Test Unit using float multiplier

Improve string randomization. Use Capybara table selectors.

config/initializers/core_ext.rb

@@ -4,6 +4,9 @@ require 'core_ext/range'
 
 ActiveSupport.on_load :action_dispatch_system_test_case do
   prepend CoreExt::ActionDispatch::SystemTesting::TestHelpers::ScreenshotHelperUniqueId
+  # Allow denormalized string comparison,
+  # https://github.com/orgs/teamcapybara/discussions/2841
+  XPath::DSL.prepend CoreExt::XPath::DSL::NormalizeSpaceDefault
 end
 
 ActiveSupport.on_load :action_view do

config/locales/en.yml

@@ -41,6 +41,24 @@ en:
               descendant_reference: cannot be changed to any of descendants
               self_reference: of the quantitiy cannot be the quantity itself
               user_mismatch: has to belong to the same user as quantity
+  activesupport:
+    # Based on: https://github.com/unicode-org/cldr-json/blob/main/cldr-json/cldr-misc-full/main/en/characters.json
+    characters:
+      subsets:
+        # :exemplarCharacters[EN]
+        exemplar: abcdefghijklmnopqrstuvwxyz
+        # :index[EN]
+        index: ABCDEFGHIJKLMNOPQRSTUVWXYZ
+        numbers: 0123456789
+        # :exemplarCharacters[DE, PL] - exemplarCharacters[EN] +
+        #   :index[DE, PL] - :index[EN]
+        auxiliary: äößüĆŁÓŚŹŻąćęłńóśźż
+        # :punctuation* + :numbers* - space - numbers
+        punctuation: >-
+          !\"#%&'()*+,-./:;?@[]{|}~§«°»×‐‑–—‘’‚“”„†‡…‰′″−
+        # :exemplarCharacters[EL] + :index[EL]
+        symbols: αάβγδεέζηήθιίϊΐκλμνξοόπρσςτυύϋΰφχψωώΑΒΓΔΕΖΗΘΙΚΛΜΝΞΟΠΡΣΤΥΦΧΨΩ
+        space: ' '
   actioncontroller:
     exceptions:
       status:

lib/core_ext/x_path/d_s_l/normalize_space_default.rb

@@ -0,0 +1,8 @@
+module CoreExt::XPath::DSL::NormalizeSpaceDefault
+  def normalize_space(...)
+    Capybara.default_normalize_ws ? super : current
+  end
+
+  alias_method :n, :normalize_space
+  alias_method :normalize, :normalize_space
+end

test/application_system_test_case.rb

@@ -1,7 +1,6 @@
 require "test_helper"
 
 class ApplicationSystemTestCase < ActionDispatch::SystemTestCase
-  include ActionView::Helpers::SanitizeHelper
   include ActionView::Helpers::UrlHelper
 
   # NOTE: geckodriver installed with Firefox, ignore incompatibility warning
@@ -33,14 +32,6 @@ class ApplicationSystemTestCase < ActionDispatch::SystemTestCase
                            button.html_safe)
   end
 
-  # Allow skipping interpolations when translating for testing purposes
-  INTERPOLATION_PATTERNS = Regexp.union(I18n.config.interpolation_patterns)
-  def translate(key, **options)
-    translation = options.empty? ? super.split(INTERPOLATION_PATTERNS, 2).first : super
-    sanitize(translation, tags: [])
-  end
-  alias :t :translate
-
   DB_CONFIGS = ActiveRecord::Base.configurations.configs_for(env_name: "test")
   TEST_CONFIGS = Hash.new(DB_CONFIGS.first.name.to_sym)
   class << self
@@ -73,5 +64,43 @@ class ApplicationSystemTestCase < ActionDispatch::SystemTestCase
     end
   end
 
