module RatatuiRuby::TestHelper::StyleAssertions

Assertions for verifying cell-level styling in terminal UIs.

TUI styling is invisible to plain text comparisons. Colors, bold, italic, and other modifiers define the visual hierarchy. Without style assertions, you cannot verify that your highlight is actually highlighted.

This mixin provides assertions to check foreground, background, and modifiers at specific coordinates or across entire regions.

Use it to verify selection highlights, error colors, or themed areas.

Examples

# Single cell
assert_cell_style(0, 0, fg: :red, modifiers: [:bold])

# Foreground color at coordinate
assert_color(:green, x: 5, y: 2)

# Entire header region
assert_area_style({ x: 0, y: 0, w: 80, h: 1 }, bg: :blue)

Public Instance Methods

assert_area_style (area, **attributes)

Source

# File lib/ratatui_ruby/test_helper/style_assertions.rb, line 130
def assert_area_style(area, **attributes)
  if area.is_a?(Hash)
    x = area[:x] || 0
    y = area[:y] || 0
    w = area[:width] || area[:w] || 0
    h = area[:height] || area[:h] || 0
  else
    x = area.x
    y = area.y
    w = area.width
    h = area.height
  end

  (y...(y + h)).each do |row|
    (x...(x + w)).each do |col|
      assert_cell_style(col, row, **attributes)
    end
  end
end

Asserts that all cells in an area have the expected style.

Examples

header = RatatuiRuby::Layout::Rect.new(x: 0, y: 0, width: 80, height: 1)
assert_area_style(header, bg: :blue, modifiers: [:bold])

assert_area_style({ x: 0, y: 0, w: 10, h: 1 }, fg: :red)

area: Rect-like object or Hash with x, y, width/w, height/h.
attributes: Style attributes to verify.

assert_bg (expected, x, y)

Alias for: assert_bg_color

assert_bg_color (expected, x, y)

Source

# File lib/ratatui_ruby/test_helper/style_assertions.rb, line 195
def assert_bg_color(expected, x, y)
  assert_color(expected, x:, y:, layer: :bg)
end

Asserts the background color at a coordinate.

Convenience alias for assert_color(expected, x:, y:, layer: :bg).

Example

assert_bg_color(:blue, 0, 2)

expected: Symbol, Integer, or String (hex).
x: Integer x-coordinate.
y: Integer y-coordinate.

Also aliased as: assert_bg

assert_blink (x, y)

Alias for: assert_slow_blink

assert_bold (x, y)

Source

# File lib/ratatui_ruby/test_helper/style_assertions.rb, line 217
def assert_bold(x, y)
  cell = get_cell(x, y)
  modifiers = (cell.modifiers || []).map(&:to_sym)
  assert modifiers.include?(:bold),
    "Expected cell at (#{x}, #{y}) to be bold, but modifiers were #{modifiers.inspect}"
end

Asserts that a cell has the bold modifier.

Example

assert_bold(0, 2)

x: Integer x-coordinate.
y: Integer y-coordinate.

assert_cell_style (x, y, **expected_attributes)

Source

# File lib/ratatui_ruby/test_helper/style_assertions.rb, line 60
def assert_cell_style(x, y, **expected_attributes)
  cell = get_cell(x, y)
  expected_attributes.each do |key, value|
    actual_value = cell.public_send(key)
    if value.nil?
      assert_nil actual_value, "Expected cell at (#{x}, #{y}) to have #{key}=nil, but got #{actual_value.inspect}"
    else
      assert_equal value, actual_value, "Expected cell at (#{x}, #{y}) to have #{key}=#{value.inspect}, but got #{actual_value.inspect}"
    end
  end
end

Asserts that a cell has the expected style attributes.

Example

assert_cell_style(0, 0, char: "H", fg: :red)

x: Integer x-coordinate.
y: Integer y-coordinate.
expected_attributes: Hash of attribute names to expected values.

assert_color (expected, x:, y:, layer: :fg)

Source

# File lib/ratatui_ruby/test_helper/style_assertions.rb, line 95
def assert_color(expected, x:, y:, layer: :fg)
  cell = get_cell(x, y)
  actual = cell.public_send(layer)

  # Normalize expected integer to symbol if needed (RatatuiRuby returns :indexed_N)
  expected_normalized = if expected.is_a?(Integer)
    :"indexed_#{expected}"
  else
    expected
  end

  assert_equal expected_normalized, actual,
    "Expected #{layer} at (#{x}, #{y}) to be #{expected.inspect}, but got #{actual.inspect}"
end

Asserts foreground or background color at a coordinate.

Accepts symbols (:red), indexed colors (integers), or hex strings.

Examples

assert_color(:red, x: 10, y: 5)
assert_color(5, x: 10, y: 5, layer: :bg)
assert_color("#ff00ff", x: 10, y: 5)

expected: Symbol, Integer, or String (hex).
x: Integer x-coordinate.
y: Integer y-coordinate.
layer: :fg (default) or :bg.

assert_crossed_out (x, y)

Source

# File lib/ratatui_ruby/test_helper/style_assertions.rb, line 340
def assert_crossed_out(x, y)
  cell = get_cell(x, y)
  modifiers = (cell.modifiers || []).map(&:to_sym)
  assert modifiers.include?(:crossed_out),
    "Expected cell at (#{x}, #{y}) to be crossed_out, but modifiers were #{modifiers.inspect}"
end

Asserts that a cell has the crossed_out (strikethrough) modifier.

