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GeezerVison is showing github.com — Add before_transaction/1 and after_transaction/1 migration callbacks … · elixir-ecto/ecto_sql@bf126d6

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  • lib/ecto
    • migration.ex
    • migrator.ex
  • test
    • ecto
      • migrator_test.exs
    • support
      • test_repo.exs
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‎lib/ecto/migration.ex‎

Copy file name to clipboardExpand all lines: lib/ecto/migration.ex
+55-1Lines changed: 55 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -405,6 +405,37 @@ defmodule Ecto.Migration do
405405
Then in your migrations you can `use MyApp.Migration` to share this behavior
406406
among all your migrations.
407407
408+
### Before and after the transaction
409+
410+
Some commands only work outside of a transaction. For example, SQLite
411+
ignores `PRAGMA foreign_keys` inside one, but its
412+
[procedure for changing a table](https://sqlite.org/lang_altertable.html#making_other_kinds_of_table_schema_changes)
413+
requires it to be off. `c:before_transaction/1` and `c:after_transaction/1`
414+
run around the migration transaction, on the same connection, so a setting
415+
made in the first applies to the transaction and the second can restore it:
416+
417+
defmodule MyApp.Migration do
418+
defmacro __using__(_) do
419+
quote do
420+
use Ecto.Migration
421+
422+
def before_transaction(repo) do
423+
repo.query!("PRAGMA foreign_keys = OFF")
424+
end
425+
426+
def after_transaction(repo) do
427+
# Restore the configured value, do not turn it on unconditionally
428+
if Keyword.get(repo.config(), :foreign_keys, :on) == :on do
429+
repo.query!("PRAGMA foreign_keys = ON")
430+
end
431+
end
432+
end
433+
end
434+
end
435+
436+
Like `c:after_begin/0` and `c:before_commit/0`, they are not run when the
437+
migration does not run in a transaction.
438+
408439
## Additional resources
409440
410441
* The [Safe Ecto Migrations guide](safe_migrations.md)
@@ -426,7 +457,30 @@ defmodule Ecto.Migration do
426457
consider both the up *and* down cases of the migration.
427458
"""
428459
@callback before_commit() :: term
429-
@optional_callbacks after_begin: 0, before_commit: 0
460+
461+
@doc """
462+
Code to run before the migration transaction is opened.
463+
464+
It runs on the same connection as the transaction and receives the repo.
465+
`repo/0`, `prefix/0`, `direction/0`, `execute/1` and `flush/0` are not
466+
available.
467+
"""
468+
@callback before_transaction(repo :: Ecto.Repo.t()) :: term
469+
470+
@doc """
471+
Code to run after the migration transaction is closed.
472+
473+
It runs on the same connection as the transaction, whether the transaction
474+
was committed or rolled back and even if `c:before_transaction/1` raised,
475+
so that what it changed can always be restored. `repo/0`, `prefix/0`,
476+
`direction/0`, `execute/1` and `flush/0` are not available.
477+
"""
478+
@callback after_transaction(repo :: Ecto.Repo.t()) :: term
479+
480+
@optional_callbacks after_begin: 0,
481+
before_commit: 0,
482+
before_transaction: 1,
483+
after_transaction: 1
430484

431485
defmodule Index do
432486
@moduledoc """
Collapse file

‎lib/ecto/migrator.ex‎

Copy file name to clipboardExpand all lines: lib/ecto/migrator.ex
+28-3Lines changed: 28 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -353,15 +353,40 @@ defmodule Ecto.Migrator do
353353
not repo.__adapter__().supports_ddl_transaction?() do
354354
fun.()
355355
else
356-
{:ok, result} = repo.transaction(fun, log: migrator_log(opts), timeout: :infinity)
357-
358-
result
356+
run_in_transaction(repo, module, fun, opts)
359357
end
360358
catch
361359
kind, reason ->
362360
{kind, reason, __STACKTRACE__}
363361
end
364362

363+
defp run_in_transaction(repo, module, fun, opts) do
364+
transaction = fn ->
365+
{:ok, result} = repo.transaction(fun, log: migrator_log(opts), timeout: :infinity)
366+
result
367+
end
368+
369+
if function_exported?(module, :before_transaction, 1) or
370+
function_exported?(module, :after_transaction, 1) do
371+
repo.checkout(
372+
fn ->
373+
try do
374+
if function_exported?(module, :before_transaction, 1),
375+
do: module.before_transaction(repo)
376+
377+
transaction.()
378+
after
379+
if function_exported?(module, :after_transaction, 1),
380+
do: module.after_transaction(repo)
381+
end
382+
end,
383+
timeout: :infinity
384+
)
385+
else
386+
transaction.()
387+
end
388+
end
389+
365390
defp attempt(repo, config, version, module, direction, operation, reference, opts) do
366391
if Code.ensure_loaded?(module) and function_exported?(module, operation, 0) do
367392
Runner.run(repo, config, version, module, direction, operation, reference, opts)
Collapse file

