Prefer ActiveRecord.default_timezone over per-class accessor (rsim#234)

Calling `ar_class.default_timezone` on Rails 7.0.x prints

  DEPRECATION WARNING: ActiveRecord::Base.default_timezone is
  deprecated and will be removed in Rails 7.1. Use
  ActiveRecord.default_timezone instead.

even though both accessors return the same value. The per-class
accessor was introduced as a deprecated proxy in Rails 7.0
(rails/rails@c3f43075a3) and removed entirely in Rails 7.1
(rails/rails@96c9db1b48), so the warning only fires on Rails 7.0.x.

Switch the order in PLSQL::Schema#default_timezone so that we ask the
module-level ActiveRecord.default_timezone first when it is available
(AR 7.0+) and only fall back to the per-class accessor on pre-7.0 AR
where the module-level one does not exist. This silences the warning
on Rails 7.0.x and is a no-op on Rails 7.1+ (where the per-class
accessor was already gone) and on Rails <= 6.x (where the module-level
accessor did not yet exist).

Add a regression test that captures deprecator output while resolving
plsql.default_timezone with `activerecord_class` set, and asserts that
no warning mentioning default_timezone was raised. The existing
ActiveRecord.default_timezone is captured before assignment and
restored from the ensure block alongside the deprecator behavior so
the test is order-independent.

Verified by rsim#269 / rsim#271 that the test fails on AR 7.0 without this fix
and passes on AR 7.1+ regardless.

Fixes rsim#234

References:
- rails/rails@c3f43075a3 (added the deprecated delegators in Rails 7.0)
- rails/rails@96c9db1b48 (removed them in Rails 7.1)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: yahonda

lib/plsql/schema.rb

@@ -99,12 +99,15 @@ def default_timezone
         @original_schema.default_timezone
       else
         @default_timezone ||
-          # Use ActiveRecord default_timezone when ActiveRecord connection is used,
-          # preferring the connection's activerecord_class so a subclass override
-          # (available in AR < 8.0) is honored before falling back to the
-          # module-level accessor (AR 7.0+; the only one in AR 8.0+).
-          (@connection && (ar_class = @connection.activerecord_class) &&
-            (ar_class.respond_to?(:default_timezone) ? ar_class.default_timezone : ActiveRecord.default_timezone)) ||
+          # Use ActiveRecord default_timezone when ActiveRecord connection is used.
+          # Prefer the module-level accessor (AR 7.0+; the only one in AR 8.0+) so
+          # that AR 7.0/7.1's deprecation warning for ActiveRecord::Base.default_timezone
+          # is not emitted. Fall back to the per-class accessor only on pre-7.0 AR,
+          # where ActiveRecord.default_timezone does not exist.
+          (@connection && @connection.activerecord_class &&
+            (ActiveRecord.respond_to?(:default_timezone) ?
+              ActiveRecord.default_timezone :
+              @connection.activerecord_class.default_timezone)) ||
           # default to local timezone
           :local
       end

spec/plsql/schema_spec.rb

@@ -218,6 +218,26 @@ class TestModel < TestBaseModel
     expect(plsql.default_timezone).to eq(:utc)
   end
 
+  it "should not emit ActiveRecord::Base.default_timezone deprecation warning (#234)" do
+    skip "ActiveRecord.default_timezone is not available" unless ActiveRecord.respond_to?(:default_timezone=)
+
+    original_default_timezone = ActiveRecord.default_timezone
+    ActiveRecord.default_timezone = :utc
+
+    deprecator = ActiveRecord.respond_to?(:deprecator) ? ActiveRecord.deprecator : ActiveSupport::Deprecation
+    original_behavior = deprecator.behavior
+    warnings = []
+    begin
+      deprecator.behavior = ->(message, *) { warnings << message }
+      expect(plsql.default_timezone).to eq(:utc)
+    ensure
+      deprecator.behavior = original_behavior
+      ActiveRecord.default_timezone = original_default_timezone
+    end
+
+    expect(warnings.grep(/default_timezone/)).to be_empty
+  end
+
   it "should have the same connection as default schema" do
     expect(plsql.hr.connection).to eq(plsql.connection)
   end