Merge pull request #23078 from Homebrew/noop-type-constructors

Return a shared type instance from type constructors when runtime checking is disabled

Library/Homebrew/standalone/sorbet.rb

@@ -83,10 +83,43 @@ else
     end
   end
 
+  # Redefine type constructors to return a shared untyped instance: their
+  # results are only consumed by runtime checking, which is disabled.
+  # @private
+  module TNoOpTypeConstructors
+    # A union with NilClass rather than plain untyped: `prop`/`const` infer
+    # optionality from their type argument, so nilable props must still look
+    # nilable or serialising them while nil raises.
+    # Not frozen: `Union` memoises internally on first use.
+    # rubocop:disable Style/MutableConstant
+    UNTYPED = T::Types::Union.new([T::Types::Untyped.new, T::Types::Simple.new(NilClass)])
+    # rubocop:enable Style/MutableConstant
+
+    def nilable(_type) = UNTYPED
+    def any(*_types) = UNTYPED
+    def all(*_types) = UNTYPED
+    def class_of(_klass) = UNTYPED
+    def untyped = UNTYPED
+    def anything = UNTYPED
+    def self_type = UNTYPED
+    def attached_class = UNTYPED
+    def type_parameter(_name) = UNTYPED
+  end
+
+  # @private
+  module TNoOpTypeIndex
+    def [](*_types) = TNoOpTypeConstructors::UNTYPED
+  end
+
+  [T::Array, T::Hash, T::Set, T::Range, T::Enumerable, T::Enumerator].each do |mod|
+    mod.singleton_class.prepend(TNoOpTypeIndex)
+  end
+
   # @private
   module T
     class << self
       prepend TNoChecks
+      prepend TNoOpTypeConstructors
     end
 
     # Redefine `T.sig` to be a no-op.