Sync test DB from schema using its SHA1 #36870
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Moving this to 6.1 since what we'll backport will only be on parallel testing. |
We flip-flopped on this for a bit 馃槄. It's a bit of a change the close to release but we figured we'd rather only have one implementation to worry about in 6.0 rather than having a different methods of syncing for single test DB vs parallel. |
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| ActiveRecord::Base.establish_connection(configuration) | ||
| return false unless ActiveRecord::InternalMetadata.table_exists? | ||
| ActiveRecord::InternalMetadata[:schema_sha1] == schema_sha1(file) |
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Do we need to stop this information in the database? Can't it be a file on tmp?
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Good question 鉂わ笍
I think the database is the best place for it, we want to store this exactly per-database: my_app_test separate from my_app_development, my_app_test-1 separate from my_app_test-2 when using parallelism. So storing it in the database itself I think accomplishes this the best. It also handles databases being dropped/restored from backup/etc.
I also think it's similar enough to the other information we store in the DB: very similar to schema migrations (metadata about the "structure" of the DB) and somewhat similar to environment (it records the state at creation/load) that it "feels" right to me.
Previously, we used the migration status to determine whether the test database(s) needed to be reloaded from the schema. This worked in most cases, but if a schema.rb was modified outside of migrations or if a migration was rolled back, it would require a manual db:test:prepare. This commit updates load_schema to record the SHA1 of the loaded schema file inside of the ar_internal_metadata table. We can then use this SHA to determine whether we should reload the schema. This ensures that the test DB stays exactly in sync with the schema file, including rollbacks which fixes a test marked TODO.
Sync test DB from schema using its SHA1
Previously, we used the migration status to determine whether the test database(s) needed to be reloaded from the schema. This worked in most cases, but if a
schema.rbwas modified outside of migrations or if a migration was rolled back, it would require a manualdb:test:prepare.This commit updates load_schema to record the SHA1 of the loaded schema file inside the
ar_internal_metadatatable under a newschema_shakey. We can then use this SHA to determine whether we should reload the schema.This ensures that the test DB stays exactly in sync with the schema file, including rollbacks which fixes a test marked TODO.
This came from #36826 where the motivation was to speed up parallel test DB creation, but I think we should make this change first and there's enough motivation to want it for non-parallel DB creation 馃槃