Move integer range validation to never raise on assignment

Given that this was originally added to normalize an error that would
have otherwise come from the database (inconsistently), it's more
natural for us to raise in `type_cast_for_database`, rather than
`type_cast_from_user`. This way, things like numericality validators can
handle it instead if the user chooses to do so. It also fixes an issue
where assigning an out of range value would make it impossible to assign
a new value later.

This fixes several vague issues, none of which were ever directly
reported, so I have no issue number to give. Places it was mentioned
which I can remember:

- https://github.com/thoughtbot/shoulda-matchers/blob/9ba21381d7caf045053a81f32df7de2f49687820/lib/shoulda/matchers/active_model/allow_value_matcher.rb#L261-L263
- https://github.com/rails/rails/issues/18653#issuecomment-71197026

4 files changed, 45 insertions, 20 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 2054c9573e..22b1c8e95b 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,11 @@
+*   Integer types will no longer raise a `RangeError` when assigning an
+    attribute, but will instead raise when going to the database.
+
+    Fixes several vague issues which were never reported directly. See the
+    commit message from the commit which added this line for some examples.
+
+    *Sean Griffin*
+
 *   Values which would error while being sent to the database (such as an
     ASCII-8BIT string with invalid UTF-8 bytes on Sqlite3), no longer error on
     assignment. They will still error when sent to the database, but you are
diff --git a/activerecord/lib/active_record/type/integer.rb b/activerecord/lib/active_record/type/integer.rb
index 394fe008f9..90ca9f88da 100644
--- a/activerecord/lib/active_record/type/integer.rb
+++ b/activerecord/lib/active_record/type/integer.rb
@@ -16,13 +16,19 @@ module ActiveRecord
         :integer
       end
 
-      alias type_cast_for_database type_cast
-
       def type_cast_from_database(value)
         return if value.nil?
         value.to_i
       end
 
+      def type_cast_for_database(value)
+        result = type_cast(value)
+        if result
+          ensure_in_range(result)
+        end
+        result
+      end
+
       protected
 
       attr_reader :range
@@ -34,9 +40,7 @@ module ActiveRecord
         when true then 1
         when false then 0
         else
-          result = value.to_i rescue nil
-          ensure_in_range(result) if result
-          result
+          value.to_i rescue nil
         end
       end
 
diff --git a/activerecord/test/cases/type/integer_test.rb b/activerecord/test/cases/type/integer_test.rb
index ff956b7680..0c60f0690c 100644
--- a/activerecord/test/cases/type/integer_test.rb
+++ b/activerecord/test/cases/type/integer_test.rb
@@ -60,55 +60,68 @@ module ActiveRecord
 
       test "values below int min value are out of range" do
         assert_raises(::RangeError) do
-          Integer.new.type_cast_from_user("-2147483649")
+          Integer.new.type_cast_for_database(-2147483649)
         end
       end
 
       test "values above int max value are out of range" do
         assert_raises(::RangeError) do
-          Integer.new.type_cast_from_user("2147483648")
+          Integer.new.type_cast_for_database(2147483648)
         end
       end
 
       test "very small numbers are out of range" do
         assert_raises(::RangeError) do
-          Integer.new.type_cast_from_user("-9999999999999999999999999999999")
+          Integer.new.type_cast_for_database(-9999999999999999999999999999999)
         end
       end
 
       test "very large numbers are out of range" do
         assert_raises(::RangeError) do
-          Integer.new.type_cast_from_user("9999999999999999999999999999999")
+          Integer.new.type_cast_for_database(9999999999999999999999999999999)
         end
       end
 
       test "normal numbers are in range" do
         type = Integer.new
-        assert_equal(0, type.type_cast_from_user("0"))
-        assert_equal(-1, type.type_cast_from_user("-1"))
-        assert_equal(1, type.type_cast_from_user("1"))
+        assert_equal(0, type.type_cast_for_database(0))
+        assert_equal(-1, type.type_cast_for_database(-1))
+        assert_equal(1, type.type_cast_for_database(1))
       end
 
       test "int max value is in range" do
-        assert_equal(2147483647, Integer.new.type_cast_from_user("2147483647"))
+        assert_equal(2147483647, Integer.new.type_cast_for_database(2147483647))
       end
 
       test "int min value is in range" do
-        assert_equal(-2147483648, Integer.new.type_cast_from_user("-2147483648"))
+        assert_equal(-2147483648, Integer.new.type_cast_for_database(-2147483648))
       end
 
       test "columns with a larger limit have larger ranges" do
         type = Integer.new(limit: 8)
 
-        assert_equal(9223372036854775807, type.type_cast_from_user("9223372036854775807"))
-        assert_equal(-9223372036854775808, type.type_cast_from_user("-9223372036854775808"))
+        assert_equal(9223372036854775807, type.type_cast_for_database(9223372036854775807))
+        assert_equal(-9223372036854775808, type.type_cast_for_database(-9223372036854775808))
         assert_raises(::RangeError) do
-          type.type_cast_from_user("-9999999999999999999999999999999")
+          type.type_cast_for_database(-9999999999999999999999999999999)
         end
         assert_raises(::RangeError) do
-          type.type_cast_from_user("9999999999999999999999999999999")
+          type.type_cast_for_database(9999999999999999999999999999999)
         end
       end
+
+      test "values which are out of range can be re-assigned" do
+        klass = Class.new(ActiveRecord::Base) do
+          self.table_name = 'posts'
+          attribute :foo, Type::Integer.new
+        end
+        model = klass.new
+
+        model.foo = 2147483648
+        model.foo = 1
+
+        assert_equal 1, model.foo
+      end
     end
   end
 end
diff --git a/activerecord/test/cases/type/unsigned_integer_test.rb b/activerecord/test/cases/type/unsigned_integer_test.rb
index b6f673109e..4b8e2fb518 100644
--- a/activerecord/test/cases/type/unsigned_integer_test.rb
+++ b/activerecord/test/cases/type/unsigned_integer_test.rb
@@ -4,12 +4,12 @@ module ActiveRecord
   module Type
     class UnsignedIntegerTest < ActiveRecord::TestCase
       test "unsigned int max value is in range" do
-        assert_equal(4294967295, UnsignedInteger.new.type_cast_from_user("4294967295"))
+        assert_equal(4294967295, UnsignedInteger.new.type_cast_for_database(4294967295))
       end
 
       test "minus value is out of range" do
         assert_raises(::RangeError) do
-          UnsignedInteger.new.type_cast_from_user("-1")
+          UnsignedInteger.new.type_cast_for_database(-1)
         end
       end
     end