add assert_between to the gem

README.rdoc

@@ -1,7 +1,3 @@
-
-
-
-
 = assertions
 * Project Page: http://rubyforge.org/projects/assertions/
 
@@ -24,6 +20,8 @@ including:
 * Assertions that verify enumerables are sorted
   (Test::Unit::Assertions#assert_sorted, Test::Unit::Assertions#assert_sorted_desc,
   Test::Unit::Assertions#assert_sorted_by, Test::Unit::Assertions#assert_sorted_by_desc)
+* An assertion that verifies x1 < y < x2
+  (Test::Unit::Assertion#assert_between)
 
 == PROBLEMS:
 None (known).
@@ -92,6 +90,11 @@ None (known).
      # Verify an enumerable is sorted descending based on a key
      #
      assert_sorted_by(:key, [{:key => 2}, {:key => 1}])
+
+    #
+    # Verify a thing is between two other things
+    #
+    assert_between(1, 3, 2)
    end
  end
 

README.txt

@@ -0,0 +1 @@
+./README.rdoc

assertions.gemspec

@@ -1,6 +1,6 @@
 spec = Gem::Specification.new do |s|
   s.name = 'assertions'
-  s.version = '1.5.0'
+  s.version = '1.6.0'
   s.summary = "More Assertions for Test::Unit::Assertions"
   s.description = %{This project adds some additional assertions to Test::Unit::Assertions, including assert_raise_message (allowing verification of error messages) and assert_greater_than.}
   s.files = Dir['lib/**/*.rb'] + Dir['test/**/*.rb'] + Dir['examples/**/*.rb']

examples/example.rb

@@ -44,12 +44,12 @@ def test_assertions
     #
     # Verify an enumerable is sorted
     #
-    assert_sorted([1,2,3])
+    assert_sorted([1, 2, 3])
 
     #
     # Verify an enumerable is sorted descending
     #
-    assert_sorted_desc([3,2,1])
+    assert_sorted_desc([3, 2, 1])
 
     #
     # Verify an enumerable is sorted based on a key
@@ -60,5 +60,10 @@ def test_assertions
     # Verify an enumerable is sorted descending based on a key
     #
     assert_sorted_by(:key, [{:key => 2}, {:key => 1}])
+
+    #
+    # Verify a thing is between two other things
+    #
+    assert_between(1, 3, 2)
   end
 end

lib/assertions.rb

@@ -202,6 +202,37 @@ def assert_sorted_by_desc(key, enum, message = "")
     check_enum_for_key_sortability(key, enum)
     assert_sorted_desc enum.map{ |x| x.is_a?(Hash) ? x[key] : x.send(key) }
   end
+
+  #
+  # ====Description:
+  # Find out if a something is between two other things when compared.
+  # It asserts that lhs1 < rhs < lhs2 or lhs1 > rhs > lhs2
+  #
+  # ====Example:
+  #  assert_between(Date.yesterday, Date.tomorrow, Date.today)
+  #
+  # ====Parameters:
+  # [lhs1]
+  #      One of the things to compare against
+  # [lhs2]
+  #      The other thing to compare against
+  # [rhs]
+  #      The thing being tested for between-ness
+  # [message = ""]
+  #      An optional additional message that will be displayed if the
+  #      assertion fails.
+  #
+  def assert_between(lhs1, lhs2, rhs, message="")
+    if lhs1 == lhs2
+      full_message = build_message(message, "Gave the same value for both sides of range. <?> was not equal to <?>", rhs, lhs1)
+      assert_block(full_message) { lhs1 == rhs }
+    else
+      lower  = lhs1 < lhs2 ? lhs1 : lhs2
+      higher = lhs1 < lhs2 ? lhs2 : lhs1
+      full_message = build_message(message, "<?> was not between <?> and <?>", rhs, lower, higher)
+      assert_block(full_message) { lower < rhs && rhs < higher }
+    end
+  end
 
   #
   # ====Description:

test/test_assertions.rb

@@ -218,6 +218,32 @@ def test_assert_sorted_by_desc
     end
   end
 
+  def test_assert_between
+    assert_raise_message("Gave the same value for both sides of range. <5> was not equal to <4>", Test::Unit::AssertionFailedError) do
+      assert_between 4, 4, 5
+    end
+
+    assert_raise_message("<5> was not between <2> and <3>", Test::Unit::AssertionFailedError) do
+      assert_between 3, 2, 5
+    end
+
+    assert_between 4, 8, 6
+    assert_between 8, 4, 6
+    assert_fail do
+      assert_between 4, 6, 8
+    end
+
+    today     = DateTime.now
+    yesterday = today - 1
+    tomorrow  = today + 1
+    assert_between yesterday, tomorrow,  today
+    assert_between tomorrow,  yesterday, today
+
+    assert_fail do
+      assert_between tomorrow, today, yesterday
+    end
+  end
+
   def test_assert_raise_message
     #
     # Verify that the assertion passes correctly.