Mnesia migrations with global lock on startup. Refs EventHub/EventHubBack#24

2026-07-07 17:54:29 +03:00
parent 6e1157134c
commit 7c5f2d26b8
5 changed files with 806 additions and 647 deletions
@@ -0,0 +1,63 @@
+-module(migration_engine_tests).
+-include_lib("eunit/include/eunit.hrl").
+-include("records.hrl").
+
+-define(LOCK_VERSION, "__migration_lock__").
+
+setup() ->
+  mnesia:stop(),
+  mnesia:delete_schema([node()]),
+  mnesia:create_schema([node()]),
+  mnesia:start(),
+  mnesia:create_table(schema_migration, [
+    {disc_copies, [node()]},
+    {attributes, record_info(fields, schema_migration)},
+    {type, set}
+  ]),
+  {ok, _} = migration_engine:start_link(),
+  ok.
+
+cleanup(_) ->
+  catch gen_server:stop(migration_engine),
+  catch mnesia:delete_table(schema_migration),
+  mnesia:stop(),
+  mnesia:delete_schema([node()]),
+  ok.
+
+migration_engine_test_() ->
+  {foreach, fun setup/0, fun cleanup/1, [
+    {"ensure_applied applies pending migrations", fun test_ensure_applied/0},
+    {"ensure_applied is idempotent", fun test_ensure_applied_idempotent/0},
+    {"lock record is not treated as migration", fun test_lock_not_applied/0},
+    {"join node waits until migrations applied", fun test_join_wait/0}
+  ]}.
+
+test_ensure_applied() ->
+  ?assertEqual(ok, migration_engine:ensure_applied()),
+  Status = migration_engine:status(),
+  ?assertEqual([], maps:get(pending, Status)),
+  Applied = maps:get(applied, Status),
+  ?assert(lists:member("20260501120000_base_schema", Applied)),
+  ?assert(lists:member("20260504150000_test_migration", Applied)).
+
+test_ensure_applied_idempotent() ->
+  ?assertEqual(ok, migration_engine:ensure_applied()),
+  ?assertEqual(ok, migration_engine:ensure_applied()).
+
+test_lock_not_applied() ->
+  ?assertEqual(ok, migration_engine:ensure_applied()),
+  Status = migration_engine:status(),
+  ?assertNot(lists:member(?LOCK_VERSION, maps:get(applied, Status))).
+
+test_join_wait() ->
+  Now = calendar:universal_time(),
+  mnesia:dirty_write(#schema_migration{version = ?LOCK_VERSION, applied_at = Now}),
+  spawn(fun() ->
+    timer:sleep(100),
+    mnesia:dirty_write(#schema_migration{
+      version = "20260501120000_base_schema", applied_at = Now}),
+    mnesia:dirty_write(#schema_migration{
+      version = "20260504150000_test_migration", applied_at = Now}),
+    mnesia:dirty_delete({schema_migration, ?LOCK_VERSION})
+  end),
+  ?assertEqual(ok, migration_engine:ensure_applied()).