Add agent-backed file processing DSL

2 files changed, 338 insertions, 0 deletions

diff --git a/test/lib/dslkeywords/agent_test.rb b/test/lib/dslkeywords/agent_test.rb
new file mode 100644
index 0000000..5eb5bc5
--- /dev/null
+++ b/test/lib/dslkeywords/agent_test.rb
@@ -0,0 +1,312 @@
+# frozen_string_literal: true
+
+# rubocop:disable Metrics/ClassLength, Metrics/MethodLength
+require 'minitest/autorun'
+require 'fileutils'
+require 'rbconfig'
+require 'shellwords'
+require 'tmpdir'
+
+require_relative '../../../lib/dsl'
+
+class RCMAgentTest < Minitest::Test
+  MOCK_AGENT = File.expand_path('../../support/mock_agent.rb', __dir__).freeze
+
+  def setup
+    @dir_path = Dir.mktmpdir('.agent_test.rcmtmp.')
+    @original_argv = ARGV.dup
+  end
+
+  def teardown
+    ARGV.replace(@original_argv) if @original_argv
+    FileUtils.rm_rf(@dir_path) if @dir_path
+  end
+
+  def path(name)
+    File.join(@dir_path, name)
+  end
+
+  def mock_agent_command(mode, *args)
+    parts = [RbConfig.ruby, MOCK_AGENT, mode.to_s]
+    args.each do |arg|
+      parts << if %w[INPUT PROMPT FILE_PATH].include?(arg)
+                 arg
+               else
+                 Shellwords.escape(arg.to_s)
+               end
+    end
+
+    [Shellwords.escape(parts.shift), Shellwords.escape(parts.shift), Shellwords.escape(parts.shift), *parts].join(' ')
+  end
+
+  def test_duplicate_agent_definition
+    assert_raises(RCM::DSL::DuplicateDefinition) do
+      configure_from_scratch do
+        agent mock do
+          'ruby -e "print STDIN.read"'
+        end
+
+        agent mock do
+          'ruby -e "print STDIN.read"'
+        end
+      end
+    end
+  end
+
+  def test_duplicate_prompt_definition
+    assert_raises(RCM::DSL::DuplicateDefinition) do
+      configure_from_scratch do
+        prompt 'fix english' do
+          'Fix grammar'
+        end
+
+        prompt 'fix english' do
+          'Fix spelling'
+        end
+      end
+    end
+  end
+
+  def test_agent_processes_file_using_stdin_and_names_with_spaces
+    file_path = path('process.txt')
+    command = mock_agent_command(:upcase_prompt, 'PROMPT')
+    File.write(file_path, 'hello world')
+
+    configure_from_scratch do
+      agent mock do
+        command
+      end
+
+      prompt 'fix english' do
+        'Fix grammar'
+      end
+
+      file file_path do
+        agent mock, 'fix english'
+      end
+    end
+
+    assert_equal 'HELLO WORLD|Fix grammar', File.read(file_path)
+  end
+
+  def test_agent_processes_file_using_prompt_name_with_spaces
+    file_path = path('process-spaced-prompt.txt')
+    command = mock_agent_command(:upcase_prompt, 'PROMPT')
+    File.write(file_path, 'hello world')
+
+    configure_from_scratch do
+      agent mock do
+        command
+      end
+
+      prompt fix english do
+        'Fix grammar'
+      end
+
+      file file_path do
+        agent mock fix english
+      end
+    end
+
+    assert_equal 'HELLO WORLD|Fix grammar', File.read(file_path)
+  end
+
+  def test_agent_can_use_input_placeholder
+    file_path = path('input.txt')
+    command = mock_agent_command(:reverse_input, 'INPUT')
+    File.write(file_path, 'abc123')
+
+    configure_from_scratch do
+      agent 'reverse via file' do
+        command
+      end
+
+      prompt 'no op' do
+        ''
+      end
+
+      file file_path do
+        agent 'reverse via file', 'no op'
+      end
+    end
+
+    assert_equal '321cba', File.read(file_path)
+  end
+
+  def test_agent_can_use_file_path_placeholder
+    file_path = path('placeholder.txt')
+    command = mock_agent_command(:basename, 'FILE_PATH')
+    File.write(file_path, 'ignored')
+
+    configure_from_scratch do
+      agent 'show file name' do
+        command
+      end
+
+      prompt 'no op' do
+        ''
+      end
+
+      file file_path do
+        agent 'show file name', 'no op'
+      end
+    end
+
+    assert_equal 'placeholder.txt', File.read(file_path)
+  end
+
+  def test_agent_processing_skips_backup_when_output_is_unchanged
+    file_path = path('unchanged.txt')
+    command = mock_agent_command(:pass_through)
+    File.write(file_path, 'same content')
