Fixes #29385: Add /shrug and /tableflip commands

- Updated DSL to support substitution definitions
- Added substitution definition, inherits from command definition
- Added tabelflip and shrug substitutions to interpret service
- Added support for substitution definitions to the extractor for preview mode.
- Added substitution handling in the interpret service

Signed-off-by: Alex Ives <alex@ives.mn>

9 files changed, 225 insertions, 7 deletions

diff --git a/app/services/quick_actions/interpret_service.rb b/app/services/quick_actions/interpret_service.rb
index 5dc1b91d2c0..c22bf7498bb 100644
--- a/app/services/quick_actions/interpret_service.rb
+++ b/app/services/quick_actions/interpret_service.rb
@@ -4,6 +4,9 @@ module QuickActions
 
     attr_reader :issuable
 
+    SHRUG = '¯\\＿(ツ)＿/¯'.freeze
+    TABLEFLIP = '(╯°□°)╯︵ ┻━┻'.freeze
+
     # Takes a text and interprets the commands that are extracted from it.
     # Returns the content without commands, and hash of changes to be applied to a record.
     def execute(content, issuable)
@@ -14,6 +17,7 @@ module QuickActions
 
       content, commands = extractor.extract_commands(content, context)
       extract_updates(commands, context)
+
       [content, @updates]
     end
 
@@ -423,6 +427,18 @@ module QuickActions
       @updates[:spend_time] = { duration: :reset, user: current_user }
     end
 
+    desc "Append the comment with #{SHRUG}"
+    params '<Comment>'
+    substitution :shrug do |comment|
+      "#{comment} #{SHRUG}"
+    end
+
+    desc "Append the comment with #{TABLEFLIP}"
+    params '<Comment>'
+    substitution :tableflip do |comment|
+      "#{comment} #{TABLEFLIP}"
+    end
+
     # This is a dummy command, so that it appears in the autocomplete commands
     desc 'CC'
     params '@user'
diff --git a/changelogs/unreleased/29385-add_shrug_command.yml b/changelogs/unreleased/29385-add_shrug_command.yml
new file mode 100644
index 00000000000..14b8f486d5c
--- /dev/null
+++ b/changelogs/unreleased/29385-add_shrug_command.yml
@@ -0,0 +1,4 @@
+---
+title: Add /shrug and /tableflip commands
+merge_request: 10068
+author: Alex Ives
diff --git a/lib/gitlab/quick_actions/dsl.rb b/lib/gitlab/quick_actions/dsl.rb
index a4a97236ffc..536765305e1 100644
--- a/lib/gitlab/quick_actions/dsl.rb
+++ b/lib/gitlab/quick_actions/dsl.rb
@@ -105,9 +105,32 @@ module Gitlab
         #     # Awesome code block
         #   end
         def command(*command_names, &block)
+          define_command(CommandDefinition, *command_names, &block)
+        end
+
+        # Registers a new substitution which is recognizable from body of email or
+        # comment.
+        # It accepts aliases and takes a block with the formatted content.
+        #
+        # Example:
+        #
+        #   command :my_substitution, :alias_for_my_substitution do |text|
+        #     "#{text} MY AWESOME SUBSTITUTION"
+        #   end
+        def substitution(*substitution_names, &block)
+          define_command(SubstitutionDefinition, *substitution_names, &block)
+        end
+
+        def definition_by_name(name)
+          command_definitions_by_name[name.to_sym]
+        end
+
+        private
+
+        def define_command(klass, *command_names, &block)
           name, *aliases = command_names
 
-          definition = CommandDefinition.new(
+          definition = klass.new(
             name,
             aliases: aliases,
             description: @description,
@@ -130,10 +153,6 @@ module Gitlab
           @condition_block = nil
           @parse_params_block = nil
         end
-
-        def definition_by_name(name)
-          command_definitions_by_name[name.to_sym]
-        end
       end
     end
   end
diff --git a/lib/gitlab/quick_actions/extractor.rb b/lib/gitlab/quick_actions/extractor.rb
index 09576be7156..3ebfa3bd4b8 100644
--- a/lib/gitlab/quick_actions/extractor.rb
+++ b/lib/gitlab/quick_actions/extractor.rb
@@ -46,6 +46,8 @@ module Gitlab
           end
         end
 
+        content, commands = perform_substitutions(content, commands)
+
         [content.strip, commands]
       end
 
