WIP: all-your-base: add test generator (#510)

* Generate tests for "all your base"

* Move private row attribute to avoid ruby warning

This change is to remove a warning present in ruby versions
less than 2.3.0. A thread discussing this warning can be found
at https://bugs.ruby-lang.org/issues/10967. It is removed in
ruby/ruby@32a5a09.

* A bit more idiomatic Ruby

Also, the private call was ineffective.

Author: tommyschaefer

exercises/all-your-base/.meta/.version

@@ -0,0 +1 @@
+2

exercises/all-your-base/all_your_base_test.rb

@@ -1,9 +1,10 @@
-gem 'minitest', '>= 5.0.0'
 require 'minitest/autorun'
 require_relative 'all_your_base'
 
+# Test data version: aa12f2e
 class AllYourBaseTest < Minitest::Test
-  def test_single_bit_to_one_decimal
+  def test_single_bit_one_to_decimal
+    # skip
     digits = [1]
     input_base = 2
     output_base = 10
@@ -131,7 +132,7 @@ def test_empty_list
   def test_single_zero
     skip
     digits = [0]
-    input_base  = 10
+    input_base = 10
     output_base = 2
     expected = [0]
 
@@ -142,10 +143,10 @@ def test_single_zero
                  "Expected #{expected} but got #{converted}."
   end
 
-  def test_multiple_zeroes
+  def test_multiple_zeros
     skip
     digits = [0, 0, 0]
-    input_base  = 10
+    input_base = 10
     output_base = 2
     expected = [0]
 
@@ -175,129 +176,118 @@ def test_negative_digit
     digits = [1, -1, 1, 0, 1, 0]
     input_base = 2
     output_base = 10
-    expected = nil
-
-    converted = BaseConverter.convert(input_base, digits, output_base)
 
-    assert_equal expected, converted,
-                 "Input base: #{input_base}, output base #{output_base}. " \
-                 "Expected #{expected} but got #{converted}."
+    assert_raises ArgumentError do
+      BaseConverter.convert(input_base, digits, output_base)
+    end
   end
 
   def test_invalid_positive_digit
     skip
     digits = [1, 2, 1, 0, 1, 0]
     input_base = 2
     output_base = 10
-    expected = nil
-
-    converted = BaseConverter.convert(input_base, digits, output_base)
 
-    assert_equal expected, converted,
-                 "Input base: #{input_base}, output base #{output_base}. " \
-                 "Expected #{expected} but got #{converted}."
+    assert_raises ArgumentError do
+      BaseConverter.convert(input_base, digits, output_base)
+    end
   end
 
   def test_first_base_is_one
     skip
     digits = []
     input_base = 1
     output_base = 10
-    expected = nil
 
-    converted = BaseConverter.convert(input_base, digits, output_base)
-
-    assert_equal expected, converted,
-                 "Input base: #{input_base}, output base #{output_base}. " \
-                 "Expected #{expected} but got #{converted}."
+    assert_raises ArgumentError do
+      BaseConverter.convert(input_base, digits, output_base)
+    end
   end
 
   def test_second_base_is_one
     skip
     digits = [1, 0, 1, 0, 1, 0]
     input_base = 2
     output_base = 1
-    expected = nil
-
-    converted = BaseConverter.convert(input_base, digits, output_base)
 
-    assert_equal expected, converted,
-                 "Input base: #{input_base}, output base #{output_base}. " \
-                 "Expected #{expected} but got #{converted}."
+    assert_raises ArgumentError do
+      BaseConverter.convert(input_base, digits, output_base)
+    end
   end
 
   def test_first_base_is_zero
     skip
     digits = []
     input_base = 0
     output_base = 10
-    expected = nil
-
-    converted = BaseConverter.convert(input_base, digits, output_base)
 
-    assert_equal expected, converted,
-                 "Input base: #{input_base}, output base #{output_base}. " \
-                 "Expected #{expected} but got #{converted}."
+    assert_raises ArgumentError do
+      BaseConverter.convert(input_base, digits, output_base)
+    end
   end
 
   def test_second_base_is_zero
     skip
     digits = [7]
     input_base = 10
     output_base = 0
-    expected = nil
 
-    converted = BaseConverter.convert(input_base, digits, output_base)
-
-    assert_equal expected, converted,
-                 "Input base: #{input_base}, output base #{output_base}. " \
-                 "Expected #{expected} but got #{converted}."
+    assert_raises ArgumentError do
+      BaseConverter.convert(input_base, digits, output_base)
+    end
   end
 
   def test_first_base_is_negative
     skip
     digits = [1]
     input_base = -2
     output_base = 10
-    expected = nil
-
-    converted = BaseConverter.convert(input_base, digits, output_base)
 
-    assert_equal expected, converted,
-                 "Input base: #{input_base}, output base #{output_base}. " \
-                 "Expected #{expected} but got #{converted}."
+    assert_raises ArgumentError do
+      BaseConverter.convert(input_base, digits, output_base)
+    end
   end
 
   def test_second_base_is_negative
     skip
     digits = [1]
     input_base = 2
     output_base = -7
-    expected = nil
-
-    converted = BaseConverter.convert(input_base, digits, output_base)
 
-    assert_equal expected, converted,
-                 "Input base: #{input_base}, output base #{output_base}. " \
-                 "Expected #{expected} but got #{converted}."
+    assert_raises ArgumentError do
+      BaseConverter.convert(input_base, digits, output_base)
+    end
   end
 
   def test_both_bases_are_negative
     skip
     digits = [1]
     input_base = -2
     output_base = -7
-    expected = nil
 
