Always save the latest available version of QuestionnaireStore.

[bitdivision]

What is the context of this PR?

Currently, we are able to read version 3 in production, but can only write version 2.

While making the changes to write version 3, it became clear that there is an issue around what version we are writing for the questionnaire store.

In a deployment as follows (I've represented the version of the data with data_version):

1. Instance running version 2 saves QuestionnaireStore. {version=2, data_version=2}
2. Instance running version 3 loads QuestionnaireStore with version 2, upgrades to version 3, and saves {version=3, data_version=3}
3. Instance running version 2 loads QuestionnaireStore with version 3, and saves with {version=3, data_version=2}

At this point we have a mismatched version number, which will cause errors when an application tries to load it.

To avoid this, we can ensure that we always write the latest version which the current code can write, rather than the highest possible version.

How to review

I have a branch which adds the writing functionality of version 3. This can be used to test it.

1. Checkout master, start a questionnaire
2. Checkout 2647-update-questionnaire-store-version-for-compression-and-new-answerstore-storage-format, restart server, continue questionnaire.
3. Checkout master, restart server, continue questionnaire.
4. You should see errors
5. Checkout this PR's branch, start a questionnaire
6. Checkout 2647-update-questionnaire-store-version-for-compression-and-new-answerstore-storage-format, merge this PR into it, continue your questionnaire.
7. Checkout this PR, continue your questionnaire
8. Checkout 2647-update-questionnaire-store-version-for-compression-and-new-answerstore-storage-format, continue questionnaire, and ensure it's all working

Checklist

• New static content marked up for translation
• Newly defined schema content included in eq-translations repo

[jonnyshaw89]

Are they also answers after submission and session store writes that need to be updated?

[bitdivision]

Are they also answers after submission and session store writes that need to be updated?

I think this only applies to QuestionnaireStore writes? This PR just fixes a defect in how the version was written.

Maybe I've missed something?

[bitdivision]

@ajmaddaford I've made a few changes to make it a bit clearer what's going on with the version of QuestionnaireStore.

[MebinAbraham]

Tested the scenarios and, the version seems to always match the data version. Checked the data in Postgres and all seems as expected.