Add out of range tests of random number generator

Author: nobu

test/ruby/test_array.rb

@@ -3032,41 +3032,29 @@ def test_shuffle
     end
   end
 
-  def test_shuffle_random
-    gen = proc do
-      10000000
-    end
-    class << gen
-      alias rand call
-    end
+  def test_shuffle_random_out_of_range
+    gen = random_generator {10000000}
+    assert_raise(RangeError) {
+      [*0..2].shuffle(random: gen)
+    }
+    gen = random_generator {-1}
     assert_raise(RangeError) {
       [*0..2].shuffle(random: gen)
     }
   end
 
   def test_shuffle_random_clobbering
     ary = (0...10000).to_a
-    gen = proc do
+    gen = random_generator do
       ary.replace([])
       0.5
     end
-    class << gen
-      alias rand call
-    end
     assert_raise(RuntimeError) {ary.shuffle!(random: gen)}
   end
 
   def test_shuffle_random_zero
-    zero = Object.new
-    def zero.to_int
-      0
-    end
-    gen_to_int = proc do |max|
-      zero
-    end
-    class << gen_to_int
-      alias rand call
-    end
+    zero = Struct.new(:to_int).new(0)
+    gen_to_int = random_generator {|max| zero}
     ary = (0...10000).to_a
     assert_equal(ary.rotate, ary.shuffle(random: gen_to_int))
   end
@@ -3134,19 +3122,11 @@ def test_sample_unknown_keyword
   def test_sample_random_generator
     ary = (0...10000).to_a
     assert_raise(ArgumentError) {ary.sample(1, 2, random: nil)}
-    gen0 = proc do |max|
-      max/2
-    end
-    class << gen0
-      alias rand call
-    end
-    gen1 = proc do |max|
+    gen0 = random_generator {|max| max/2}
+    gen1 = random_generator do |max|
       ary.replace([])
       max/2
     end
-    class << gen1
-      alias rand call
-    end
     assert_equal(5000, ary.sample(random: gen0))
     assert_nil(ary.sample(random: gen1))
     assert_equal([], ary)
@@ -3177,20 +3157,23 @@ class << gen1
   end
 
   def test_sample_random_generator_half
-    half = Object.new
-    def half.to_int
-      5000
-    end
-    gen_to_int = proc do |max|
-      half
-    end
-    class << gen_to_int
-      alias rand call
-    end
+    half = Struct.new(:to_int).new(5000)
+    gen_to_int = random_generator {|max| half}
     ary = (0...10000).to_a
     assert_equal(5000, ary.sample(random: gen_to_int))
   end
 
+  def test_sample_random_out_of_range
+    gen = random_generator {10000000}
+    assert_raise(RangeError) {
+      [*0..2].sample(random: gen)
+    }
+    gen = random_generator {-1}
+    assert_raise(RangeError) {
+      [*0..2].sample(random: gen)
+    }
+  end
+
   def test_sample_random_invalid_generator
     ary = (0..10).to_a
     assert_raise(NoMethodError) {
@@ -3621,6 +3604,13 @@ def need_continuation
     end
     omit 'requires callcc support' unless respond_to?(:callcc, true)
   end
+
+  def random_generator(&block)
+    class << block
+      alias rand call
+    end
+    block
+  end
 end
 
 class TestArraySubclass < TestArray