+
+    configure_from_scratch do
+      agent 'pass through' do
+        command
+      end
+
+      prompt 'no op' do
+        ''
+      end
+
+      file file_path do
+        agent 'pass through', 'no op'
+      end
+    end
+
+    backup_dir = File.join(File.dirname(file_path), '.rcmbackup')
+    assert_empty Dir.glob(File.join(backup_dir, 'unchanged.txt.*'))
+    assert_equal 'same content', File.read(file_path)
+  end
+
+  def test_agent_processing_creates_backup_when_output_changes
+    file_path = path('backup.txt')
+    command = mock_agent_command(:upcase)
+    File.write(file_path, 'hello')
+
+    configure_from_scratch do
+      agent 'make loud' do
+        command
+      end
+
+      prompt 'no op' do
+        ''
+      end
+
+      file file_path do
+        agent 'make loud', 'no op'
+      end
+    end
+
+    backup_dir = File.join(@dir_path, '.rcmbackup')
+    assert_equal 'HELLO', File.read(file_path)
+    assert_equal 1, Dir.glob(File.join(backup_dir, 'backup.txt.*')).count
+  end
+
+  def test_unknown_agent_raises
+    file_path = path('unknown-agent.txt')
+    File.write(file_path, 'hello')
+
+    assert_raises(RCM::DSL::NoSuchAgentDefinition) do
+      configure_from_scratch do
+        prompt 'no op' do
+          ''
+        end
+
+        file file_path do
+          agent 'missing agent', 'no op'
+        end
+      end
+    end
+  end
+
+  def test_unknown_prompt_raises
+    file_path = path('unknown-prompt.txt')
+    command = mock_agent_command(:pass_through)
+    File.write(file_path, 'hello')
+
+    assert_raises(RCM::DSL::NoSuchPromptDefinition) do
+      configure_from_scratch do
+        agent mock do
+          command
+        end
+
+        file file_path do
+          agent mock, 'missing prompt'
+        end
+      end
+    end
+  end
+
+  def test_missing_agent_input_raises
+    file_path = path('missing.txt')
+    command = mock_agent_command(:pass_through)
+    refute File.exist?(file_path)
+
+    assert_raises(RCM::File::MissingAgentInput) do
+      configure_from_scratch do
+        agent mock do
+          command
+        end
+
+        prompt 'no op' do
+          ''
+        end
+
+        file file_path do
+          agent mock, 'no op'
+        end
+      end
+    end
+  end
+
+  def test_dry_run_does_not_execute_agent
+    file_path = path('dry-run.txt')
+    command = mock_agent_command(:fail, 'boom', '7')
+    File.write(file_path, 'keep me')
+    ARGV.replace(['--dry'])
+
+    configure_from_scratch do
+      agent 'should not run' do
+        command
+      end
+
+      prompt 'no op' do
+        ''
+      end
+
+      file file_path do
+        agent 'should not run', 'no op'
+      end
+    end
+
+    assert_equal 'keep me', File.read(file_path)
+  end
+
+  def test_non_zero_exit_raises
+    file_path = path('broken.txt')
+    command = mock_agent_command(:fail, 'boom', '7')
+    File.write(file_path, 'hello')
+
+    error = assert_raises(RCM::File::AgentCommandFailed) do
+      configure_from_scratch do
+        agent 'broken agent' do
+          command
+        end
+
+        prompt 'no op' do
+          ''
+        end
+
+        file file_path do
+          agent 'broken agent', 'no op'
+        end
+      end
+    end
+
+    assert_match('exit 7', error.message)
+    assert_match('boom', error.message)
+  end
+end
+
+# rubocop:enable Metrics/ClassLength, Metrics/MethodLength
diff --git a/test/support/mock_agent.rb b/test/support/mock_agent.rb
new file mode 100644
index 0000000..b86de4f
--- /dev/null
+++ b/test/support/mock_agent.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+mode = ARGV.shift.to_s
+stdin = $stdin.read
+
+case mode
+when 'upcase_prompt'
+  prompt = ARGV.fetch(0, '')
+  print "#{stdin.upcase}|#{prompt}"
+when 'reverse_input'
+  input_path = ARGV.fetch(0)
+  print File.read(input_path).reverse
+when 'basename'
+  file_path = ARGV.fetch(0)
+  print File.basename(file_path)
+when 'pass_through'
+  print stdin
+when 'upcase'
+  print stdin.upcase
+when 'fail'
+  warn ARGV.fetch(0, 'boom')
+  exit Integer(ARGV.fetch(1, '7'))
+else
+  warn "unknown mode: #{mode}"
+  exit 2
+end