Fix react-native example based expo

[msotnikov]

This PR contains

Updated example for react-native based on Expo.

Main changes at 01.09.2022:

1. Updated versions expo@46.0.9, pouchdb@7.3.0, react@18.2.0, react-native@0.69.2
2. Fixed sync with couchdb instanance (you need your own)
3. Some refactoring

[pubkey]

A main reason for having these example projects, is to know when a change on the rxdb code breaks compatibility.
So I do not want to install rxdb from npm but it should use the build rxdb bundle. Also having a fixed version there would mean that someone has to come and update it on each rxdb release.

[msotnikov]

Ok, changed back. Added comment in readme.md.

[pubkey]

Can you update this line https://github.com/pubkey/rxdb/blob/master/.github/workflows/main.yml#L450
So that it does use the node version from the node-version-file: '.nvmrc' like in the other ci tasks.

[msotnikov]

expo-cli doesn't support node 18. expo/expo-cli#4478

[pubkey]

I see.
I am not sure if we should merge this then. Because we increase the expo version but decrease the react-native version, which does not lead to any benefit.

[msotnikov]

I see. I am not sure if we should merge this then. Because we increase the expo version but decrease the react-native version, which does not lead to any benefit.

But current code don't work any case :-)

Now updated only expo-cli. I leave old expo package and it have recommendations https://docs.expo.dev/versions/latest/#each-expo-sdk-version-depends-on-a. It was downgraded to prevent notification.

I'll try to update all deps

[msotnikov]

With jest-expo >= 44 tests passes, but finishes with seg fauilt (yarn and npm same). Now its works.

[pubkey]

Replication does not work because you switched from the pouchdb RxStorage to the memory RxStorage.
But the replication code uses the CouchDB replication protocol which only works with PouchDB RxStorage.

[pubkey]

Is there a reason why you switched to the memory adapter?
Because PouchDB is the only persistent RxStorage for react native, so the whole reason for the react-native example is to explain how to store data in it with the PouchDB RxStorage.

[msotnikov]

Is there a reason why you switched to the memory adapter? Because PouchDB is the only persistent RxStorage for react native, so the whole reason for the react-native example is to explain how to store data in it with the PouchDB RxStorage.

The entire PouchDb ecosystem is very outdated. For example, pouchdb-adapter-asyncstorage uses the deprecated async-storage (it was moved to community package). I had patched that package and fix that - the persistance works, but it doesn't fix sync. I tried to find working packages, but only the sqlite package with a bunch of crutches worked.

So, for this PR, we should deside what requirements are needed:

• persistence?
• sync throught http?
• ... ?

[pubkey]

Yes both is needed. The reason for making the react native example was to show that RxDB can work with the react-native SQLite storage.
We can switch from couchdb-sync to the rxdb replication of course.

I assume this PR is made in context of the premium tasks, is that correct?

[msotnikov]

Yes both is needed. The reason for making the react native example was to show that RxDB can work with the react-native SQLite storage. We can switch from couchdb-sync to the rxdb replication of course.

I assume this PR is made in context of the premium tasks, is that correct?

Previous version doesn't use sqlite, it uses asyncstorage.

I have some success with custom version of pouchdb-adapter-react-native-sqlite in my project. But yes, I want to try your version of sqlite connector because, as I mention before, the whole pouchdb ecosystem is outdated.

I'll try to change the adapter to sqlite in this example project.

[msotnikov]

Recent changes:

1. Dependencies updated to current versions - expo@46.0.9, pouchdb@7.3.0, react@18.2.0, react-native@0.69.2
2. Sync has fixed and tested with couchdb@3.2.2 instance (not included). Also, tested with pouchdb-server@4.2.2 - doesn't work.

There is no persistance functionality. Pouchdb need a crunches and Sqlite need a native modules to work. I don't want to deal with it for Expo. My suggestion is - rename this module to react-native-expo and leave as is in this PR. And create a new one with bare react-native.

[pubkey]

Strange error, I restarted the failed CI test.

[msotnikov]

I removed the cache settings. In any case, there is no package-lock file. And if I understood you correctly - you want to always have fresh packages.

The buggy jest and CI. I don't know how to fix it. Tests passed locally. Lost my patience. I'll be back later.

[msotnikov]

So... Now we will test database.

[pubkey]

Please pin all dependencies, always. This goes for the npm modules and also for docker image versions etc.

[msotnikov]

fixed

[pubkey]

The code looks good to me.
What is the state of the sync now? I see it connects to 'http://admin:mysecret1@localhost:5984' but there is nothing started at this port.
As far as I remember the pouchdb sync did work before, or was it broken anyway?

[msotnikov]

The code looks good to me. What is the state of the sync now? I see it connects to 'http://admin:mysecret1@localhost:5984' but there is nothing started at this port. As far as I remember the pouchdb sync did work before, or was it broken anyway?

There was the similar code before^
const syncURL = 'http://localhost:10102/'; // Replace localhost with a public ip address!

I haven't seen this code works. I haven't seen any server side also.

[pubkey]

Ah, you are right, sorry havent seen that there never was a server.
So I can merge this now?

[msotnikov]

Counting for it :-)

[pubkey]

Merged, thank you for your work.
You can ping me in discord for the access to the premium plugins.