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# frozen_string_literal: true
require "cases/helper"
require "models/person"
require "action_dispatch"
module ActiveRecord
class DatabaseSelectorTest < ActiveRecord::TestCase
setup do
@session_store = {}
@session = ActiveRecord::Middleware::DatabaseSelector::Resolver::Session.new(@session_store)
end
teardown do
clean_up_connection_handler
end
def test_empty_session
assert_equal Time.at(0), @session.last_write_timestamp
end
def test_writing_the_session_timestamps
assert @session.update_last_write_timestamp
session2 = ActiveRecord::Middleware::DatabaseSelector::Resolver::Session.new(@session_store)
assert_equal @session.last_write_timestamp, session2.last_write_timestamp
end
def test_writing_session_time_changes
assert @session.update_last_write_timestamp
before = @session.last_write_timestamp
sleep(0.1)
assert @session.update_last_write_timestamp
assert_not_equal before, @session.last_write_timestamp
end
def test_read_from_replicas
@session_store[:last_write] = ActiveRecord::Middleware::DatabaseSelector::Resolver::Session.convert_time_to_timestamp(Time.now - 5.seconds)
resolver = ActiveRecord::Middleware::DatabaseSelector::Resolver.new(@session)
called = false
resolver.read do
called = true
assert ActiveRecord::Base.connected_to?(role: :reading)
end
assert called
end
unless in_memory_db?
def test_can_write_while_reading_from_replicas_if_explicit
@session_store[:last_write] = ActiveRecord::Middleware::DatabaseSelector::Resolver::Session.convert_time_to_timestamp(Time.now - 5.seconds)
resolver = ActiveRecord::Middleware::DatabaseSelector::Resolver.new(@session)
called = false
resolver.read do
ActiveRecord::Base.establish_connection :arunit
called = true
assert ActiveRecord::Base.connected_to?(role: :reading)
assert_predicate ActiveRecord::Base.lease_connection, :preventing_writes?
ActiveRecord::Base.connected_to(role: :writing, prevent_writes: false) do
assert ActiveRecord::Base.connected_to?(role: :writing)
assert_not_predicate ActiveRecord::Base.lease_connection, :preventing_writes?
end
assert ActiveRecord::Base.connected_to?(role: :reading)
assert_predicate ActiveRecord::Base.lease_connection, :preventing_writes?
end
assert called
end
end
def test_read_from_primary
@session_store[:last_write] = ActiveRecord::Middleware::DatabaseSelector::Resolver::Session.convert_time_to_timestamp(Time.now)
resolver = ActiveRecord::Middleware::DatabaseSelector::Resolver.new(@session)
called = false
resolver.read do
called = true
assert ActiveRecord::Base.connected_to?(role: :writing)
end
assert called
end
def test_write_to_primary
resolver = ActiveRecord::Middleware::DatabaseSelector::Resolver.new(@session)
# Session should start empty
assert_nil @session_store[:last_write]
called = false
resolver.write do
assert ActiveRecord::Base.connected_to?(role: :writing)
called = true
end
assert called
# and be populated by the last write time
assert @session_store[:last_write]
end
def test_write_to_primary_and_update_custom_context
custom_context = Class.new(ActiveRecord::Middleware::DatabaseSelector::Resolver::Session) do
def update_last_write_timestamp
super
@wrote_to_primary = true
end
def save(response)
response[:wrote_to_primary] = @wrote_to_primary
end
end
resolver = ActiveRecord::Middleware::DatabaseSelector::Resolver.new(custom_context.new(@session_store))
# Session should start empty
assert_nil @session_store[:last_write]
called = false
resolver.write do
assert ActiveRecord::Base.connected_to?(role: :writing)
called = true
end
assert called
response = {}
resolver.update_context(response)
# and be populated by the last write time
assert @session_store[:last_write]
# plus the response updated
assert response[:wrote_to_primary]
end
def test_write_to_primary_with_exception
resolver = ActiveRecord::Middleware::DatabaseSelector::Resolver.new(@session)
# Session should start empty
assert_nil @session_store[:last_write]
called = false
assert_raises(ActiveRecord::RecordNotFound) do
resolver.write do
assert ActiveRecord::Base.connected_to?(role: :writing)
called = true
raise ActiveRecord::RecordNotFound
end
end
assert called
# and be populated by the last write time
assert @session_store[:last_write]
end
def test_read_from_primary_with_options
resolver = ActiveRecord::Middleware::DatabaseSelector::Resolver.new(@session, delay: 5.seconds)
# Session should start empty
assert_nil @session_store[:last_write]
called = false
resolver.write do
assert ActiveRecord::Base.connected_to?(role: :writing)
called = true
end
assert called
# and be populated by the last write time
assert @session_store[:last_write]
read = false
resolver.read do
assert ActiveRecord::Base.connected_to?(role: :writing)
read = true
end
assert read
end
def test_preventing_writes_turns_off_for_primary_write
resolver = ActiveRecord::Middleware::DatabaseSelector::Resolver.new(@session, delay: 5.seconds)
# Session should start empty
assert_nil @session_store[:last_write]
called = false
resolver.write do
assert ActiveRecord::Base.connected_to?(role: :writing)
called = true
end
assert called
# and be populated by the last write time
assert @session_store[:last_write]
read = false
write = false
resolver.read do
assert ActiveRecord::Base.connected_to?(role: :writing)
assert_predicate ActiveRecord::Base.lease_connection, :preventing_writes?
