Fix error when git upstream branch is deleted

features/step_definitions/git_steps.rb

@@ -83,3 +83,8 @@
   pmrr = ModuleSync::Faker::PuppetModuleRemoteRepo.new(name, namespace)
   expect(pmrr.tags).not_to include(tag)
 end
+
+Given 'the branch {string} of the puppet module {string} from {string} is deleted' do |branch, name, namespace|
+  pmrr = ModuleSync::Faker::PuppetModuleRemoteRepo.new(name, namespace)
+  pmrr.delete_branch(branch)
+end

features/update.feature

@@ -755,3 +755,25 @@ Feature: update
       workdir: modules/fakenamespace/puppet-test
       """
     And the puppet module "puppet-test" from "fakenamespace" should have no commits made by "Aruba"
+
+  # This reproduces the issue: https://github.com/voxpupuli/modulesync/issues/81
+  Scenario: Resync repositories after upstream branch deletion
+    Given a basic setup with a puppet module "puppet-test" from "fakenamespace"
+    And a file named "config_defaults.yml" with:
+      """
+      ---
+      test:
+        name: aruba
+      """
+    And a directory named "moduleroot"
+    And a file named "moduleroot/test.erb" with:
+      """
+      <%= @configs['name'] %>
+      """
+    When I run `msync update -m "No changes!" --branch delete-me`
+    Then the exit status should be 0
+    And the puppet module "puppet-test" from "fakenamespace" should have 1 commit made by "Aruba" in branch "delete-me"
+    When the branch "delete-me" of the puppet module "puppet-test" from "fakenamespace" is deleted
+    And I run `msync update -m "No changes!" --branch delete-me`
+    Then the exit status should be 0
+    And the puppet module "puppet-test" from "fakenamespace" should have no commits made by "Aruba"

lib/modulesync/repository.rb

@@ -74,7 +74,7 @@ def prepare_workspace(branch)
         Dir.chdir(@directory) do
           puts "Overriding any local changes to repository in '#{@directory}'"
           @git = Git.open('.')
-          repo.fetch
+          repo.fetch 'origin', prune: true
           repo.reset_hard
           switch_branch(branch)
           git.pull('origin', branch) if remote_branch_exists?(branch)

spec/helpers/faker/puppet_module_remote_repo.rb

@@ -105,6 +105,12 @@ def tags
         end
       end
 
+      def delete_branch(branch)
+        FileUtils.chdir(bare_repo_dir) do
+          run %W{git branch -D #{branch}}
+        end
+      end
+
       def remote_url
         "file://#{bare_repo_dir}"
       end