_response['language'], "Markdown"
     assert_equal actual_response['other_readme_files'], []
   end
+
+  test 'changelog' do
+    stub_request(:get, "https://github.com/splitrb/split/archive/refs/heads/main.zip")
+      .to_return({ status: 200, body: File.open(File.join(Rails.root, 'test', 'fixtures', 'files','main.zip')).read })
+
+    get changelog_api_v1_archives_path(url: 'https://github.com/splitrb/split/archive/refs/heads/main.zip')
+    assert_response :success
+    actual_response = JSON.parse(@response.body)
+
+    assert_equal actual_response['name'], 'CHANGELOG.md'
+    assert_equal actual_response['raw'][0..20], "# 4.0.2 (December 2nd"
+    assert_equal actual_response['html'][0..30], "<h1>4.0.2 (December 2nd, 2022)<"
+    assert_equal actual_response['plain'][0..8], "4.0.2 (De"
+
+    assert_equal actual_response['extension'], '.md'
+    assert_equal actual_response['language'], "Markdown"
+  end
 end