Module: RatatuiRuby::TestHelper::StyleAssertions

Included in:
RatatuiRuby::TestHelper
Defined in:
lib/ratatui_ruby/test_helper/style_assertions.rb

Overview

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

– SPDX-SnippetBegin SPDX-FileCopyrightText: 2026 Kerrick Long SPDX-License-Identifier: MIT-0 ++

# 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)

– SPDX-SnippetEnd ++

Instance Method Summary collapse

Instance Method Details

#assert_area_style(area, **attributes) ⇒ Object

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

Examples

– SPDX-SnippetBegin SPDX-FileCopyrightText: 2026 Kerrick Long SPDX-License-Identifier: MIT-0 ++

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)

– SPDX-SnippetEnd ++

area

Rect-like object or Hash with x, y, width/w, height/h.

attributes

Style attributes to verify.



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# 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

#assert_bg_color(expected, x, y) ⇒ Object Also known as: assert_bg

Asserts the background color at a coordinate.

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

Example

– SPDX-SnippetBegin SPDX-FileCopyrightText: 2026 Kerrick Long SPDX-License-Identifier: MIT-0 ++

assert_bg_color(:blue, 0, 2)

– SPDX-SnippetEnd ++

expected

Symbol, Integer, or String (hex).

x

Integer x-coordinate.

y

Integer y-coordinate.



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# 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

#assert_bold(x, y) ⇒ Object

Asserts that a cell has the bold modifier.

Example

– SPDX-SnippetBegin SPDX-FileCopyrightText: 2026 Kerrick Long SPDX-License-Identifier: MIT-0 ++

assert_bold(0, 2)

– SPDX-SnippetEnd ++

x

Integer x-coordinate.

y

Integer y-coordinate.



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# 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

#assert_cell_style(x, y, **expected_attributes) ⇒ Object

Asserts that a cell has the expected style attributes.

Example

– SPDX-SnippetBegin SPDX-FileCopyrightText: 2026 Kerrick Long SPDX-License-Identifier: MIT-0 ++

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

– SPDX-SnippetEnd ++

x

Integer x-coordinate.

y

Integer y-coordinate.

expected_attributes

Hash of attribute names to expected values.



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# 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

#assert_color(expected, x:, y:, layer: :fg) ⇒ Object

Asserts foreground or background color at a coordinate.

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

Examples

– SPDX-SnippetBegin SPDX-FileCopyrightText: 2026 Kerrick Long SPDX-License-Identifier: MIT-0 ++

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

– SPDX-SnippetEnd ++

expected

Symbol, Integer, or String (hex).

x

Integer x-coordinate.

y

Integer y-coordinate.

layer

:fg (default) or :bg.



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# 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

#assert_crossed_out(x, y) ⇒ Object Also known as: assert_strikethrough, assert_strike

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

Example

– SPDX-SnippetBegin SPDX-FileCopyrightText: 2026 Kerrick Long SPDX-License-Identifier: MIT-0 ++

assert_crossed_out(0, 2)

– SPDX-SnippetEnd ++

x

Integer x-coordinate.

y

Integer y-coordinate.



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# 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

#assert_dim(x, y) ⇒ Object

Asserts that a cell has the dim modifier.

Example

– SPDX-SnippetBegin SPDX-FileCopyrightText: 2026 Kerrick Long SPDX-License-Identifier: MIT-0 ++

assert_dim(0, 2)

– SPDX-SnippetEnd ++

x

Integer x-coordinate.

y

Integer y-coordinate.



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# 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

#assert_fg_color(expected, x, y) ⇒ Object Also known as: assert_fg

Asserts the foreground color at a coordinate.

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

Example

– SPDX-SnippetBegin SPDX-FileCopyrightText: 2026 Kerrick Long SPDX-License-Identifier: MIT-0 ++

assert_fg_color(:yellow, 0, 2)

– SPDX-SnippetEnd ++

expected

Symbol, Integer, or String (hex).

x

Integer x-coordinate.

y

Integer y-coordinate.



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# 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

#assert_hidden(x, y) ⇒ Object

Asserts that a cell has the hidden modifier.

x

Integer x-coordinate.

y

Integer y-coordinate.



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# 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

#assert_italic(x, y) ⇒ Object

Asserts that a cell has the italic modifier.

Example

– SPDX-SnippetBegin SPDX-FileCopyrightText: 2026 Kerrick Long SPDX-License-Identifier: MIT-0 ++

assert_italic(0, 2)

– SPDX-SnippetEnd ++

x

Integer x-coordinate.

y

Integer y-coordinate.



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# 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

#assert_rapid_blink(x, y) ⇒ Object

Asserts that a cell has the rapid_blink modifier.

x

Integer x-coordinate.

y

Integer y-coordinate.



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# 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

#assert_reversed(x, y) ⇒ Object Also known as: assert_inverse, assert_inverse_video

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

Example

– SPDX-SnippetBegin SPDX-FileCopyrightText: 2026 Kerrick Long SPDX-License-Identifier: MIT-0 ++

assert_reversed(0, 2)

– SPDX-SnippetEnd ++

x

Integer x-coordinate.

y

Integer y-coordinate.



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# 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

#assert_slow_blink(x, y) ⇒ Object Also known as: assert_blink

Asserts that a cell has the slow_blink modifier.

x

Integer x-coordinate.

y

Integer y-coordinate.



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# 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

#assert_underlined(x, y) ⇒ Object Also known as: assert_underline

Asserts that a cell has the underlined modifier.

Example

– SPDX-SnippetBegin SPDX-FileCopyrightText: 2026 Kerrick Long SPDX-License-Identifier: MIT-0 ++

assert_underlined(0, 2)

– SPDX-SnippetEnd ++

x

Integer x-coordinate.

y

Integer y-coordinate.



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# 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