Enable `Style/RedundantBegin` cop to avoid newly adding redundant begin block

Currently we sometimes find a redundant begin block in code review
(e.g. https://github.com/rails/rails/pull/33604#discussion_r209784205).

I'd like to enable `Style/RedundantBegin` cop to avoid that, since
rescue/else/ensure are allowed inside do/end blocks in Ruby 2.5
(https://bugs.ruby-lang.org/issues/12906), so we'd probably meets with
that situation than before.

4 files changed, 37 insertions, 49 deletions

diff --git a/activerecord/test/cases/adapters/mysql2/active_schema_test.rb b/activerecord/test/cases/adapters/mysql2/active_schema_test.rb
index 261fee13eb..0d5b43afe5 100644
--- a/activerecord/test/cases/adapters/mysql2/active_schema_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/active_schema_test.rb
@@ -130,29 +130,25 @@ class Mysql2ActiveSchemaTest < ActiveRecord::Mysql2TestCase
 
   def test_add_timestamps
     with_real_execute do
-      begin
-        ActiveRecord::Base.connection.create_table :delete_me
-        ActiveRecord::Base.connection.add_timestamps :delete_me, null: true
-        assert column_present?("delete_me", "updated_at", "datetime")
-        assert column_present?("delete_me", "created_at", "datetime")
-      ensure
-        ActiveRecord::Base.connection.drop_table :delete_me rescue nil
-      end
+      ActiveRecord::Base.connection.create_table :delete_me
+      ActiveRecord::Base.connection.add_timestamps :delete_me, null: true
+      assert column_present?("delete_me", "updated_at", "datetime")
+      assert column_present?("delete_me", "created_at", "datetime")
+    ensure
+      ActiveRecord::Base.connection.drop_table :delete_me rescue nil
     end
   end
 
   def test_remove_timestamps
     with_real_execute do
-      begin
-        ActiveRecord::Base.connection.create_table :delete_me do |t|
-          t.timestamps null: true
-        end
-        ActiveRecord::Base.connection.remove_timestamps :delete_me, null: true
-        assert_not column_present?("delete_me", "updated_at", "datetime")
-        assert_not column_present?("delete_me", "created_at", "datetime")
-      ensure
-        ActiveRecord::Base.connection.drop_table :delete_me rescue nil
+      ActiveRecord::Base.connection.create_table :delete_me do |t|
+        t.timestamps null: true
       end
+      ActiveRecord::Base.connection.remove_timestamps :delete_me, null: true
+      assert_not column_present?("delete_me", "updated_at", "datetime")
+      assert_not column_present?("delete_me", "created_at", "datetime")
+    ensure
+      ActiveRecord::Base.connection.drop_table :delete_me rescue nil
     end
   end
 
diff --git a/activerecord/test/cases/adapters/postgresql/infinity_test.rb b/activerecord/test/cases/adapters/postgresql/infinity_test.rb
index 5e56ce8427..b1bf06d9e9 100644
--- a/activerecord/test/cases/adapters/postgresql/infinity_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/infinity_test.rb
@@ -71,17 +71,15 @@ class PostgresqlInfinityTest < ActiveRecord::PostgreSQLTestCase
   end
 
   test "assigning 'infinity' on a datetime column with TZ aware attributes" do
-    begin
-      in_time_zone "Pacific Time (US & Canada)" do
-        record = PostgresqlInfinity.create!(datetime: "infinity")
-        assert_equal Float::INFINITY, record.datetime
-        assert_equal record.datetime, record.reload.datetime
-      end
-    ensure
-      # setting time_zone_aware_attributes causes the types to change.
-      # There is no way to do this automatically since it can be set on a superclass
-      PostgresqlInfinity.reset_column_information
+    in_time_zone "Pacific Time (US & Canada)" do
+      record = PostgresqlInfinity.create!(datetime: "infinity")
+      assert_equal Float::INFINITY, record.datetime
+      assert_equal record.datetime, record.reload.datetime
     end
+  ensure
+    # setting time_zone_aware_attributes causes the types to change.
+    # There is no way to do this automatically since it can be set on a superclass
+    PostgresqlInfinity.reset_column_information
   end
 
   test "where clause with infinite range on a datetime column" do
diff --git a/activerecord/test/cases/adapters/postgresql/schema_test.rb b/activerecord/test/cases/adapters/postgresql/schema_test.rb
index 931a9bd0be..336cec30ca 100644
--- a/activerecord/test/cases/adapters/postgresql/schema_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/schema_test.rb
@@ -108,23 +108,19 @@ class SchemaTest < ActiveRecord::PostgreSQLTestCase
   end
 
   def test_create_schema
-    begin
-      @connection.create_schema "test_schema3"
-      assert @connection.schema_names.include? "test_schema3"
-    ensure
-      @connection.drop_schema "test_schema3"
-    end
+    @connection.create_schema "test_schema3"
+    assert @connection.schema_names.include? "test_schema3"
+  ensure
+    @connection.drop_schema "test_schema3"
   end
 
   def test_raise_create_schema_with_existing_schema
-    begin
+    @connection.create_schema "test_schema3"
+    assert_raises(ActiveRecord::StatementInvalid) do
       @connection.create_schema "test_schema3"
-      assert_raises(ActiveRecord::StatementInvalid) do
-        @connection.create_schema "test_schema3"
-      end
-    ensure
-      @connection.drop_schema "test_schema3"
     end
+  ensure
+    @connection.drop_schema "test_schema3"
   end
 
   def test_drop_schema
diff --git a/activerecord/test/cases/adapters/sqlite3/sqlite3_create_folder_test.rb b/activerecord/test/cases/adapters/sqlite3/sqlite3_create_folder_test.rb
index d70486605f..cfc9853aba 100644
--- a/activerecord/test/cases/adapters/sqlite3/sqlite3_create_folder_test.rb
+++ b/activerecord/test/cases/adapters/sqlite3/sqlite3_create_folder_test.rb
@@ -8,17 +8,15 @@ module ActiveRecord
     class SQLite3CreateFolder < ActiveRecord::SQLite3TestCase
       def test_sqlite_creates_directory
         Dir.mktmpdir do |dir|
-          begin
-            dir = Pathname.new(dir)
-            @conn = Base.sqlite3_connection database: dir.join("db/foo.sqlite3"),
-                                 adapter: "sqlite3",
-                                 timeout: 100
+          dir = Pathname.new(dir)
+          @conn = Base.sqlite3_connection database: dir.join("db/foo.sqlite3"),
+                               adapter: "sqlite3",
+                               timeout: 100
 
-            assert Dir.exist? dir.join("db")
-            assert File.exist? dir.join("db/foo.sqlite3")
-          ensure
-            @conn.disconnect! if @conn
-          end
+          assert Dir.exist? dir.join("db")
+          assert File.exist? dir.join("db/foo.sqlite3")
+        ensure
+          @conn.disconnect! if @conn
         end
       end
     end