Make YARD documentation idempotent

[KaanOzkan]

Motivation

Resolves #1345

Problem: YARD.parse stores parsed documentation into a registry that's persisted. So depending on the parsing order of the gems documentation may change. If a previous gem has documentation for a constant/method definition it'll be included in the current gem's documentation too. However, in another run if that previous gem is parsed too late its documentation won't be available.

Implementation

In this PR we reset the YARD registry everytime we parse a gem's documentation to ensure only the documentation from that gem is included in the output. This means parsing order has no effect in the RBIs created and that documentation generation is idempotent.

As a result of this change duplicated RBI entries will not contain as much documentation as before. For example, when a gem defines a method on the global namespace tapioca would define class Object on the gem RBI. If a previously processed gem had documentation for Object it'd get imported into that gem, example. In some cases like the example the documentation didn't even make sense. It's coming from Rails.

We initially tried to keep the documentation for each gem by parsing the documentation of all gems before any RBI generation. However, this increases the runtime since parsing isn't done in parallel anymore.

Tests

Included

[paracycle]

Nice catch!

[egiurleo]

🎉