Example

assert_crossed_out(0, 2)

x: Integer x-coordinate.
y: Integer y-coordinate.

Also aliased as: assert_strikethrough, assert_strike

assert_dim (x, y)

Source

# File lib/ratatui_ruby/test_helper/style_assertions.rb, line 290
def assert_dim(x, y)
  cell = get_cell(x, y)
  modifiers = (cell.modifiers || []).map(&:to_sym)
  assert modifiers.include?(:dim),
    "Expected cell at (#{x}, #{y}) to be dim, but modifiers were #{modifiers.inspect}"
end

Asserts that a cell has the dim modifier.

Example

assert_dim(0, 2)

x: Integer x-coordinate.
y: Integer y-coordinate.

assert_fg (expected, x, y)

Alias for: assert_fg_color

assert_fg_color (expected, x, y)

Source

# File lib/ratatui_ruby/test_helper/style_assertions.rb, line 170
def assert_fg_color(expected, x, y)
  assert_color(expected, x:, y:, layer: :fg)
end

Asserts the foreground color at a coordinate.

Convenience alias for assert_color(expected, x:, y:, layer: :fg).

Example

assert_fg_color(:yellow, 0, 2)

expected: Symbol, Integer, or String (hex).
x: Integer x-coordinate.
y: Integer y-coordinate.

Also aliased as: assert_fg

assert_hidden (x, y)

Source

# File lib/ratatui_ruby/test_helper/style_assertions.rb, line 354
def assert_hidden(x, y)
  cell = get_cell(x, y)
  modifiers = (cell.modifiers || []).map(&:to_sym)
  assert modifiers.include?(:hidden),
    "Expected cell at (#{x}, #{y}) to be hidden, but modifiers were #{modifiers.inspect}"
end

Asserts that a cell has the hidden modifier.

x: Integer x-coordinate.
y: Integer y-coordinate.

assert_inverse (x, y)

Alias for: assert_reversed

assert_inverse_video (x, y)

Alias for: assert_reversed

assert_italic (x, y)

Source

# File lib/ratatui_ruby/test_helper/style_assertions.rb, line 241
def assert_italic(x, y)
  cell = get_cell(x, y)
  modifiers = (cell.modifiers || []).map(&:to_sym)
  assert modifiers.include?(:italic),
    "Expected cell at (#{x}, #{y}) to be italic, but modifiers were #{modifiers.inspect}"
end

Asserts that a cell has the italic modifier.

Example

assert_italic(0, 2)

x: Integer x-coordinate.
y: Integer y-coordinate.

assert_rapid_blink (x, y)

Source

# File lib/ratatui_ruby/test_helper/style_assertions.rb, line 379
def assert_rapid_blink(x, y)
  cell = get_cell(x, y)
  modifiers = (cell.modifiers || []).map(&:to_sym)
  assert modifiers.include?(:rapid_blink),
    "Expected cell at (#{x}, #{y}) to have rapid_blink, but modifiers were #{modifiers.inspect}"
end

Asserts that a cell has the rapid_blink modifier.

x: Integer x-coordinate.
y: Integer y-coordinate.

assert_reversed (x, y)

Source

# File lib/ratatui_ruby/test_helper/style_assertions.rb, line 314
def assert_reversed(x, y)
  cell = get_cell(x, y)
  modifiers = (cell.modifiers || []).map(&:to_sym)
  assert modifiers.include?(:reversed),
    "Expected cell at (#{x}, #{y}) to be reversed, but modifiers were #{modifiers.inspect}"
end

Asserts that a cell has the reversed (inverse video) modifier.

Example

assert_reversed(0, 2)

x: Integer x-coordinate.
y: Integer y-coordinate.

Also aliased as: assert_inverse, assert_inverse_video

assert_slow_blink (x, y)

Source

# File lib/ratatui_ruby/test_helper/style_assertions.rb, line 366
def assert_slow_blink(x, y)
  cell = get_cell(x, y)
  modifiers = (cell.modifiers || []).map(&:to_sym)
  assert modifiers.include?(:slow_blink),
    "Expected cell at (#{x}, #{y}) to have slow_blink, but modifiers were #{modifiers.inspect}"
end

Asserts that a cell has the slow_blink modifier.

x: Integer x-coordinate.
y: Integer y-coordinate.

Also aliased as: assert_blink

assert_strike (x, y)

Alias for: assert_crossed_out

assert_strikethrough (x, y)

Alias for: assert_crossed_out

assert_underline (x, y)

Alias for: assert_underlined

assert_underlined (x, y)

Source

# File lib/ratatui_ruby/test_helper/style_assertions.rb, line 265
def assert_underlined(x, y)
  cell = get_cell(x, y)
  modifiers = (cell.modifiers || []).map(&:to_sym)
  assert modifiers.include?(:underlined),
    "Expected cell at (#{x}, #{y}) to be underlined, but modifiers were #{modifiers.inspect}"
end

Asserts that a cell has the underlined modifier.

Example

assert_underlined(0, 2)

x: Integer x-coordinate.
y: Integer y-coordinate.

Also aliased as: assert_underline