apollo-datasource-rest should declare graphql as peerDependency

[Grmiade]

apollo-datasource-rest needs apollo-server-errors which has graphql as peerDependency.
So apollo-datasource-rest should also declare graphql as peerDependency in order to not breaking the chain.

[glasser]

This one I don't understand. a-d-r does not use graphql (it actually has literally nothing to do with GraphQL, it's just a caching HTTP client). It does correctly depend on apollo-server-errors which correctly peer deps on graphql. Why would everything that depends on apollo-server-errors also need to peer dep on graphql?

[Grmiade]

When we depend of a package with a peer dependency we have to declare it as dependency.
Here apollo-datasource-rest depends of apollo-server-errors with graphql as peer dependency.
But apollo-datasource-rest doesn't need graphql because it doesn't use it. So instead of declare it as dependency we should declare it as peer dependency, in order to indicate to the packages which use apollo-datasource-rest they should install graphql, not for apollo-datasource-rest but for apollo-server-errors, it's what I called the "chain".

PnP being more strict with this kind of stuff, this kind of errors are raised:

Error: apollo-server-errors tried to access graphql (a peer dependency) but it isn't provided by its ancestors; this makes the require call ambiguous and unsound.

Required package: graphql
Required by: apollo-server-errors@virtual:1a27f047ab26746f7fed08c476ddf4561a87794f226019306e917a0a4ea8babfbb3fbc3a9852e50021103b37e9a00084a79a6cb0373b52642ae7377b88868c26#npm:3.3.1 (via /usr/src/app/.yarn/__virtual__/apollo-server-errors-virtual-cf59f2326d/0/cache/apollo-server-errors-npm-3.3.1-f3e7ce6ccc-d09b66e7ac.zip/node_modules/apollo-server-errors/dist/)

Ancestor breaking the chain: apollo-datasource-rest@npm:3.5.3
Require stack:
- /usr/src/app/.yarn/__virtual__/apollo-server-errors-virtual-cf59f2326d/0/cache/apollo-server-errors-npm-3.3.1-f3e7ce6ccc-d09b66e7ac.zip/node_modules/apollo-server-errors/dist/index.js
- /usr/src/app/.yarn/cache/apollo-datasource-rest-npm-3.5.3-1a27f047ab-faed1fb8b1.zip/node_modules/apollo-datasource-rest/dist/RESTDataSource.js
- /usr/src/app/.yarn/cache/apollo-datasource-rest-npm-3.5.3-1a27f047ab-faed1fb8b1.zip/node_modules/apollo-datasource-rest/dist/index.js

[glasser]

Ah hmm. I suppose that makes sense, although it's a bit strange.

[Grmiade]

Thanks a lot @glasser for the 4 issues 💪