Change sqlite3 boolean serialization to use 1 and 0

Abstract boolean serialization has been using 't' and 'f', with MySQL
overriding that to use 1 and 0.

This has the advantage that SQLite natively recognizes 1 and 0 as true
and false, but does not natively recognize 't' and 'f'.

This change in serialization requires a migration of stored boolean data
for SQLite databases, so it's implemented behind a configuration flag
whose default false value is deprecated. The flag itself can be
deprecated in a future version of Rails.  While loaded models will give
the correct result for boolean columns without migrating old data,
where() clauses will interact incorrectly with old data.

While working in this area, also change the abstract adapter to use
`"TRUE"` and `"FALSE"` as quoted values and `true` and `false` for
unquoted.  These are supported by PostreSQL, and MySQL remains
overriden.

2 files changed, 15 insertions, 2 deletions

diff --git a/activerecord/test/cases/adapters/postgresql/quoting_test.rb b/activerecord/test/cases/adapters/postgresql/quoting_test.rb
index a1e966b915..d7b23ad41d 100644
--- a/activerecord/test/cases/adapters/postgresql/quoting_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/quoting_test.rb
@@ -9,11 +9,11 @@ module ActiveRecord
         end
 
         def test_type_cast_true
-          assert_equal "t", @conn.type_cast(true)
+          assert_equal true, @conn.type_cast(true)
         end
 
         def test_type_cast_false
-          assert_equal "f", @conn.type_cast(false)
+          assert_equal false, @conn.type_cast(false)
         end
 
         def test_quote_float_nan
diff --git a/activerecord/test/cases/adapters/sqlite3/quoting_test.rb b/activerecord/test/cases/adapters/sqlite3/quoting_test.rb
index aefbb309e6..815453ad50 100644
--- a/activerecord/test/cases/adapters/sqlite3/quoting_test.rb
+++ b/activerecord/test/cases/adapters/sqlite3/quoting_test.rb
@@ -5,6 +5,11 @@ require "securerandom"
 class SQLite3QuotingTest < ActiveRecord::SQLite3TestCase
   def setup
     @conn = ActiveRecord::Base.connection
+    @initial_represent_boolean_as_integer = ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer
+  end
+
+  def teardown
+    ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer = @initial_represent_boolean_as_integer
   end
 
   def test_type_cast_binary_encoding_without_logger
@@ -15,11 +20,19 @@ class SQLite3QuotingTest < ActiveRecord::SQLite3TestCase
   end
 
   def test_type_cast_true
+    ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer = false
     assert_equal "t", @conn.type_cast(true)
+
+    ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer = true
+    assert_equal 1, @conn.type_cast(true)
   end
 
   def test_type_cast_false
+    ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer = false
     assert_equal "f", @conn.type_cast(false)
+
+    ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer = true
+    assert_equal 0, @conn.type_cast(false)
   end
 
   def test_type_cast_bigdecimal