Support stacked PRs for subfeatures

Signed-off-by: Phil Dibowitz <phil@ipom.com>

.rubocop.yml

@@ -9,6 +9,9 @@ AllCops:
 Layout/LineLength:
   Max: 80
 
+Metrics/BlockNesting:
+  Enabled: false
+
 Naming/FileName:
   Enabled: false
 

bin/sj

@@ -99,6 +99,16 @@ parser = OptionParser.new do |opts|
     options['pr_autofill'] = autofill
   end
 
+  opts.on(
+    '--[no-]pr-autostack',
+    'When creating a PR, if this is a subfeature, should we make it a ' +
+    'PR on the PR for the parent feature. If not specified, we prompt ' +
+    'when this happens, when true always do this, when false never do ' +
+    'this. Only applicable when usiing "gh".',
+  ) do |autostack|
+    options['pr_autofill'] = autostack
+  end
+
   opts.on('--[no-]use-color', 'Enable color. [default: true]') do |color|
     options['color'] = color
   end

lib/sugarjar/commands.rb

@@ -24,6 +24,7 @@ def initialize(options)
       SugarJar::Log.debug("Repoconfig: #{@repo_config}")
       @color = options['color']
       @pr_autofill = options['pr_autofill']
+      @pr_autostack = options['pr_autostack']
       @feature_prefix = options['feature_prefix']
       @checks = {}
       @main_branch = nil
@@ -330,9 +331,9 @@ def smartpullrequest(*args)
       end
 
       if gh?
+        curr = current_branch
+        base = tracked_branch
         if @pr_autofill
-          curr = current_branch
-          base = tracked_branch
           num_commits = git(
             'rev-list', '--count', curr, "^#{base}"
           ).stdout.strip.to_i
@@ -345,6 +346,19 @@ def smartpullrequest(*args)
             args.unshift('--fill')
           end
         end
+        if looks_stacked?(base)
+          # nil is prompt, true is always, false is never
+          if @pr_autostack.nil?
+            $stdout.print(
+              'It looks like this is a subfeature, would you like to base ' +
+              "this PR on #{base}? [y/n] ",
+            )
+            ans = $stdin.gets.strip
+            args += ['--base', base] if %w{Y y}.include?(ans)
+          elsif @pr_autostack
+            args += ['--base', base]
+          end
+        end
         SugarJar::Log.trace("Running: gh pr create #{args.join(' ')}")
         system(which('gh'), 'pr', 'create', *args)
       else
@@ -857,6 +871,12 @@ def gitup
       }
     end
 
+    # determine if this branch is based on another local branch (i.e. is a
+    # subfeature). Used to figure out of we should stack the PR
+    def subfeature?(base)
+      all_local_branches.reject { |x| x == most_main }.include?(base)
+    end
+
     def rebase_in_progress?
       # for rebase without -i
       rebase_file = git('rev-parse', '--git-path', 'rebase-apply').stdout.strip

lib/sugarjar/config.rb

@@ -10,6 +10,7 @@ class Config
       'github_user' => ENV.fetch('USER'),
       'fallthru' => true,
       'pr_autofill' => true,
+      'pr_autostack' => nil,
     }.freeze
 
     def self._find_ordered_files