Add Cask::Config RBI compiler

This is a naive attempt at creating an RBI compiler for the
`Cask::Config` class. `Config` contains methods like `appdir` that
are defined dynamically using the class's default values and Sorbet
doesn't understand that these methods exist or what their return
types are. This compiler works as expected and gets the job done but
I know basically nothing about Tapioca, so there may be a better way
of doing this.

For what it's worth, this isn't an issue right now but Sorbet will
surface an error once `Cask::DSL` is updated to `typed: strict` (i.e.,
`Method appdir does not exist on Cask::Config`). That's something
I've been working on and this compiler is intended as a way of
preemptively resolving that Sorbet error, so I can move forward with
the `Cask::DSL` type signature work.

Library/Homebrew/sorbet/rbi/dsl/cask/config.rbi

@@ -0,0 +1,58 @@
+# typed: true
+
+# DO NOT EDIT MANUALLY
+# This is an autogenerated file for dynamic methods in `Cask::Config`.
+# Please instead update this file by running `bin/tapioca dsl Cask::Config`.
+
+
+module Cask
+  class Config
+    sig { returns(String) }
+    def appdir; end
+
+    sig { returns(String) }
+    def audio_unit_plugindir; end
+
+    sig { returns(String) }
+    def colorpickerdir; end
+
+    sig { returns(String) }
+    def dictionarydir; end
+
+    sig { returns(String) }
+    def fontdir; end
+
+    sig { returns(String) }
+    def input_methoddir; end
+
+    sig { returns(String) }
+    def internet_plugindir; end
+
+    sig { returns(String) }
+    def keyboard_layoutdir; end
+
+    sig { returns(T::Array[String]) }
+    def languages; end
+
+    sig { returns(String) }
+    def mdimporterdir; end
+
+    sig { returns(String) }
+    def prefpanedir; end
+
+    sig { returns(String) }
+    def qlplugindir; end
+
+    sig { returns(String) }
+    def screen_saverdir; end
+
+    sig { returns(String) }
+    def servicedir; end
+
+    sig { returns(String) }
+    def vst3_plugindir; end
+
+    sig { returns(String) }
+    def vst_plugindir; end
+  end
+end

Library/Homebrew/sorbet/tapioca/compilers/cask/config.rb

@@ -0,0 +1,37 @@
+# typed: strict
+# frozen_string_literal: true
+
+require_relative "../../../../global"
+require "cask/config"
+
+module Tapioca
+  module Compilers
+    class CaskConfig < Tapioca::Dsl::Compiler
+      ConstantType = type_member { { fixed: Module } }
+
+      sig { override.returns(T::Enumerable[Module]) }
+      def self.gather_constants = [Cask::Config]
+
+      sig { override.void }
+      def decorate
+        root.create_module("Cask") do |mod|
+          mod.create_class("Config") do |klass|
+            Cask::Config.defaults.each do |key, value|
+              return_type = if key == :languages
+                # :languages is a `LazyObject`, so it lazily evaluates to an
+                # array of strings when a method is called on it.
+                "T::Array[String]"
+              elsif key.end_with?("?")
+                "T::Boolean"
+              else
+                value.class.to_s
+              end
+
+              klass.create_method(key.to_s, return_type:, class_method: false)
+            end
+          end
+        end
+      end
+    end
+  end
+end