Class: TUITD::Driver

Inherits:
Object
  • Object
show all
Defined in:
lib/tui_td/driver.rb

Overview

Drives a TUI application in a pseudo-terminal (PTY).

Usage:

driver = Driver.new("my_tui_app")
driver.start
driver.wait_for_text("> ")
driver.send("Write hello\n")
state = driver.state_json  # => structured JSON for AI
driver.screenshot("out.png")
driver.close

Constant Summary collapse

FORBIDDEN_ENV = 
%w[PATH LD_PRELOAD LD_LIBRARY_PATH DYLD_INSERT_LIBRARIES
DYLD_FRAMEWORK_PATH RUBYOPT HOME RUBYLIB GEM_HOME GEM_PATH].freeze
MAX_BUFFER_SIZE =

10 MB ring buffer

10 * 1024 * 1024

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(command, rows: 40, cols: 120, timeout: 30, chdir: nil, env: {}, poll_interval: nil) ⇒ Driver

Returns a new instance of Driver.



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# File 'lib/tui_td/driver.rb', line 31

def initialize(command, rows: 40, cols: 120, timeout: 30, chdir: nil, env: {}, poll_interval: nil)
  @command = command
  @rows = rows
  @cols = cols
  @timeout = timeout
  @chdir = chdir
  @env = sanitize_env(env)
  @state = nil
  @stdin = nil
  @stdout = nil
  @wait_thr = nil
  @output_buffer = +""
  @output_mutex = Mutex.new
  @reader_thread = nil
  @reader_running = false
  @poll_interval = poll_interval
end

Instance Attribute Details

#command ⇒ Object (readonly)

Returns the value of attribute command.



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# File 'lib/tui_td/driver.rb', line 27

def command
  @command
end

#state ⇒ Object (readonly)

Returns the value of attribute state.



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# File 'lib/tui_td/driver.rb', line 27

def state
  @state
end

Instance Method Details

#close ⇒ Object

Close the driver and clean up



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# File 'lib/tui_td/driver.rb', line 215

def close
  _stop_reader_thread

  # Kill the process if still running
  if @pid
    begin
      if Process.waitpid(@pid, Process::WNOHANG).nil?
        begin
          Process.kill("TERM", @pid)
        rescue StandardError
          nil
        end
        sleep 0.05
        begin
          Process.kill("KILL", @pid)
        rescue StandardError
          nil
        end
      end
    rescue Errno::ECHILD
      # Already reaped by Process.detach
    end
  end
  begin
    @stdin&.close
  rescue StandardError
    nil
  end
  begin
    @stdout&.close
  rescue StandardError
    nil
  end
  @stdin = @stdout = @pid = nil
end

#exitstatus ⇒ Object

Get the process exit status (nil if still running)



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# File 'lib/tui_td/driver.rb', line 174

def exitstatus
  return nil unless @wait_thr

  status = @wait_thr.value
  status&.exitstatus
rescue NoMethodError
  nil
end

#raw_output ⇒ Object

Get the terminal output (raw ANSI + text)



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# File 'lib/tui_td/driver.rb', line 184

def raw_output
  read_available!
  @output_mutex.synchronize { @output_buffer.dup }
end

#refresh ⇒ Object

Refresh the terminal state by re-parsing the output buffer. Call this if the terminal content has changed and you need an up-to-date state.



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# File 'lib/tui_td/driver.rb', line 191

def refresh
  refresh_state!
  @state
end

#screenshot(output_path) ⇒ Object

Capture a PNG screenshot of the current terminal state



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# File 'lib/tui_td/driver.rb', line 209

def screenshot(output_path)
  state_data
  Screenshot.new(@state).render(output_path)
end

#send(text) ⇒ Object

Send text to the TUI



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# File 'lib/tui_td/driver.rb', line 71

def send(text)
  ensure_running!
  @stdin&.print(text)
  @stdin&.flush
  true
end

#send_keys(keys) ⇒ Object

Send keys (escape sequences, control characters)