@@ -110,6 +112,26 @@ module Gitlab
         }mx
       end
 
+      def perform_substitutions(content, commands)
+        return unless content
+
+        substitution_definitions = self.command_definitions.select do |definition|
+          definition.is_a?(Gitlab::QuickActions::SubstitutionDefinition)
+        end
+
+        substitution_definitions.each do |substitution|
+          match_data = substitution.match(content)
+          if match_data
+            command = [substitution.name.to_s]
+            command << match_data[1] unless match_data[1].empty?
+            commands << command
+          end
+          content = substitution.perform_substitution(self, content)
+        end
+
+        [content, commands]
+      end
+
       def command_names(opts)
         command_definitions.flat_map do |command|
           next if command.noop?
diff --git a/lib/gitlab/quick_actions/substitution_definition.rb b/lib/gitlab/quick_actions/substitution_definition.rb
new file mode 100644
index 00000000000..032c49ed159
--- /dev/null
+++ b/lib/gitlab/quick_actions/substitution_definition.rb
@@ -0,0 +1,24 @@
+module Gitlab
+  module QuickActions
+    class SubstitutionDefinition < CommandDefinition
+      # noop?=>true means these won't get extracted or removed by Gitlab::QuickActions::Extractor#extract_commands
+      # QuickActions::InterpretService#perform_substitutions handles them separately
+      def noop?
+        true
+      end
+
+      def match(content)
+        content.match %r{^/#{all_names.join('|')} ?(.*)$}
+      end
+
+      def perform_substitution(context, content)
+        return unless content
+
+        all_names.each do |a_name|
+          content.gsub!(%r{/#{a_name} ?(.*)$}, execute_block(action_block, context, '\1'))
+        end
+        content
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/quick_actions/dsl_spec.rb b/spec/lib/gitlab/quick_actions/dsl_spec.rb
index a4bb3f911d7..ff59dc48bcb 100644
--- a/spec/lib/gitlab/quick_actions/dsl_spec.rb
+++ b/spec/lib/gitlab/quick_actions/dsl_spec.rb
@@ -42,13 +42,18 @@ describe Gitlab::QuickActions::Dsl do
       command :with_params_parsing do |parsed|
         parsed
       end
+
+      params '<Comment>'
+      substitution :something do |text|
+        "#{text} Some complicated thing you want in here"
+      end
     end
   end
 
   describe '.command_definitions' do
     it 'returns an array with commands definitions' do
       no_args_def, explanation_with_aliases_def, dynamic_description_def,
-      cc_def, cond_action_def, with_params_parsing_def =
+      cc_def, cond_action_def, with_params_parsing_def, substitution_def =
         DummyClass.command_definitions
 
       expect(no_args_def.name).to eq(:no_args)
@@ -104,6 +109,15 @@ describe Gitlab::QuickActions::Dsl do
       expect(with_params_parsing_def.condition_block).to be_nil
       expect(with_params_parsing_def.action_block).to be_a_kind_of(Proc)
       expect(with_params_parsing_def.parse_params_block).to be_a_kind_of(Proc)
+
+      expect(substitution_def.name).to eq(:something)
+      expect(substitution_def.aliases).to eq([])
+      expect(substitution_def.description).to eq('')
+      expect(substitution_def.explanation).to eq('')
+      expect(substitution_def.params).to eq(['<Comment>'])
+      expect(substitution_def.condition_block).to be_nil
+      expect(substitution_def.action_block.call('text')).to eq('text Some complicated thing you want in here')
+      expect(substitution_def.parse_params_block).to be_nil
     end
   end
 end
diff --git a/spec/lib/gitlab/quick_actions/extractor_spec.rb b/spec/lib/gitlab/quick_actions/extractor_spec.rb
index 9d32938e155..f7c288f2393 100644
--- a/spec/lib/gitlab/quick_actions/extractor_spec.rb
+++ b/spec/lib/gitlab/quick_actions/extractor_spec.rb
@@ -9,6 +9,11 @@ describe Gitlab::QuickActions::Extractor do
       command(:assign) { }
       command(:labels) { }
       command(:power) { }
+      command(:noop_command)
+      substitution(:substitution) { 'foo' }
+      substitution :shrug do |comment|
+        "#{comment} SHRUG"
+      end
     end.command_definitions
   end
 
@@ -177,6 +182,38 @@ describe Gitlab::QuickActions::Extractor do
       expect(msg).to eq "hello\nworld"
     end
 
