Class: Charming::Internal::Terminal::MemoryBackend

Inherits:
Object
  • Object
show all
Includes:
Adapter
Defined in:
lib/charming/internal/terminal/memory_backend.rb

Overview

MemoryBackend is an in-memory implementation of the terminal Adapter used by RSpec specs. It serves events from a fixed events: list and records every output operation in frames (rendered output) and operations (every method call with its arguments), so tests can assert against observed output.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(events: [], width: 80, height: 24) ⇒ MemoryBackend

events is the queue of pre-seeded events to return from read_event. width/height set the initial terminal dimensions reported by size.



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 24

def initialize(events: [], width: 80, height: 24)
  @events = events.dup
  @width = width
  @height = height
  @frames = []
  @operations = []
  @escapes = []
  @mouse_enabled = false
end

Instance Attribute Details

#escapes ⇒ Object (readonly)

The array of out-of-band escape sequences written via write_escape.



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 20

def escapes
  @escapes
end

#frames ⇒ Object (readonly)

The array of rendered frame strings (one per write_frame or write_lines call).



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 14

def frames
  @frames
end

#operations ⇒ Object (readonly)

The array of recorded operation tuples: [:method_name, *args].



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 17

def operations
  @operations
end

Instance Method Details

#clear ⇒ Object

Records a clear-screen operation.



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 96

def clear
  @operations << :clear
end

#disable_mouse_tracking ⇒ Object

Marks the backend as having mouse tracking disabled and records the operation.



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 118

def disable_mouse_tracking
  @mouse_enabled = false
  @operations << :disable_mouse_tracking
end

#enable_mouse_tracking(motion: :drag) ⇒ Object

Marks the backend as having mouse tracking enabled and records the operation with the requested motion mode (:drag or :all).



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 112

def enable_mouse_tracking(motion: :drag)
  @mouse_enabled = true
  @operations << [:enable_mouse_tracking, motion]
end

#enter_alt_screen ⇒ Object

Records an enter-alt-screen operation.



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 76

def enter_alt_screen
  @operations << :enter_alt_screen
end

#exhausted? ⇒ Boolean

True when every pre-seeded event has been consumed. The Runtime stops its loop on an exhausted backend so tests can't hang waiting for input that never comes.

Returns:

  • (Boolean) 


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# File 'lib/charming/internal/terminal/memory_backend.rb', line 42

def exhausted?
  @events.empty?
end

#hide_cursor ⇒ Object

Records a hide-cursor operation.



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 91

def hide_cursor
  @operations << :hide_cursor
end

#input_pending? ⇒ Boolean

True when a pre-seeded event is still queued (mirrors a TTY with bytes ready). Lets the runtime's held-key coalescing drain seeded repeats in specs.

Returns:

  • (Boolean) 


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# File 'lib/charming/internal/terminal/memory_backend.rb', line 48

def input_pending?
  !@events.empty?
end

#leave_alt_screen ⇒ Object

Records a leave-alt-screen operation.



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 81

def leave_alt_screen
  @operations << :leave_alt_screen
end

#mouse_enabled? ⇒ Boolean

Returns whether mouse tracking is currently enabled.

Returns:

  • (Boolean) 


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# File 'lib/charming/internal/terminal/memory_backend.rb', line 124

def mouse_enabled?
  @mouse_enabled
end

#move_cursor(row, column) ⇒ Object

Records a move-cursor operation at the given (row, column) (1-based).



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 101

def move_cursor(row, column)
  @operations << [:move_cursor, row, column]
end

#read_event(timeout: nil) ⇒ Object

Pops the next pre-seeded event from the queue. Returns nil when the queue is empty.



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 35

def read_event(timeout: nil)
  @operations << [:read_event, timeout]
  @events.shift
end

#show_cursor ⇒ Object

Records a show-cursor operation.



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 86

def show_cursor
  @operations << :show_cursor
end

#size ⇒ Object

Returns the configured terminal dimensions as [width, height].



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 106

def size
  [@width, @height]
end

#write_escape(sequence) ⇒ Object

Records an out-of-band escape sequence, appending it to escapes and recording the operation (so specs can assert both its content and its ordering relative to frames).



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 70

def write_escape(sequence)
  @escapes << sequence
  @operations << [:write_escape, sequence]
end

#write_frame(frame) ⇒ Object

Stores frame as the current frame and appends it to frames.



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 53

def write_frame(frame)
  @current_frame = frame
  @frames << frame
  @operations << [:write_frame, frame]
end

#write_lines(line_changes, frame: nil) ⇒ Object

Applies the [row, line] line_changes to the current frame, then stores and records the result. The full frame is taken from the optional frame: argument (when provided) or built by overlaying the changes on the previous frame.



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# File 'lib/charming/internal/terminal/memory_backend.rb', line 62

def write_lines(line_changes, frame: nil)
  @current_frame = frame || apply_line_changes(line_changes)
  @frames << @current_frame
  @operations << [:write_lines, line_changes]
end