Tested Array#bsearch more thoroughly

mrbgems/mruby-array-ext/test/array.rb

@@ -228,18 +228,38 @@ end
 
 assert("Array#bsearch") do
   # Find minimum mode
-  a = [0, 4, 7, 10, 12]
-  assert_include [4, 7], a.bsearch {|x| x >= 4 }
-  assert_equal 7, a.bsearch {|x| x >= 6 }
-  assert_equal 0, a.bsearch {|x| x >= -1 }
-  assert_nil a.bsearch {|x| x >= 100 }
+  a = [0, 2, 4]
+  assert_equal 0, a.bsearch{ |x| x >= -1 }
+  assert_equal 0, a.bsearch{ |x| x >= 0 }
+  assert_equal 2, a.bsearch{ |x| x >= 1 }
+  assert_equal 2, a.bsearch{ |x| x >= 2 }
+  assert_equal 4, a.bsearch{ |x| x >= 3 }
+  assert_equal 4, a.bsearch{ |x| x >= 4 }
+  assert_nil      a.bsearch{ |x| x >= 5 }
 
   # Find any mode
-  a = [0, 4, 7, 10, 12]
-  assert_include [4, 7], a.bsearch {|x| 1 - (x / 4).truncate }
-  assert_nil a.bsearch {|x| 4 - (x / 2).truncate }
-  assert_equal(nil, a.bsearch {|x| 1 })
-  assert_equal(nil, a.bsearch {|x| -1 })
+  a = [0, 4, 8]
+  def between(lo, x, hi)
+    if x < lo
+      1
+    elsif x > hi
+      -1
+    else
+      0
+    end
+  end
+  assert_nil      a.bsearch{ |x| between(-3, x, -1) }
+  assert_equal 0, a.bsearch{ |x| between(-1, x,  1) }
+  assert_nil      a.bsearch{ |x| between( 1, x,  3) }
+  assert_equal 4, a.bsearch{ |x| between( 3, x,  5) }
+  assert_nil      a.bsearch{ |x| between( 5, x,  7) }
+  assert_equal 8, a.bsearch{ |x| between( 7, x,  9) }
+  assert_nil      a.bsearch{ |x| between( 9, x, 11) }
+
+  assert_equal 0, a.bsearch{ |x| between( 0, x,  3) }
+  assert_equal 4, a.bsearch{ |x| between( 0, x,  4) }
+  assert_equal 4, a.bsearch{ |x| between( 4, x,  8) }
+  assert_equal 8, a.bsearch{ |x| between( 5, x,  8) }
 end
 
 assert("Array#delete_if") do