updates String#to_(date|date_time|time) to return nil for blank strings

activesupport/lib/active_support/core_ext/string/conversions.rb

@@ -30,16 +30,19 @@ def ord
 
   # Form can be either :utc (default) or :local.
   def to_time(form = :utc)
+    return nil if self.blank?
     d = ::Date._parse(self, false).values_at(:year, :mon, :mday, :hour, :min, :sec, :sec_fraction).map { |arg| arg || 0 }
     d[6] *= 1000000
     ::Time.send("#{form}_time", *d)
   end
 
   def to_date
+    return nil if self.blank?
     ::Date.new(*::Date._parse(self, false).values_at(:year, :mon, :mday))
   end
 
   def to_datetime
+    return nil if self.blank?
     d = ::Date._parse(self, false).values_at(:year, :mon, :mday, :hour, :min, :sec, :zone, :sec_fraction).map { |arg| arg || 0 }
     d[5] += d.pop
     ::DateTime.civil(*d)

activesupport/test/core_ext/string_ext_test.rb

@@ -117,17 +117,20 @@ def test_string_to_time
     assert_equal Time.local(2005, 2, 27, 23, 50, 19, 275038), "2005-02-27T23:50:19.275038".to_time(:local)
     assert_equal DateTime.civil(2039, 2, 27, 23, 50), "2039-02-27 23:50".to_time
     assert_equal Time.local_time(2039, 2, 27, 23, 50), "2039-02-27 23:50".to_time(:local)
+    assert_equal nil, "".to_time
   end
-  
+
   def test_string_to_datetime
     assert_equal DateTime.civil(2039, 2, 27, 23, 50), "2039-02-27 23:50".to_datetime
     assert_equal 0, "2039-02-27 23:50".to_datetime.offset # use UTC offset
     assert_equal ::Date::ITALY, "2039-02-27 23:50".to_datetime.start # use Ruby's default start value
     assert_equal DateTime.civil(2039, 2, 27, 23, 50, 19 + Rational(275038, 1000000), "-04:00"), "2039-02-27T23:50:19.275038-04:00".to_datetime
+    assert_equal nil, "".to_datetime
   end
-  
+
   def test_string_to_date
     assert_equal Date.new(2005, 2, 27), "2005-02-27".to_date
+    assert_equal nil, "".to_date
   end
 
   def test_access
@@ -255,7 +258,7 @@ def test_mb_chars_returns_string
   string.rb - Interpolation for String.
 
   Copyright (C) 2005-2009 Masao Mutoh
- 
+
   You may redistribute it and/or modify it under the same
   license terms as Ruby.
 =end