blob: f89c26532df8c1c4e9eb6488972b7cf0ba1c9143 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
require 'cases/helper'
unless ActiveRecord::Base.connection.supports_transaction_isolation?
class TransactionIsolationUnsupportedTest < ActiveRecord::TestCase
self.use_transactional_fixtures = false
class Tag < ActiveRecord::Base
end
test "setting the isolation level raises an error" do
assert_raises(ActiveRecord::TransactionIsolationError) do
Tag.transaction(isolation: :serializable) { }
end
end
end
end
if ActiveRecord::Base.connection.supports_transaction_isolation?
class TransactionIsolationTest < ActiveRecord::TestCase
self.use_transactional_fixtures = false
class Tag < ActiveRecord::Base
self.table_name = 'tags'
end
class Tag2 < ActiveRecord::Base
self.table_name = 'tags'
end
setup do
Tag.establish_connection :arunit
Tag2.establish_connection :arunit
Tag.destroy_all
end
# It is impossible to properly test read uncommitted. The SQL standard only
# specifies what must not happen at a certain level, not what must happen. At
# the read uncommitted level, there is nothing that must not happen.
if ActiveRecord::Base.connection.transaction_isolation_levels.include?(:read_uncommitted)
test "read uncommitted" do
Tag.transaction(isolation: :read_uncommitted) do
assert_equal 0, Tag.count
Tag2.create
assert_equal 1, Tag.count
end
end
end
# We are testing that a dirty read does not happen
test "read committed" do
Tag.transaction(isolation: :read_committed) do
assert_equal 0, Tag.count
Tag2.transaction do
Tag2.create
assert_equal 0, Tag.count
end
end
assert_equal 1, Tag.count
end
# We are testing that a nonrepeatable read does not happen
if ActiveRecord::Base.connection.transaction_isolation_levels.include?(:repeatable_read)
test "repeatable read" do
tag = Tag.create(name: 'jon')
Tag.transaction(isolation: :repeatable_read) do
tag.reload
Tag2.find(tag.id).update(name: 'emily')
tag.reload
assert_equal 'jon', tag.name
end
tag.reload
assert_equal 'emily', tag.name
end
end
# We are only testing that there are no errors because it's too hard to
# test serializable. Databases behave differently to enforce the serializability
# constraint.
test "serializable" do
Tag.transaction(isolation: :serializable) do
Tag.create
end
end
test "setting isolation when joining a transaction raises an error" do
Tag.transaction do
assert_raises(ActiveRecord::TransactionIsolationError) do
Tag.transaction(isolation: :serializable) { }
end
end
end
test "setting isolation when starting a nested transaction raises error" do
Tag.transaction do
assert_raises(ActiveRecord::TransactionIsolationError) do
Tag.transaction(requires_new: true, isolation: :serializable) { }
end
end
end
end
end
|