read = true
resolver.write do
assert ActiveRecord::Base.connected_to?(role: :writing)
assert_not_predicate ActiveRecord::Base.lease_connection, :preventing_writes?
write = true
end
end
assert write
assert read
end
def test_preventing_writes_works_in_a_threaded_environment
resolver = ActiveRecord::Middleware::DatabaseSelector::Resolver.new(@session, delay: 5.seconds)
inside_preventing = Concurrent::Event.new
finished_checking = Concurrent::Event.new
@session.update_last_write_timestamp
t1 = Thread.new do
resolver.read do
inside_preventing.wait
assert ActiveRecord::Base.connected_to?(role: :writing)
assert_predicate ActiveRecord::Base.lease_connection, :preventing_writes?
finished_checking.set
end
end
t2 = Thread.new do
resolver.write do
assert ActiveRecord::Base.connected_to?(role: :writing)
assert_not_predicate ActiveRecord::Base.lease_connection, :preventing_writes?
inside_preventing.set
finished_checking.wait
end
end
t3 = Thread.new do
resolver.read do
assert ActiveRecord::Base.connected_to?(role: :writing)
assert_predicate ActiveRecord::Base.lease_connection, :preventing_writes?
end
end
t1.join
t2.join
t3.join
end
def test_read_from_replica_with_no_delay
resolver = ActiveRecord::Middleware::DatabaseSelector::Resolver.new(@session, delay: 0.seconds)
# Session should start empty
assert_nil @session_store[:last_write]
called = false
resolver.write do
assert ActiveRecord::Base.connected_to?(role: :writing)
called = true
end
assert called
# and be populated by the last write time
assert @session_store[:last_write]
read = false
resolver.read do
assert ActiveRecord::Base.connected_to?(role: :reading)
read = true
end
assert read
end
def test_the_middleware_chooses_writing_role_with_POST_request
middleware = ActiveRecord::Middleware::DatabaseSelector.new(lambda { |env|
assert ActiveRecord::Base.connected_to?(role: :writing)
[200, {}, ["body"]]
})
cache = ActiveSupport::Cache::MemoryStore.new
middleware = ActionDispatch::Session::CacheStore.new(middleware, cache: cache, key: "_session_id")
assert_equal [200, {}, ["body"]], middleware.call("REQUEST_METHOD" => "POST")
end
def test_the_middleware_chooses_reading_role_with_GET_request
middleware = ActiveRecord::Middleware::DatabaseSelector.new(lambda { |env|
assert ActiveRecord::Base.connected_to?(role: :reading)
[200, {}, ["body"]]
})
cache = ActiveSupport::Cache::MemoryStore.new
middleware = ActionDispatch::Session::CacheStore.new(middleware, cache: cache, key: "_session_id")
assert_equal [200, {}, ["body"]], middleware.call("REQUEST_METHOD" => "GET")
end
class ReadonlyResolver < ActiveRecord::Middleware::DatabaseSelector::Resolver
def reading_request?(request)
true
end
end
def test_the_middleware_chooses_reading_role_with_POST_request_if_resolver_tells_it_to
middleware = ActiveRecord::Middleware::DatabaseSelector.new(lambda { |env|
assert ActiveRecord::Base.connected_to?(role: :reading)
[200, {}, ["body"]]
}, ReadonlyResolver)
cache = ActiveSupport::Cache::MemoryStore.new
middleware = ActionDispatch::Session::CacheStore.new(middleware, cache: cache, key: "_session_id")
assert_equal [200, {}, ["body"]], middleware.call("REQUEST_METHOD" => "POST")
end
end
end
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