-
+  # This regex has to be only strict enough to properly reconstruct number. It
+  # is not used for format validation.
+  NUMBER = /\A(
+    (?<base>\-?\d[\d\.]*)
+    (×(?<pow>10(?<ws>\s)?(?<exp>(?(<-2>)()|(\-))[\d]+)))?
+      |
+    \g<pow>
+  )\z/x
+  # Finds table cell in current row corresponding to column name given in locator.
+  # Based on Capybara :table and :table_row selectors.
+  Capybara.add_selector(:table_cell, locator_type: [String, Symbol]) do
+    xpath do |locator|
+      column = XPath.string.n.is(locator.to_s)
+      header_xp = XPath.ancestor(:table)[1].descendant(:tr)[1].descendant(:th)[column]
+      position_xp = XPath.position.equals(header_xp.preceding_sibling.count.plus(1))
+      XPath.descendant(:td).where(header_xp.boolean & position_xp)
+    end
+
+    node_filter(:with_value) do |node, expected|
+      value =
+        case expected
+        when Float
+          node.text.match(NUMBER) { |m| "#{m['base'] || '1'}e#{m['exp']&.lstrip}".to_f }
+        else
+          node.text
+        end
+      (expected == value).tap do |result|
+        add_error("Expected value to be #{expected.inspect}" \
+                  " but was #{value.inspect}") unless result
+      end
+    end
+  end
+
+  Capybara.modify_selector(:table_row) do
+    # Beware: filters of #boolean? type are called within different context.
+    node_filter(:with_focus, :boolean) do |node, value|
+      node.has_selector?(':focus') == value
+    end
+  end
 end

test/system/units_test.rb

@@ -21,6 +21,10 @@ class UnitsTest < ApplicationSystemTestCase
     }
   end
 
+  def list_symbols
+    all(:table_cell, column_title(:symbol)).map(&:text)
+  end
+
   test "index" do
     sign_in
     # Wait for the table to appear first, only then check row count.
@@ -39,6 +43,8 @@ class UnitsTest < ApplicationSystemTestCase
 
   test "new and create" do
     sign_in
+    symbols = list_symbols
+
     link_labels.slice!(:new_unit, :new_subunit)
     type, label = link_labels.to_a.sample
     all(:link, exact_text: label).sample.then do |link|
@@ -46,38 +52,50 @@ class UnitsTest < ApplicationSystemTestCase
       link.assert_matches_selector :link, disabled: true
     end
 
-    values = nil
-    within 'tbody > tr:has(input[type=text], textarea)' do
-      assert_selector ':focus'
-
-      maxlength = all(:fillable_field).to_h do |field|
-        [field[:name], field[:maxlength].to_i || 2**16]
+    attributes = [:symbol, :description]
+    attributes << :multiplier if type == :new_subunit
+    within :table_row, {}, with_focus: true do
+      attributes.map! do |name|
+        field = within(:table_cell, column_title(name)) { find(:fillable_field) }
+        value = case name
+                when :symbol
+                  random_string(1..3, 4..field[:maxlength].to_i,
+                                allow_blank: false, except: symbols)
+                when :description
+                  random_string(0, 1..field[:maxlength].to_i)
+                when :multiplier
+                  if rand < 0.5
+                    random_float(min: field[:min].to_f, max: field[:max].to_f)
+                  else
+                    10.0**rand(-15..15)
+                  end
+                end
+        field.fill_in with: value
+        [name, value]
       end
-      values = {
-        symbol: random_string(deep_rand(1..3, 4..maxlength['unit[symbol]']),
-                              except: @user.units.map(&:symbol), allow_blank: false),
-        description: random_string(rand(0..maxlength['unit[description]']))
-      }.with_indifferent_access
-      within :field, 'unit[multiplier]' do |field|
-        values[:multiplier] = random_number(field[:max], field[:step])
-      end if type == :new_subunit
 
-      values.each_pair { |name, value| fill_in "unit[#{name}]", with: value }
-
-      assert_difference ->{ Unit.count }, 1 do
       click_on t('helpers.submit.create')
     end
-    end
+    attributes = attributes.to_h
 
-    assert_selector '.flash.notice',
-      text: t('units.create.success', unit: Unit.last.symbol)
-    within 'tbody' do
+    assert_selector '.flash.notice', exact_text: t('units.create.success',
+                                                   unit: attributes[:symbol])
+    new_symbols = list_symbols
+
+    within :table do
       assert_no_selector :fillable_field
-      assert_selector 'tr', count: @user.units.count
+      assert_equal symbols.length + 1, new_symbols.length
+
+      m = attributes.delete(:multiplier).to_f if type == :new_subunit
+      within :table_row, attributes.transform_keys { |k| column_title(k) } do
+        assert_selector :table_cell, column_title(:multiplier), with_value: m if m
+      end
     end
     assert_no_selector :link, disabled: true,
       exact_text: Regexp.union(link_labels.values)
-    assert_equal values, Unit.last.attributes.slice(*values.keys)
+
+    refresh
+    assert_equal new_symbols, list_symbols
   end
 
   test "create updates view in order" do

test/test_helper.rb

@@ -7,92 +7,46 @@ class ActiveSupport::TestCase
   fixtures :all
 
   include ActionMailer::TestHelper
+  include ActionView::Helpers::SanitizeHelper
   include ActionView::Helpers::TranslationHelper
 
