In migration test, do inserts before some migrations to avoid empty tables

[dullbananas]

This would catch errors that only happen if some tables have at least one row, such as #5531

[momentary-lapse]

I can take this one

[momentary-lapse]

Are you considering any specific (common for diesel) approach to implement these test migrations, or this ticket assumes figuring it out?

[Nutomic]

The mentioned test is here. Implementing this would work more or less so:

• Set Options.limit to only run the first few migrations (enough to create tables for user, community, post, comment)
• Use raw sql to insert some rows (as diesel structs are not compatible with the old db schema)
• Run all the remaining migrations
• Read the inserted data with normal diesel functions (eg Post::read)
• Check that fields like post.title are unchanged
• Keep the remaining logic to check revert migration etc

[momentary-lapse]

Do you think it's worth to invest into a more extensible solution? Like, a module with test migrations that run after corresponding migration is finished?

[Nutomic]

Not sure what you mean, but its better to keep things simple and avoid unnecessary complexity.

[momentary-lapse]

Okay, I see that for now it's enough to add test data once. I've been thinking about situation when it's not enough, and you need to run, for instance, 10 migrations then add some test data, then next 15 migrations and add more data, then 20 and more data etc. But it's not the case

[dessalines]

I'm also not sure this would work, because it'd need custom tests after specific migrations have been run.

[Nutomic]

Its enough to check after all migrations are finished that the test data still exists.