add #first! and #last! to models & relations

Author: joshsusser

activerecord/lib/active_record/relation/finder_methods.rb

@@ -123,6 +123,11 @@ def first(*args)
       end
     end
 
+    # Same as #first! but raises RecordNotFound if no record is returned
+    def first!(*args)
+      self.first(*args) or raise RecordNotFound
+    end
+
     # A convenience wrapper for <tt>find(:last, *args)</tt>. You can pass in all the
     # same arguments to this method as you can to <tt>find(:last)</tt>.
     def last(*args)
@@ -137,6 +142,11 @@ def last(*args)
       end
     end
 
+    # Same as #last! but raises RecordNotFound if no record is returned
+    def last!(*args)
+      self.last(*args) or raise RecordNotFound
+    end
+
     # A convenience wrapper for <tt>find(:all, *args)</tt>. You can pass in all the
     # same arguments to this method as you can to <tt>find(:all)</tt>.
     def all(*args)

activerecord/test/cases/finder_test.rb

@@ -191,6 +191,30 @@ def test_first_failing
     assert_nil Topic.where("title = 'The Second Topic of the day!'").first
   end
 
+  def test_first_bang_present
+    assert_nothing_raised do
+      assert_equal topics(:second), Topic.where("title = 'The Second Topic of the day'").first!
+    end
+  end
+
+  def test_first_bang_missing
+    assert_raises ActiveRecord::RecordNotFound do
+      Topic.where("title = 'This title does not exist'").first!
+    end
+  end
+
+  def test_last_bang_present
+    assert_nothing_raised do
+      assert_equal topics(:second), Topic.where("title = 'The Second Topic of the day'").last!
+    end
+  end
+
+  def test_last_bang_missing
+    assert_raises ActiveRecord::RecordNotFound do
+      Topic.where("title = 'This title does not exist'").last!
+    end
+  end
+
   def test_unexisting_record_exception_handling
     assert_raise(ActiveRecord::RecordNotFound) {
       Topic.find(1).parent