Refactor Wiki formats handling

In this commit we're introducing a new way of registering markups
to the Wiki. This way, introducing new ones or handling the
existing ones is easier.

app/helpers/wiki_helper.rb

@@ -139,6 +139,10 @@ module WikiHelper
     api_v4_projects_wikis_path(wiki_page_render_api_endpoint_params(page))
   end
 
+  def wiki_markup_hash_by_name_id
+    Wiki::VALID_USER_MARKUPS.map { |key, value| { value[:name] => key } }.reduce({}, :merge)
+  end
+
   private
 
   def wiki_page_render_api_endpoint_params(page)

app/models/wiki.rb

@@ -10,18 +10,45 @@ class Wiki
   extend ActiveModel::Naming
 
   MARKUPS = { # rubocop:disable Style/MultilineIfModifier
-    'Markdown' => :markdown,
-    'RDoc'     => :rdoc,
-    'AsciiDoc' => :asciidoc,
-    'Org'      => :org
+    markdown: {
+      name: 'Markdown',
+      default_extension: :md,
+      created_by_user: true
+    },
+    rdoc: {
+      name: 'RDoc',
+      default_extension: :rdoc,
+      created_by_user: true
+    },
+    asciidoc: {
+      name: 'AsciiDoc',
+      default_extension: :asciidoc,
+      created_by_user: true
+    },
+    org: {
+      name: 'Org',
+      default_extension: :org,
+      created_by_user: true
+    },
+    textile: {
+      name: 'Textile',
+      default_extension: :textile
+    },
+    creole: {
+      name: 'Creole',
+      default_extension: :creole
+    },
+    rest: {
+      name: 'reStructuredText',
+      default_extension: :rst
+    },
+    mediawiki: {
+      name: 'MediaWiki',
+      default_extension: :mediawiki
+    }
   }.freeze unless defined?(MARKUPS)
 
-  DEFAULT_MARKUP_EXTENSIONS = { # rubocop:disable Style/MultilineIfModifier
-    markdown: 'md',
-    rdoc:     'rdoc',
-    asciidoc: 'asciidoc',
-    org:      'org'
-  }.freeze unless defined?(DEFAULT_MARKUP_EXTENSIONS)
+  VALID_USER_MARKUPS = MARKUPS.select { |_, v| v[:created_by_user] }.freeze unless defined?(VALID_USER_MARKUPS)
 
   CouldNotCreateWikiError = Class.new(StandardError)
 
@@ -355,13 +382,15 @@ class Wiki
   end
 
   def with_valid_format(format, &block)
-    unless Wiki::MARKUPS.value?(format.to_sym)
+    default_extension = Wiki::VALID_USER_MARKUPS.dig(format.to_sym, :default_extension).to_s
+
+    if default_extension.blank?
       @error_message = _('Invalid format selected')
 
       return false
     end
 
-    yield Wiki::DEFAULT_MARKUP_EXTENSIONS[format.to_sym]
+    yield default_extension
   end
 
   def sluggified_full_path(title, extension)

app/models/wiki_page.rb

@@ -185,7 +185,7 @@ class WikiPage
   #       :content - The raw markup content.
   #       :format  - Optional symbol representing the
   #                  content format. Can be any type
-  #                  listed in the Wiki::MARKUPS
+  #                  listed in the Wiki::VALID_USER_MARKUPS
   #                  Hash.
   #       :message - Optional commit message to set on
   #                  the new page.
@@ -205,7 +205,7 @@ class WikiPage
   # attrs - Hash of attributes to be updated on the page.
   #        :content         - The raw markup content to replace the existing.
   #        :format          - Optional symbol representing the content format.
-  #                           See Wiki::MARKUPS Hash for available formats.
+  #                           See Wiki::VALID_USER_MARKUPS Hash for available formats.
   #        :message         - Optional commit message to set on the new version.
   #        :last_commit_sha - Optional last commit sha to validate the page unchanged.
   #        :title           - The Title (optionally including dir) to replace existing title

app/views/shared/wikis/_form.html.haml

@@ -3,4 +3,4 @@
 .gl-mt-3
   = form_errors(@page, truncate: :title)
 
-#js-wiki-form{ data: { page_info: page_info.to_json, format_options: Wiki::MARKUPS.to_json } }
+#js-wiki-form{ data: { page_info: page_info.to_json, format_options: wiki_markup_hash_by_name_id.to_json } }

lib/api/wikis.rb

@@ -12,7 +12,7 @@ module API
       params :common_wiki_page_params do
         optional :format,
           type: String,
-          values: Wiki::MARKUPS.values.map(&:to_s),
+          values: Wiki::VALID_USER_MARKUPS.keys.map(&:to_s),
           default: 'markdown',
           desc: 'Format of a wiki page. Available formats are markdown, rdoc, asciidoc and org'
       end

spec/support/shared_examples/features/wiki/user_creates_wiki_page_shared_examples.rb

@@ -20,6 +20,12 @@ RSpec.shared_examples 'User creates wiki page' do
       click_link "Create your first page"
     end
 
+    it 'shows all available formats in the dropdown' do
+      Wiki::VALID_USER_MARKUPS.each do |key, markup|
+        expect(page).to have_css("#wiki_format option[value=#{key}]", text: markup[:name])
+      end
+    end
+
     it "disables the submit button", :js do
       page.within(".wiki-form") do
         fill_in(:wiki_content, with: "")

spec/support/shared_examples/models/wiki_shared_examples.rb

@@ -11,6 +11,10 @@ RSpec.shared_examples 'wiki model' do
 
   subject { wiki }
 
+  it 'VALID_USER_MARKUPS contains all valid markups' do
+    expect(described_class::VALID_USER_MARKUPS.keys).to match_array(%i(markdown rdoc asciidoc org))
+  end
+
   it 'container class includes HasWiki' do
     # NOTE: This is not enforced at runtime, since we also need to support Geo::DeletedProject
     expect(wiki_container).to be_kind_of(HasWiki)
@@ -520,6 +524,15 @@ RSpec.shared_examples 'wiki model' do
       end
     end
 
+    context 'when format is not allowed' do
+      let!(:page) { create(:wiki_page, wiki: subject, title: 'test page') }
+
+      it 'returns false and sets error message' do
+        expect(subject.update_page(page.page, content: 'new content', format: :creole)).to eq false
+        expect(subject.error_message).to match(/Invalid format selected/)
+      end
+    end
+
     context 'when page path does not have a default extension' do
       let!(:page) { create(:wiki_page, wiki: subject, title: 'test page') }