GitService: Move factory part into dedicated module

lib/modulesync/git_service.rb

@@ -5,24 +5,6 @@ class Error < StandardError; end
   module GitService
     class MissingCredentialsError < Error; end
 
-    def self.instantiate(type:, endpoint:, token:)
-      raise MissingCredentialsError, <<~MESSAGE if token.nil?
-        A token is required to use services from #{type}:
-          Please set environment variable: "#{type.upcase}_TOKEN" or set the token entry in module options.
-      MESSAGE
-
-      case type
-      when :github
-        require 'modulesync/git_service/github'
-        ModuleSync::GitService::GitHub.new(token, endpoint)
-      when :gitlab
-        require 'modulesync/git_service/gitlab'
-        ModuleSync::GitService::GitLab.new(token, endpoint)
-      else
-        raise NotImplementedError, "Unable to manage a PR/MR for Git service: '#{type}'"
-      end
-    end
-
     def self.configuration_for(sourcecode:)
       type = type_for(sourcecode: sourcecode)
 

lib/modulesync/git_service/factory.rb

@@ -0,0 +1,23 @@
+module ModuleSync
+  module GitService
+    module Factory
+      def self.instantiate(type:, endpoint:, token:)
+        raise MissingCredentialsError, <<~MESSAGE if token.nil?
+        A token is required to use services from #{type}:
+          Please set environment variable: "#{type.upcase}_TOKEN" or set the token entry in module options.
+        MESSAGE
+
+        case type
+        when :github
+          require 'modulesync/git_service/github'
+          ModuleSync::GitService::GitHub.new(token, endpoint)
+        when :gitlab
+          require 'modulesync/git_service/gitlab'
+          ModuleSync::GitService::GitLab.new(token, endpoint)
+        else
+          raise NotImplementedError, "Unable to manage a PR/MR for Git service: '#{type}'"
+        end
+      end
+    end
+  end
+end

lib/modulesync/source_code.rb

@@ -1,5 +1,6 @@
 require 'modulesync'
 require 'modulesync/git_service'
+require 'modulesync/git_service/factory'
 require 'modulesync/repository'
 require 'modulesync/util'
 
@@ -49,7 +50,7 @@ def path(*parts)
     end
 
     def git_service
-      @git_service ||= GitService.instantiate(**git_service_configuration)
+      @git_service ||= GitService::Factory.instantiate(**git_service_configuration)
     end
 
     def git_service_configuration

spec/unit/modulesync/git_service/factory_spec.rb

@@ -0,0 +1,16 @@
+require 'modulesync'
+require 'modulesync/git_service/factory'
+
+describe ModuleSync::GitService::Factory do
+  context 'when instantiate a GitHub service without credentials' do
+    it 'raises an error' do
+      expect { ModuleSync::GitService::Factory.instantiate(type: :github, endpoint: nil, token: nil) }.to raise_error(ModuleSync::GitService::MissingCredentialsError)
+    end
+  end
+
+  context 'when instantiate a GitLab service without credentials' do
+    it 'raises an error' do
+      expect { ModuleSync::GitService::Factory.instantiate(type: :gitlab, endpoint: nil, token: nil) }.to raise_error(ModuleSync::GitService::MissingCredentialsError)
+    end
+  end
+end

spec/unit/modulesync/git_service_spec.rb

@@ -9,18 +9,6 @@
     ModuleSync.instance_variable_set '@options', options
   end
 
-  context 'when instantiate a GitHub service without credentials' do
-    it 'raises an error' do
-      expect { ModuleSync::GitService.instantiate(type: :github, endpoint: nil, token: nil) }.to raise_error(ModuleSync::GitService::MissingCredentialsError)
-    end
-  end
-
-  context 'when instantiate a GitLab service without credentials' do
-    it 'raises an error' do
-      expect { ModuleSync::GitService.instantiate(type: :gitlab, endpoint: nil, token: nil) }.to raise_error(ModuleSync::GitService::MissingCredentialsError)
-    end
-  end
-
   context 'when guessing the git service configuration' do
     before do
       allow(ENV).to receive(:[])