-  # List of categorized Unicode characters:
-  #   * source: http://www.unicode.org/Public/UNIDATA/UnicodeData.txt
-  #   * file format: http://www.unicode.org/L2/L1999/UnicodeData.html
-  #   * select from graphic ranges: L, M, N, P, S, Zs
-  UNICODE_CHARS = [
-    *"\u0020".."\u007E",
-    *"\u00A0".."\u00AC",
-    *"\u00AE".."\u05FF",
-    *"\u0606".."\u061B",
-    *"\u061D".."\u06DC",
-    *"\u06DE".."\u070E",
-    *"\u0710".."\u07FF"
-  ]
-  def random_string(length, except: [], allow_blank: true)
-    # Rails String#blank? is based on [[:space:]] character class (String::BLANK_RE).
-    # Here we use more general class including tabs, cariage returns and newlines.
-    except << /^\p{Space}+$/ unless allow_blank
+  # Allow skipping interpolations when translating for testing purposes
+  INTERPOLATION_PATTERNS = Regexp.union(I18n.config.interpolation_patterns)
+  def translate(key, **options)
+    translation = options.empty? ? super.split(INTERPOLATION_PATTERNS, 2).first : super
+    sanitize(translation, tags: [])
+  end
+  alias :t :translate
+
+  CHARACTER_SET = {exemplar: 5, index: 1, numbers: 3, auxiliary: 1,
+                   punctuation: 1/16r, symbols: 1/16r, space: 1/6r}
+  # Initialize after setting Minitest.seed to ensure reproducibility.
+  def character_set
+    @@character_set ||=
+      CHARACTER_SET.reduce([]) do |chars, (subset, factor)|
+        s = t("activesupport.characters.subsets.#{subset}").chars
+        if factor.is_a?(Rational)
+          elements = factor * chars.length
+          s *= (elements / s.length).ceil
+          chars + s.sample(elements)
+        else
+          chars + s * factor
+        end
+      end
+  end
+
+  def random_string(*length_ranges, allow_blank: true, except: [])
+    length = deep_rand(length_ranges)
+    raise ArgumentError, "Allow blanks for 0 length" if length == 0 && !allow_blank
     begin
-      result = UNICODE_CHARS.sample(length).join
+      result = character_set.sample(length).join
+      # Rails String#blank? is based on [[:space:]] character class (String::BLANK_RE).
+      # Here we use more general class including tabs, carriage returns and newlines.
+      redo if !allow_blank && /^\p{Space}+$/ === result
     end while except.any? { |e| e === result }
     result
   end
 
