Allow Specification of Base Branch

CHANGELOG.md

@@ -8,6 +8,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Add
 - Support for Ruby 3. ([#79])
+- Allow specification of base branch, upone which to base the pull-request
+  ([#80])
 
 ### Changed
 - Moved CI to GitHub Actions ([#78])
@@ -17,6 +19,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 [#77]: https://github.com/envato/unwrappr/pull/77
 [#78]: https://github.com/envato/unwrappr/pull/78
 [#79]: https://github.com/envato/unwrappr/pull/79
+[#80]: https://github.com/envato/unwrappr/pull/80
 
 ## [0.4.0] 2020-04-14
 ### Changed

lib/unwrappr/cli.rb

@@ -8,6 +8,15 @@ module Unwrappr
   class CLI < Clamp::Command
     self.default_subcommand = 'all'
 
+    option(['-b', '--base'],
+           'BRANCH',
+           <<~DESCRIPTION,
+             the branch upon which to base the pull-request. Omit this option
+             to use the current branch, or repository's default branch
+             (typically 'origin/main') on clone.
+           DESCRIPTION
+           attribute_name: :base_branch)
+
     option ['-v', '--version'], :flag, 'Show version' do
       puts "unwrappr v#{Unwrappr::VERSION}"
       exit(0)
@@ -16,7 +25,7 @@ class CLI < Clamp::Command
     subcommand 'all', 'run bundle update, push to github, '\
                       'create a pr and annotate changes' do
       def execute
-        Unwrappr.run_unwapper_in_pwd
+        Unwrappr.run_unwapper_in_pwd(base_branch: base_branch)
       end
     end
 
@@ -59,18 +68,18 @@ def execute
             )
           end
 
-          Dir.chdir(repo) { Unwrappr.run_unwapper_in_pwd }
+          Dir.chdir(repo) { Unwrappr.run_unwapper_in_pwd(base_branch: base_branch) }
         end
       end
     end
   end
 
-  def self.run_unwapper_in_pwd
+  def self.run_unwapper_in_pwd(base_branch:)
     return unless lockfile_present?
 
     puts "Doing the unwrappr thing in #{Dir.pwd}"
 
-    GitCommandRunner.create_branch!
+    GitCommandRunner.create_branch!(base_branch: base_branch)
     BundlerCommandRunner.bundle_update!
     GitCommandRunner.commit_and_push_changes!
     GitHub::Client.make_pull_request!

lib/unwrappr/git_command_runner.rb

@@ -7,9 +7,9 @@ module Unwrappr
   # Runs Git commands
   module GitCommandRunner
     class << self
-      def create_branch!
+      def create_branch!(base_branch:)
         raise 'Not a git working dir' unless git_dir?
-        raise 'failed to create branch' unless branch_created?
+        raise "failed to create branch from '#{base_branch}'" unless branch_created?(base_branch: base_branch)
       end
 
       def commit_and_push_changes!
@@ -50,10 +50,10 @@ def git_dir?
         git_wrap { !current_branch_name.empty? }
       end
 
-      def branch_created?
+      def branch_created?(base_branch:)
         timestamp = Time.now.strftime('%Y%m%d-%H%M').freeze
         git_wrap do
-          git.checkout('origin/master')
+          git.checkout(base_branch) unless base_branch.nil?
           git.branch("auto_bundle_update_#{timestamp}").checkout
         end
       end

spec/lib/unwrappr/git_command_runner_spec.rb

@@ -11,7 +11,8 @@
   end
 
   describe '#create_branch!' do
-    subject(:create_branch!) { described_class.create_branch! }
+    subject(:create_branch!) { described_class.create_branch!(base_branch: base_branch) }
+    let(:base_branch) { 'some_branch' }
 
     before { allow(Time).to receive(:now).and_return(Time.parse('2017-11-01 11:23')) }
 
@@ -27,16 +28,32 @@
 
     context 'Given the current directory is a git repo' do
       before do
-        expect(fake_git).to receive(:current_branch).and_return('master')
-        expect(fake_git).to receive(:checkout).with('origin/master')
+        expect(fake_git).to receive(:current_branch).and_return('main')
+        allow(fake_git).to receive(:checkout)
       end
 
-      it 'checks out a new branch based on origin/master, with a timestamp' do
-        expect(fake_git).to receive(:branch).with('auto_bundle_update_20171101-1123').and_return(fake_git)
+      context 'with a named base branch' do
+        let(:base_branch) { 'origin/main' }
 
-        expect(fake_git).to receive(:checkout).with(no_args)
+        it 'checks out a new branch based on the named branch, with a timestamp' do
+          expect(fake_git).to receive(:branch).with('auto_bundle_update_20171101-1123').and_return(fake_git)
 
-        expect(create_branch!).to be_nil
+          expect(create_branch!).to be_nil
+
+          expect(fake_git).to have_received(:checkout).with('origin/main').once
+        end
+      end
+
+      context 'without a named base branch' do
+        let(:base_branch) { nil }
+
+        it 'checks out a new branch based on the current branch, with a timestamp' do
+          expect(fake_git).to receive(:branch).with('auto_bundle_update_20171101-1123').and_return(fake_git)
+
+          expect(create_branch!).to be_nil
+
+          expect(fake_git).not_to have_received(:checkout).with(nil)
+        end
       end
 
       context 'When there is some failure in creating the branch' do
@@ -47,7 +64,7 @@
         end
 
         specify do
-          expect { create_branch! }.to raise_error(RuntimeError, 'failed to create branch')
+          expect { create_branch! }.to raise_error(RuntimeError, "failed to create branch from 'some_branch'")
         end
       end
     end