Improve Comparable tests

test/t/comparable.rb

@@ -7,7 +7,7 @@ assert('Comparable#<', '15.3.3.2.1') do
     end
   end
 
-  (Foo.new < Foo.new) == false
+  assert_false(Foo.new < Foo.new)
 end
 
 assert('Comparable#<=', '15.3.3.2.2') do
@@ -18,7 +18,7 @@ assert('Comparable#<=', '15.3.3.2.2') do
     end
   end
 
-  (Foo.new <= Foo.new) == true
+  assert_true(Foo.new <= Foo.new)
 end
 
 assert('Comparable#==', '15.3.3.2.3') do
@@ -29,7 +29,7 @@ assert('Comparable#==', '15.3.3.2.3') do
     end
   end
 
-  (Foo.new == Foo.new) == true
+  assert_true(Foo.new == Foo.new)
 end
 
 assert('Comparable#>', '15.3.3.2.4') do
@@ -40,7 +40,7 @@ assert('Comparable#>', '15.3.3.2.4') do
     end
   end
 
-  (Foo.new > Foo.new) == false
+  assert_false(Foo.new > Foo.new)
 end
 
 assert('Comparable#>=', '15.3.3.2.5') do
@@ -51,7 +51,7 @@ assert('Comparable#>=', '15.3.3.2.5') do
     end
   end
 
-  (Foo.new >= Foo.new) == true
+  assert_true(Foo.new >= Foo.new)
 end
 
 assert('Comparable#between?', '15.3.3.2.6') do
@@ -63,9 +63,10 @@ assert('Comparable#between?', '15.3.3.2.6') do
   end
 
   c = Foo.new
-  c.between?(-1,  1) == false &&
-  c.between?(-1, -1) == false &&
-  c.between?( 1,  1) == false &&
-  c.between?( 1, -1) == true &&
-  c.between?(0, 0) == true
+
+  assert_false(c.between?(-1,  1))
+  assert_false(c.between?(-1, -1))
+  assert_false(c.between?( 1,  1))
+  assert_true(c.between?( 1, -1))
+  assert_true(c.between?(0, 0))
 end