-  # Range based string generation. Not finished, but saved as a potential
-  # reference for future work. To work properly it needs to sort in collation
-  # order of database.
-  #def random_between(from, to, maxlength)
-  #  # TODO: sort UNICODE_CHARS
-  #  byebug
-  #  result = ''
-  #  maxlength.times do |i|
-  #    case
-  #    when from[i] == to[i]
-  #      result += from[i]
-  #    else
-  #      from_index = UNICODE_CHARS.bsearch_index(from[i] || UNICODE_CHARS[0])
-  #      to_index = UNICODE_CHARS.bsearch_index(to[i])
-  #      index = rand(from_index..to_index)
-  #      case
-  #      when index == from_index
-  #        result += UNICODE_CHARS[index]
-  #        from[i+1..].each_char do |c|
-  #          from_index = UNICODE_CHARS.bsearch_index(from[i])
-  #          index = rand(from_index..UNICODE_CHARS.length-1)
-  #          result += UNICODE_CHARS[index]
-  #          break if index != from_index
-  #        end
-  #        if result == from
-  #          if result.length < maxlength
-  #            result += UNICODE_CHARS.sample
-  #          else
-  #            # TODO: succ result[i..]
-  #            # raise if result == to
-  #          end
-  #        end
-  #        break
-  #      when index == to_index
-  #        result += UNICODE_CHARS[index]
-  #        to[i+1..].each_char do |c|
-  #          to_index = UNICODE_CHARS.bsearch_index(to[i])
-  #          index = rand(-1..to_index)
-  #          break if index == -1
-  #          result += UNICODE_CHARS[index]
-  #          break if index != to_index
-  #        end
-  #        if result == to
-  #          if result.length > i+1
-  #            result = result[..-2]
-  #          else
-  #            # TODO: prev result[i..]
-  #            # raise if result == from
-  #          end
-  #        end
-  #        break
-  #      else
-  #        result += UNICODE_CHARS[index]
-  #        break
-  #      end
-  #    end
-  #  end
-  #  return result += UNICODE_CHARS.sample(rand(0..maxlength-i-1)).join
-  #  # if result == from/to ...
-  #end
-
   def deep_rand(*args)
     case args
     when Array
@@ -104,16 +58,45 @@ class ActiveSupport::TestCase
     end while true
   end
 
-  # Assumes: max >= step and step = 1e[-]N, both as strings
-  def random_number(max, step)
-    max.delete!('.')
-    precision = max.length
-    start = rand(precision) + 1
-    d = (rand(max.to_i) + 1) % 10**start
-    length = rand([0, 1..4, 4..precision].sample)
-    d = d.truncate(-start + length)
-    d = 10**(start - length) if d.zero?
-    BigDecimal(step) * d
+  # Return string representation of number selected randomly within given limits.
+  # Distrbiution is roughly uniform first with regard to: sign and exponent, then
+  # significand, with some extra skew towards most expected values and boundaries.
+  # Variants:
+  #   min max exp_range         range (magnitude)
+  #   -   +   MIN_EXP..min/max  0.5..min/max if min/max.exp
+  #   -   -   max..min          0.5..min if min.exp, max...1.0 if max.exp
+  #   -   0   MIN_EXP..min      0.5..min if min.exp
+  #   0   +   MIN_EXP..max      0.5..max if max.exp
+  #   +   +   min..max          0.5..max if max.exp, min...1.0 if min.exp
+  # TODO: alternate between floating-point and exponential representation.
+  def random_float(min: -Float::MAX_15, max: Float::MAX_15, except: [])
+    # For now assume ranges are same on both sides of 0.
+    assert_equal -min, max if min.negative? && max.positive?
+
+    include_zero = (min.negative? && max.positive?) || min.zero? || max.zero?
+    precision_range = [1..2, 3..4, 5..Float::DIG-1, Float::DIG]
+    # Returns 0.0 <=> (precision == 0).
+    precision_range << 0 if include_zero
+
+    min_frexp, max_frexp = [min, max].map(&:abs).minmax.map { |f| Math.frexp(f) }
+    fractions, exponents = min_frexp.zip(max_frexp)
+    exponents[0] = Float::MIN_EXP if include_zero
+    exp_range = Range.new(*exponents)
+    exp_range &= [Float::MIN_EXP..-10, -9..-4, -3..0, 1..4, 5..10, 11..Float::MAX_EXP]
+    begin
+      precision = deep_rand(*precision_range)
+      exp = deep_rand(*exp_range)
+
+      range = [0.5, 1.0, true]
+      range = [range[0], fractions[1], false] if exp == exponents[1]
+      range = [fractions[0], range[1], range[2]] if exp == exponents[0] && !include_zero
+
+      fr = rand(Range.new(*range))
+      number = Math.ldexp(fr, exp)
+      number *= [min.negative? ? -1.0 : 1.0, max.positive? ? 1.0 : -1.0].sample
+      number = number.limit(precision).clamp(min, max)
+    end while except.any? { |e| e === number }
+    number.to_s
   end
 
   def randomize_user_password!(user)
@@ -131,4 +114,9 @@ class ActiveSupport::TestCase
   def with_last_email
     yield(ActionMailer::Base.deliveries.last)
   end
+
+  def column_title(attribute)
+    model = self.class.name.delete_suffix('Test').singularize.constantize
+    model.human_attribute_name(attribute)
+  end
 end