1 files changed, 190 insertions, 0 deletions
diff --git a/activerecord/test/cases/adapters/postgresql/transaction_test.rb b/activerecord/test/cases/adapters/postgresql/transaction_test.rb
new file mode 100644
index 0000000000..8e952a9408
--- /dev/null
+++ b/activerecord/test/cases/adapters/postgresql/transaction_test.rb
@@ -0,0 +1,190 @@
+# frozen_string_literal: true
+
+require "cases/helper"
+require "support/connection_helper"
+require "concurrent/atomic/cyclic_barrier"
+
+module ActiveRecord
+  class PostgresqlTransactionTest < ActiveRecord::PostgreSQLTestCase
+    self.use_transactional_tests = false
+
+    class Sample < ActiveRecord::Base
+      self.table_name = "samples"
+    end
+
+    setup do
+      @abort, Thread.abort_on_exception = Thread.abort_on_exception, false
+      Thread.report_on_exception, @original_report_on_exception = false, Thread.report_on_exception if Thread.respond_to?(:report_on_exception)
+
+      @connection = ActiveRecord::Base.connection
+
+      @connection.transaction do
+        @connection.drop_table "samples", if_exists: true
+        @connection.create_table("samples") do |t|
+          t.integer "value"
+        end
+      end
+
+      Sample.reset_column_information
+    end
+
+    teardown do
+      @connection.drop_table "samples", if_exists: true
+
+      Thread.abort_on_exception = @abort
+      Thread.report_on_exception = @original_report_on_exception if Thread.respond_to?(:report_on_exception)
+    end
+
+    test "raises SerializationFailure when a serialization failure occurs" do
+      assert_raises(ActiveRecord::SerializationFailure) do
+        before = Concurrent::CyclicBarrier.new(2)
+        after = Concurrent::CyclicBarrier.new(2)
+
+        thread = Thread.new do
+          with_warning_suppression do
+            Sample.transaction isolation: :serializable do
+              before.wait
+              Sample.create value: Sample.sum(:value)
+              after.wait
+            end
+          end
+        end
+
+        begin
+          with_warning_suppression do
+            Sample.transaction isolation: :serializable do
+              before.wait
+              Sample.create value: Sample.sum(:value)
+              after.wait
+            end
+          end
+        ensure
+          thread.join
+        end
+      end
+    end
+
+    test "raises Deadlocked when a deadlock is encountered" do
+      with_warning_suppression do
+        assert_raises(ActiveRecord::Deadlocked) do
+          barrier = Concurrent::CyclicBarrier.new(2)
+
+          s1 = Sample.create value: 1
+          s2 = Sample.create value: 2
+
+          thread = Thread.new do
+            Sample.transaction do
+              s1.lock!
+              barrier.wait
+              s2.update value: 1
+            end
+          end
+
+          begin
+            Sample.transaction do
+              s2.lock!
+              barrier.wait
+              s1.update value: 2
+            end
+          ensure
+            thread.join
+          end
+        end
+      end
+    end
+
+    test "raises LockWaitTimeout when lock wait timeout exceeded" do
+      skip unless ActiveRecord::Base.connection.postgresql_version >= 90300
+      assert_raises(ActiveRecord::LockWaitTimeout) do
+        s = Sample.create!(value: 1)
+        latch1 = Concurrent::CountDownLatch.new
+        latch2 = Concurrent::CountDownLatch.new
+
+        thread = Thread.new do
+          Sample.transaction do
+            Sample.lock.find(s.id)
+            latch1.count_down
+            latch2.wait
+          end
+        end
+
+        begin
+          Sample.transaction do
+            latch1.wait
+            Sample.connection.execute("SET lock_timeout = 1")
+            Sample.lock.find(s.id)
+          end
+        ensure
+          Sample.connection.execute("SET lock_timeout = DEFAULT")
+          latch2.count_down
+          thread.join
+        end
+      end
+    end
+
+    test "raises QueryCanceled when statement timeout exceeded" do
+      assert_raises(ActiveRecord::QueryCanceled) do
+        s = Sample.create!(value: 1)
+        latch1 = Concurrent::CountDownLatch.new
+        latch2 = Concurrent::CountDownLatch.new
+
+        thread = Thread.new do
+          Sample.transaction do
+            Sample.lock.find(s.id)
+            latch1.count_down
+            latch2.wait
+          end
+        end
+
+        begin
+          Sample.transaction do
+            latch1.wait
+            Sample.connection.execute("SET statement_timeout = 1")
+            Sample.lock.find(s.id)
+          end
+        ensure
+          Sample.connection.execute("SET statement_timeout = DEFAULT")
+          latch2.count_down
+          thread.join
+        end
+      end
+    end
+
+    test "raises QueryCanceled when canceling statement due to user request" do
+      assert_raises(ActiveRecord::QueryCanceled) do
+        s = Sample.create!(value: 1)
+        latch = Concurrent::CountDownLatch.new
+
+        thread = Thread.new do
+          Sample.transaction do
+            Sample.lock.find(s.id)
+            latch.count_down
+            sleep(0.5)
+            conn = Sample.connection
+            pid = conn.query_value("SELECT pid FROM pg_stat_activity WHERE query LIKE '% FOR UPDATE'")
+            conn.execute("SELECT pg_cancel_backend(#{pid})")
+          end
+        end
+
+        begin
+          Sample.transaction do
+            latch.wait
+            Sample.lock.find(s.id)
+          end
+        ensure
+          thread.join
+        end
+      end
+    end
+
+    private
+
+      def with_warning_suppression
+        log_level = ActiveRecord::Base.connection.client_min_messages
+        ActiveRecord::Base.connection.client_min_messages = "error"
+        yield
+      ensure
+        ActiveRecord::Base.connection.client_min_messages = log_level
+      end
+  end
+end