fix: run migrations in series

[klassicd]

Fixes #168

Replaces async.each with async.eachSeries in automigrate() and autoudate() so migrations are run in a series instead of in parallel. This enforces the model order so foreign key constructs with Postgres are possible.

Previously it was impossible to enforce order in Loopback 4 using the models option to migrateSchema({models: ['m1', 'm2']}) as documented here https://loopback.io/doc/en/lb4/todo-list-tutorial-sqldb.html

Checklist

👉 Read and sign the CLA (Contributor License Agreement) 👈

• npm test passes on your machine
• New tests added or existing tests modified to cover all changes
• Code conforms with the style guide
• Commit messages are following our guidelines

[dhmlau]

@klassicd, thanks for your PR. Your changes LGTM. I'd like to get at least one more review before landing. Thanks.

[dhmlau]

@slnode test please

[montera82]

LGTM

[jannyHou]

@klassicd Thank you for the contribution, looks reasonable to me. I left a minor comment for the test.

[jannyHou]

any reason change m2 to m3?

[klassicd]

Previously there was only a single table m1 attached and m2 was un-attached. The new test (line #55) expects two tables created in a series. So I refactored two tables m1 and m2 to be attached by default, and here to look for an un-attached table m3.

[jannyHou]

Thank you for the explanation, fair enough.

[jannyHou]

Thank you @klassicd approved. I can help you rebase the PR and will double check the downstream failures.

[klassicd]

Yes @jannyHou that would help, thank you.

[jannyHou]

@slnode test please

[dhmlau]

@klassicd, thanks for your contribution. Your PR has landed!