#194 Switch to peer dependencies for @theia dependencies

[ndoschek]

Part of eclipse-emfcloud/emfcloud#194

Contributed on behalf of STMicroelectronics

[tortmayr]

Thanks Nina, I'm looking forward to using peer Dependencies for core Theia extensions. This should help in resolving the dependency hell in some of our downstream projects.
However, I noticed a couple of issues:

The example packages still reference Theia extensions as dependencies instead of peerDependencies. We should fix this to ensure that the browser-app is the single source of truth and has the sole responsibility of providing the actual used Theia versions.

Also, to fully support peerDependencies in donwstream projects we need a fix that is only available with Theia >=1.33. (eclipse-theia/theia@2ec7d87). Without this fix the module loading order of Theia extensions that rely on peer dependencies might get mixed up and break the application in certain cases.

We need to update the minimum Theia verison requirements anyways as I'm fairly certain that we are not compatible with Theia version 1.0.0 since quite a long time 😉
I would suggest to directly update the minimum Version to 1.33.0

[tortmayr]

Thanks for the fast update. LGTM 👍🏼

One last thing, not sure if it's an issue but if I execute yarn theia check:dependencies I get two errors regarding the ws package:

❯ yarn theia check:dependencies
yarn run v1.22.19
$ /home/tobias/Git/OpenSource/emfcloud/emfcloud-modelserver-theia/node_modules/.bin/theia check:dependencies
✅ Found 7 workspaces
✅ Found 1285 dependencies
🟠 Found 2 issues

#1  ws in @eclipse-emfcloud/modelserver-theia [not-hoisted]
    error Dependency ws is not hoisted.
    8.5.0 in packages/modelserver-theia/node_modules/ws/package.json
    7.5.9 in node_modules/ws/package.json

#2  ws in @eclipse-emfcloud/modelserver-theia [multiple-versions]
    error Multiple versions of dependency ws found.
    8.5.0 in packages/modelserver-theia/node_modules/ws/package.json
    7.5.9 in node_modules/ws/package.json


ℹ️  Use yarn why <package-name> to find out why those multiple versions of a package are pulled.
ℹ️  Try to resolve those issues by finding package versions along the dependency chain that depend on compatible versions.
ℹ️  Use resolutions in your root package.json to force specific versions as a last resort.

[tortmayr]

And on a side note, in GLSP we maintain a Theia version compability matrix in the README. Maybe we do the same here.

[ndoschek]

Thanks @tortmayr, will keep that in mind, regarding the compat section, that's a good point, we will add that with #76