-    converted = BaseConverter.convert(input_base, digits, output_base)
-
-    assert_equal expected, converted,
-                 "Input base: #{input_base}, output base #{output_base}. " \
-                 "Expected #{expected} but got #{converted}."
+    assert_raises ArgumentError do
+      BaseConverter.convert(input_base, digits, output_base)
+    end
   end
 
+  # Problems in exercism evolve over time, as we find better ways to ask
+  # questions.
+  # The version number refers to the version of the problem you solved,
+  # not your solution.
+  #
+  # Define a constant named VERSION inside of the top level BookKeeping
+  # module, which may be placed near the end of your file.
+  #
+  # In your file, it will look like this:
+  #
+  # module BookKeeping
+  #   VERSION = 1 # Where the version number matches the one in the test.
+  # end
+  #
+  # If you are curious, read more about constants on RubyDoc:
+  # http://ruby-doc.org/docs/ruby-doc-bundle/UsersGuide/rg/constants.html
   def test_bookkeeping
     skip
-    assert_equal 1, BookKeeping::VERSION
+    assert_equal 2, BookKeeping::VERSION
   end
 end

exercises/all-your-base/example.rb

@@ -1,31 +1,36 @@
 module BookKeeping
-  VERSION = 1
+  VERSION = 2
 end
 
 class BaseConverter
   def self.convert(base_from, number_array, base_to)
-    return if number_array.any?{|number| number < 0 || number >= base_from}
-    return if base_from <= 1 || base_to <= 1
+    fail ArgumentError if invalid_inputs?(base_from, number_array, base_to)
     return [] unless number_array.any?
     number_in_canonical_base = convert_to_canonical_base(number_array, base_from)
     convert_from_canonical_base(number_in_canonical_base, base_to)
   end
 
-  private
+  private_class_method
+
+  def self.invalid_inputs?(base_from, number_array, base_to)
+    number_array.any? { |number| number < 0 || number >= base_from } ||
+      base_from <= 1 || base_to <= 1
+  end
+
   def self.convert_to_canonical_base(number_array, base)
     total = 0
     number_array.reverse.each_with_index do |number, index|
-      total += number * base ** index
+      total += number * base**index
     end
     total
   end
 
   def self.convert_from_canonical_base(number, base_to)
     result = []
     current_number = number
-    while current_number >= base_to do
-     result << current_number % base_to
-     current_number = current_number / base_to
+    while current_number >= base_to
+      result << current_number % base_to
+      current_number /= base_to
     end
     result << current_number % base_to
     result.reverse

exercises/all-your-base/example.tt

@@ -0,0 +1,17 @@
+require 'minitest/autorun'
+require_relative 'all_your_base'
+
+# Test data version: <%= sha1 %>
+class AllYourBaseTest < Minitest::Test<% test_cases.each do |test_case| %>
+  def <%= test_case.test_name %>
+    <%= test_case.skipped %>
+<%= test_case.workload %>
+  end
+<% end %>
+
+<%= IO.read(XRUBY_LIB + '/bookkeeping.md') %>
+  def test_bookkeeping
+    skip
+    assert_equal <%= version.next %>, BookKeeping::VERSION
+  end
+end

lib/all_your_base_cases.rb

@@ -0,0 +1,109 @@
+class AllYourBaseCase < OpenStruct
+  def test_name
+    'test_%s' % description.downcase.tr(' -', '_')
+  end
+
+  def workload
+    indent(4, (assignments + assertion).join("\n")) + "\n"
+  end
+
+  def skipped
+    index.zero? ? '# skip' : 'skip'
+  end
+
+  private
+
+  def indent(size, text)
+    text.lines.each_with_object('') do |line, obj|
+      obj << (line == "\n" ? line : ' ' * size + line)
+    end
+  end
+
+  def assignments
+      [
+        "digits = #{input_digits}",
+        "input_base = #{input_base}",
+        "output_base = #{output_base}",
+      ]
+  end
+
+  def assertion
+    return error_assertion unless expected
+
+    [
+      "expected = #{expected}",
+      "",
+      "converted = BaseConverter.convert(input_base, digits, output_base)",
+      "",
+      "assert_equal expected, converted,",
+      indent(13, error_message),
+    ]
+  end
+
+  def error_assertion
+    [
+      "",
+      "assert_raises ArgumentError do",
+      "  BaseConverter.convert(input_base, digits, output_base)",
+      "end",
+    ]
+  end
+
+  def error_message
+    %q("Input base: #{input_base}, output base #{output_base}. " \\) \
+      "\n" + %q("Expected #{expected} but got #{converted}.")
+  end
+end
+
+class AllYourBaseCase::PreProcessor
+  class << self
+    attr_reader :row
+
+    def call(row)
+      @row = row
+
+      row.merge('expected' => expected_value)
+    end
+
+    private :row
+    private
+
+    def expected_value
+      return row['expected'] if row['expected']
+
+      if invalid_input_digits? || invalid_bases?
+        nil
+      elsif row['input_digits'].empty?
+        []
+      elsif input_of_zero?
+        [0]
+      else
+        handle_special_cases
+      end
+    end
+
+    def invalid_input_digits?
+      row['input_digits'].any? { |x| x < 0 || x >= row['input_base'] }
+    end
+
+    def invalid_bases?
+      row['input_base'] <= 1 || row['output_base'] <= 1
+    end
+
+    def input_of_zero?
+      row['input_digits'].all? { |x| x == 0 }
+    end
+
+    def handle_special_cases
+      [4,2] if row['input_digits'] == [0, 6, 0]
+    end
+  end
+end
+
+AllYourBaseCases = proc do |data|
+  JSON.parse(data)['cases'].map.with_index do |row, i|
+    AllYourBaseCase.new(
+      AllYourBaseCase::PreProcessor.call(row).merge(index: i),
+    )
+  end
+end