‎test/ecto/migrator_test.exs‎

Copy file name to clipboardExpand all lines: test/ecto/migrator_test.exs
+172Lines changed: 172 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -130,6 +130,77 @@ defmodule Ecto.MigratorTest do
130130
end
131131
end
132132

133+
defmodule Events do
134+
def record(name, repo \\ nil) do
135+
notify(
136+
{:migration_event, {name, repo, TestRepo.in_transaction?(), TestRepo.checked_out?()}}
137+
)
138+
end
139+
140+
def notify(message) do
141+
config = Application.get_env(:ecto_sql, EctoSQL.TestAdapter, [])
142+
send(Keyword.fetch!(config, :test_process), message)
143+
end
144+
end
145+
146+
defmodule MigrationWithBeforeAndAfterTransaction do
147+
use Ecto.Migration
148+
149+
def before_transaction(repo), do: Events.record(:before_transaction, repo)
150+
def after_begin, do: Events.record(:after_begin)
151+
def up, do: Events.record(:up)
152+
def down, do: Events.record(:down)
153+
def before_commit, do: Events.record(:before_commit)
154+
def after_transaction(repo), do: Events.record(:after_transaction, repo)
155+
end
156+
157+
defmodule MigrationWithBeforeAndAfterTransactionAndNoTransaction do
158+
use Ecto.Migration
159+
160+
@disable_ddl_transaction true
161+
162+
def before_transaction(repo), do: Events.record(:before_transaction, repo)
163+
def up, do: Events.record(:up)
164+
def after_transaction(repo), do: Events.record(:after_transaction, repo)
165+
end
166+
167+
defmodule MigrationWithoutBeforeAndAfterTransaction do
168+
use Ecto.Migration
169+
170+
def up, do: Events.record(:up)
171+
end
172+
173+
defmodule MigrationWithAfterTransactionOnly do
174+
use Ecto.Migration
175+
176+
def up, do: Events.record(:up)
177+
def after_transaction(repo), do: Events.record(:after_transaction, repo)
178+
end
179+
180+
defmodule MigrationWithFailingUp do
181+
use Ecto.Migration
182+
183+
def before_transaction(repo), do: Events.record(:before_transaction, repo)
184+
def up, do: raise("up failed")
185+
def after_transaction(repo), do: Events.record(:after_transaction, repo)
186+
end
187+
188+
defmodule MigrationWithFailingBeforeTransaction do
189+
use Ecto.Migration
190+
191+
def before_transaction(_repo), do: raise("before_transaction failed")
192+
def up, do: Events.record(:up)
193+
def after_transaction(repo), do: Events.record(:after_transaction, repo)
194+
end
195+
196+
defmodule MigrationWithDynamicRepoCallbacks do
197+
use Ecto.Migration
198+
199+
def before_transaction(repo), do: Events.notify({:dynamic_repo, repo.get_dynamic_repo()})
200+
201+
def up, do: :ok
202+
end
203+
133204
defmodule ExecuteOneAnonymousFunctionMigration do
134205
use Ecto.Migration
135206

@@ -920,6 +991,107 @@ defmodule Ecto.MigratorTest do
920991
end
921992
end
922993

