[Linter] Cleanup the github sources checks

lib/cocoapods-core/specification/linter.rb

@@ -335,23 +335,26 @@ def perform_github_source_checks(s)
         if git = s[:git]
           return unless git =~ /^#{URI.regexp}$/
           git_uri = URI.parse(git)
-          if git_uri.host == 'www.github.com'
-            results.add_warning('github_sources', 'Github repositories should ' \
-             'not use `www` in their URL.')
-          end
-          if git_uri.host == 'github.com' || git_uri.host == 'gist.github.com'
-            unless git.end_with?('.git')
-              results.add_warning('github_sources', 'Github repositories ' \
-              'should end in `.git`.')
-            end
-            unless git_uri.scheme == 'https'
-              results.add_warning('github_sources', 'Github repositories ' \
-                'should use an `https` link.')
-            end
+          return unless git_uri.host.end_with?('github.com')
+          perform_github_uri_checks(git_uri)
+          unless git.end_with?('.git')
+            results.add_warning('github_sources', 'Github repositories ' \
+            'should end in `.git`.')
           end
         end
       end
 
+      def perform_github_uri_checks(git_uri)
+        if git_uri.host.start_with?('www.')
+          results.add_warning('github_sources', 'Github repositories should ' \
+           'not use `www` in their URL.')
+        end
+        unless git_uri.scheme == 'https'
+          results.add_warning('github_sources', 'Github repositories ' \
+            'should use an `https` link.')
+        end
+      end
+
       # Performs validations related to SSH sources
       #
       def check_git_ssh_source(s)
@@ -377,8 +380,6 @@ def _validate_social_media_url(s)
 
       # @!group All specs validation helpers
 
-      private
-
       # Performs validations related to the `compiler_flags` attribute.
       #
       def _validate_compiler_flags(flags)

spec/specification/linter_spec.rb

@@ -271,6 +271,11 @@ def result_should_include(*values)
         result_should_include('Github', 'www')
       end
 
+      it 'checks that Gist Github repositories do not use `www`' do
+        @spec.stubs(:source).returns(:git => 'https://www.gist.github.com/2823399.git', :tag => '1.0')
+        result_should_include('Github', 'www')
+      end
+
       it 'checks that Github repositories end in .git (for compatibility)' do
         @spec.stubs(:source).returns(:git => 'https://github.com/repo', :tag => '1.0')
         result_should_include('Github', '.git')