+    it 'does not extract noop commands' do
+      msg = %(hello\nworld\n/reopen\n/noop_command)
+      msg, commands = extractor.extract_commands(msg)
+
+      expect(commands).to eq [['reopen']]
+      expect(msg).to eq "hello\nworld\n/noop_command"
+    end
+
+    it 'extracts and performs substitution commands' do
+      msg = %(hello\nworld\n/reopen\n/substitution)
+      msg, commands = extractor.extract_commands(msg)
+
+      expect(commands).to eq [['reopen'], ['substitution']]
+      expect(msg).to eq "hello\nworld\nfoo"
+    end
+
+    it 'extracts and performs substitution commands' do
+      msg = %(hello\nworld\n/reopen\n/shrug this is great?)
+      msg, commands = extractor.extract_commands(msg)
+
+      expect(commands).to eq [['reopen'], ['shrug', 'this is great?']]
+      expect(msg).to eq "hello\nworld\nthis is great? SHRUG"
+    end
+
+    it 'extracts and performs substitution commands with comments' do
+      msg = %(hello\nworld\n/reopen\n/substitution wow this is a thing.)
+      msg, commands = extractor.extract_commands(msg)
+
+      expect(commands).to eq [['reopen'], ['substitution', 'wow this is a thing.']]
+      expect(msg).to eq "hello\nworld\nfoo"
+    end
+
     it 'extracts multiple commands' do
       msg = %(hello\n/power @user.name %9.10 ~"bar baz.2" label\nworld\n/reopen)
       msg, commands = extractor.extract_commands(msg)
diff --git a/spec/lib/gitlab/quick_actions/substitution_definition_spec.rb b/spec/lib/gitlab/quick_actions/substitution_definition_spec.rb
new file mode 100644
index 00000000000..1bb8bc51c96
--- /dev/null
+++ b/spec/lib/gitlab/quick_actions/substitution_definition_spec.rb
@@ -0,0 +1,42 @@
+require 'spec_helper'
+
+describe Gitlab::QuickActions::SubstitutionDefinition do
+  let(:content) do
+    <<EOF
+Hello! Let's do this!
+/sub_name I like this stuff
+EOF
+  end
+  subject do
+    described_class.new(:sub_name, action_block: proc { |text| "#{text} foo" })
+  end
+
+  describe '#perform_substitution!' do
+    it 'returns nil if content is nil' do
+      expect(subject.perform_substitution(self, nil)).to be_nil
+    end
+
+    it 'performs the substitution by default' do
+      expect(subject.perform_substitution(self, content)).to eq <<EOF
+Hello! Let's do this!
+I like this stuff foo
+EOF
+    end
+  end
+
+  describe '#match' do
+    it 'checks the content for the command' do
+      expect(subject.match(content)).to be_truthy
+    end
+
+    it 'returns the match data' do
+      data = subject.match(content)
+      expect(data).to be_a(MatchData)
+      expect(data[1]).to eq('I like this stuff')
+    end
+
+    it 'is nil if content does not have the command' do
+      expect(subject.match('blah')).to be_falsey
+    end
+  end
+end
diff --git a/spec/services/quick_actions/interpret_service_spec.rb b/spec/services/quick_actions/interpret_service_spec.rb
index 42a4a2591ea..92bde2c92bf 100644
--- a/spec/services/quick_actions/interpret_service_spec.rb
+++ b/spec/services/quick_actions/interpret_service_spec.rb
@@ -9,13 +9,13 @@ describe QuickActions::InterpretService do
   let(:inprogress) { create(:label, project: project, title: 'In Progress') }
   let(:bug) { create(:label, project: project, title: 'Bug') }
   let(:note) { build(:note, commit_id: merge_request.diff_head_sha) }
+  let(:service) { described_class.new(project, developer) }
 
   before do
     project.team << [developer, :developer]
   end
 
   describe '#execute' do
-    let(:service) { described_class.new(project, developer) }
     let(:merge_request) { create(:merge_request, source_project: project) }
 
     shared_examples 'reopen command' do
@@ -270,6 +270,22 @@ describe QuickActions::InterpretService do
       end
     end
 
+    shared_examples 'shrug command' do
+      it 'appends ¯\_(ツ)_/¯ to the comment' do
+        new_content, _ = service.execute(content, issuable)
+
+        expect(new_content).to end_with(described_class::SHRUG)
+      end
+    end
+
+    shared_examples 'tableflip command' do
+      it 'appends (╯°□°)╯︵ ┻━┻ to the comment' do
+        new_content, _ = service.execute(content, issuable)
+
+        expect(new_content).to end_with(described_class::TABLEFLIP)
+      end
+    end
+
     it_behaves_like 'reopen command' do
       let(:content) { '/reopen' }
       let(:issuable) { issue }
@@ -775,6 +791,30 @@ describe QuickActions::InterpretService do
       end
     end
 
+    context '/shrug command' do
+      it_behaves_like 'shrug command' do
+        let(:content) { '/shrug people are people' }
+        let(:issuable) { issue }
+      end
+
+      it_behaves_like 'shrug command' do
+        let(:content) { '/shrug' }
+        let(:issuable) { issue }
+      end
+    end
+
+    context '/tableflip command' do
+      it_behaves_like 'tableflip command' do
+        let(:content) { '/tableflip curse your sudden but enviable betrayal' }
+        let(:issuable) { issue }
+      end
+
+      it_behaves_like 'tableflip command' do
+        let(:content) { '/tableflip' }
+        let(:issuable) { issue }
+      end
+    end
+
     context '/target_branch command' do
       let(:non_empty_project) { create(:project, :repository) }
       let(:another_merge_request) { create(:merge_request, author: developer, source_project: non_empty_project) }