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# File 'lib/tui_td/driver.rb', line 79

def send_keys(keys)
  ensure_running!
  case keys
  when :enter then send("\r")
  when :tab   then send("\t")
  when :escape then send("\e")
  when :up    then send("\e[A")
  when :down  then send("\e[B")
  when :left  then send("\e[D")
  when :right then send("\e[C")
  when :backspace then send("\u007f")
  when :ctrl_c then send("\u0003")
  when :ctrl_d then send("\u0004")
  when :page_up   then send("\e[5~")
  when :page_down then send("\e[6~")
  else send(keys.to_s)
  end
end

#start ⇒ Object

Start the TUI application in a PTY



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# File 'lib/tui_td/driver.rb', line 50

def start
  env = { "TERM" => "xterm-256color", "COLUMNS" => @cols.to_s,
          "LINES" => @rows.to_s, }.merge(@env.transform_keys(&:to_s))
  spawn_opts = {}
  spawn_opts[:chdir] = @chdir if @chdir

  cmd_args = Shellwords.shellsplit(@command)
  @stdout, @stdin, @pid = PTY.spawn(env, *cmd_args, spawn_opts)
  @stdout.winsize = [@rows, @cols] # Set PTY window size for TUIs that check winsize
  @wait_thr = Process.detach(@pid)

  # Read until initial output stabilizes
  wait_for_stable
  refresh_state!

  _start_reader_thread

  true
end

#state_data ⇒ Object

Get structured terminal state as a Hash



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# File 'lib/tui_td/driver.rb', line 197

def state_data
  refresh_state!
  @state
end

#state_json(pretty: false) ⇒ Object

Get structured terminal state as JSON string



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# File 'lib/tui_td/driver.rb', line 203

def state_json(pretty: false)
  state_data
  pretty ? JSON.pretty_generate(@state) : JSON.generate(@state)
end

#wait_for(timeout: nil, &predicate) ⇒ Object

Wait until the predicate returns true for the current terminal state. Polls with adaptive intervals: 10ms → 25ms → 50ms → 100ms. Use a custom poll_interval to bypass adaptive behavior.

driver.wait_for { |state| state.find_text("Ready").any? }
driver.wait_for(timeout: 5) { |state| state.foreground_at(0, 0) == "green" }



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# File 'lib/tui_td/driver.rb', line 105

def wait_for(timeout: nil, &predicate)
  deadline = monotonic + (timeout || @timeout)
  loop_count = 0
  loop do
    raise TimeoutError, "Timeout waiting for predicate" if monotonic > deadline

    read_available!
    refresh_state!
    state_obj = State.new(@state)
    break if predicate.call(state_obj)

    adaptive_sleep(loop_count)
    loop_count += 1
  end
  @state
end

#wait_for_exit ⇒ Object

Wait until the process finishes



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# File 'lib/tui_td/driver.rb', line 169

def wait_for_exit
  @wait_thr&.value
end

#wait_for_stable(stable_ms: 300) ⇒ Object

Wait for output to stabilize (grid content unchanged for N milliseconds)



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# File 'lib/tui_td/driver.rb', line 140

def wait_for_stable(stable_ms: 300)
  deadline = monotonic + @timeout
  last_change = monotonic
  last_buffer_size = @output_mutex.synchronize { @output_buffer.bytesize }
  loop_count = 0

  loop do
    raise TimeoutError, "Timeout waiting for stable output" if monotonic > deadline

    read_available!
    current_buffer_size = @output_mutex.synchronize { @output_buffer.bytesize }
    process_alive = process_alive?

    if current_buffer_size != last_buffer_size
      last_buffer_size = current_buffer_size
      last_change = monotonic
    elsif !process_alive
      break
    elsif (monotonic - last_change) * 1000 >= stable_ms # rubocop:disable Lint/DuplicateBranch
      break
    end

    adaptive_sleep(loop_count)
    loop_count += 1
  end
  refresh_state!
end

#wait_for_text(text) ⇒ Object

Wait until output contains the given text



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# File 'lib/tui_td/driver.rb', line 123

def wait_for_text(text)
  deadline = monotonic + @timeout
  loop_count = 0
  loop do
    raise TimeoutError, "Timeout waiting for: #{text.inspect}" if monotonic > deadline

    read_available!
    found = @output_mutex.synchronize { @output_buffer.include?(text) }
    break if found

    adaptive_sleep(loop_count)
    loop_count += 1
  end
  refresh_state!
end