994+
describe "migration callbacks around the transaction" do
995+
setup do
996+
put_test_adapter_config(supports_ddl_transaction?: true, test_process: self())
997+
end
998+
999+
defp events(acc \\ []) do
1000+
receive do
1001+
{:migration_event, event} -> events([event | acc])
1002+
after
1003+
0 -> Enum.reverse(acc)
1004+
end
1005+
end
1006+
1007+
test "run around the transaction, on a checked out connection, going up" do
1008+
assert up(TestRepo, 10, MigrationWithBeforeAndAfterTransaction, log: false) == :ok
1009+
1010+
assert events() == [
1011+
{:before_transaction, TestRepo, false, true},
1012+
{:after_begin, nil, true, true},
1013+
{:up, nil, true, true},
1014+
{:before_commit, nil, true, true},
1015+
{:after_transaction, TestRepo, false, true}
1016+
]
1017+
1018+
assert {10, nil} in MigrationsAgent.get()
1019+
end
1020+
1021+
test "run around the transaction, on a checked out connection, going down" do
1022+
assert up(TestRepo, 10, MigrationWithBeforeAndAfterTransaction, log: false) == :ok
1023+
events()
1024+
1025+
assert down(TestRepo, 10, MigrationWithBeforeAndAfterTransaction, log: false) == :ok
1026+
1027+
assert events() == [
1028+
{:before_transaction, TestRepo, false, true},
1029+
{:after_begin, nil, true, true},
1030+
{:down, nil, true, true},
1031+
{:before_commit, nil, true, true},
1032+
{:after_transaction, TestRepo, false, true}
1033+
]
1034+
1035+
refute {10, nil} in MigrationsAgent.get()
1036+
end
1037+
1038+
test "run for the dynamic repo" do
1039+
assert up(TestRepo, 10, MigrationWithDynamicRepoCallbacks,
1040+
log: false,
1041+
dynamic_repo: :tenant_db
1042+
) == :ok
1043+
1044+
assert_received {:dynamic_repo, :tenant_db}
1045+
end
1046+
1047+
test "do not check out a connection when there are none" do
1048+
assert up(TestRepo, 10, MigrationWithoutBeforeAndAfterTransaction, log: false) == :ok
1049+
assert events() == [{:up, nil, true, false}]
1050+
end
1051+
1052+
test "run when only after_transaction is defined" do
1053+
assert up(TestRepo, 10, MigrationWithAfterTransactionOnly, log: false) == :ok
1054+
1055+
assert events() == [
1056+
{:up, nil, true, true},
1057+
{:after_transaction, TestRepo, false, true}
1058+
]
1059+
end
1060+
1061+
test "are not run when the transaction is disabled" do
1062+
assert up(TestRepo, 10, MigrationWithBeforeAndAfterTransactionAndNoTransaction, log: false) ==
1063+
:ok
1064+
1065+
assert events() == [{:up, nil, false, false}]
1066+
end
1067+
1068+
test "are not run when the adapter does not support transactions" do
1069+
put_test_adapter_config(supports_ddl_transaction?: false, test_process: self())
1070+
1071+
assert up(TestRepo, 10, MigrationWithBeforeAndAfterTransaction, log: false) == :ok
1072+
assert events() == [{:up, nil, false, false}]
1073+
end
1074+
1075+
test "still run after_transaction when the migration fails" do
1076+
assert_raise RuntimeError, "up failed", fn ->
1077+
up(TestRepo, 10, MigrationWithFailingUp, log: false)
1078+
end
1079+
1080+
assert events() == [
1081+
{:before_transaction, TestRepo, false, true},
1082+
{:after_transaction, TestRepo, false, true}
1083+
]
1084+
end
1085+
1086+
test "run after_transaction but not the migration when before_transaction fails" do
1087+
assert_raise RuntimeError, "before_transaction failed", fn ->
1088+
up(TestRepo, 10, MigrationWithFailingBeforeTransaction, log: false)
1089+
end
1090+
1091+
assert events() == [{:after_transaction, TestRepo, false, true}]
1092+
end
1093+
end
1094+
9231095
describe "migrations_path" do
9241096
test "is inferred from the repository name" do
9251097
path = migrations_path(TestRepo)
Collapse file

‎test/support/test_repo.exs‎

Copy file name to clipboardExpand all lines: test/support/test_repo.exs
+9-2Lines changed: 9 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -33,8 +33,6 @@ defmodule EctoSQL.TestAdapter do
3333
{:ok, child_spec, %{meta: :meta}}
3434
end
3535

36-
def checkout(_, _, _), do: raise("not implemented")
37-
def checked_out?(_), do: raise("not implemented")
3836
def delete(_, _, _, _, _), do: raise("not implemented")
3937
def insert_all(_, _, _, _, _, _, _, _), do: raise("not implemented")
4038
def rollback(_, _), do: raise("not implemented")
@@ -75,6 +73,15 @@ defmodule EctoSQL.TestAdapter do
7573
{:ok, []}
7674
end
7775

76+
def checked_out?(_), do: Process.get(:checked_out?) || false
77+
78+
def checkout(_, _opts, fun) do
79+
Process.put(:checked_out?, true)
80+
fun.()
81+
after
82+
Process.put(:checked_out?, false)
83+
end
84+
7885
def in_transaction?(_), do: Process.get(:in_transaction?) || false
7986

8087
def transaction(mod, _opts, fun) do

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