Fix type signatures.

Library/Homebrew/downloadable.rb

@@ -11,13 +11,13 @@ module Downloadable
 
   abstract!
 
-  sig { returns(T.nilable(URL)) }
+  sig { overridable.returns(T.nilable(URL)) }
   attr_reader :url
 
-  sig { returns(T.nilable(Checksum)) }
+  sig { overridable.returns(T.nilable(Checksum)) }
   attr_reader :checksum
 
-  sig { returns(T::Array[String]) }
+  sig { overridable.returns(T::Array[String]) }
   attr_reader :mirrors
 
   sig { void }
@@ -32,7 +32,7 @@ module Downloadable
     @version = @version.dup
   end
 
-  sig { returns(T.self_type) }
+  sig { overridable.returns(T.self_type) }
   def freeze
     @checksum.freeze
     @mirrors.freeze
@@ -48,22 +48,22 @@ module Downloadable
     T.must(self.class.name&.split("::")&.last).gsub(/([[:lower:]])([[:upper:]])/, '\1 \2').downcase
   end
 
-  sig { returns(T::Boolean) }
+  sig(:final) { returns(T::Boolean) }
   def downloaded?
     cached_download.exist?
   end
 
-  sig { returns(Pathname) }
+  sig { overridable.returns(Pathname) }
   def cached_download
     downloader.cached_location
   end
 
-  sig { void }
+  sig { overridable.void }
   def clear_cache
     downloader.clear_cache
   end
 
-  sig { returns(T.nilable(Version)) }
+  sig { overridable.returns(T.nilable(Version)) }
   def version
     return @version if @version && !@version.null?
 

Library/Homebrew/resource.rb

@@ -203,7 +203,7 @@ class Resource
     @download_strategy = @url.download_strategy
   end
 
-  sig { params(val: T.nilable(T.any(String, Version))).returns(T.nilable(Version)) }
+  sig { override.params(val: T.nilable(T.any(String, Version))).returns(T.nilable(Version)) }
   def version(val = nil)
     return super() if val.nil?
 

Library/Homebrew/retryable_download.rb

@@ -9,6 +9,15 @@ module Homebrew
     attr_reader :downloadable
     private :downloadable
 
+    sig { override.returns(T.nilable(URL)) }
+    def url = downloadable.url
+
+    sig { override.returns(T.nilable(Checksum)) }
+    def checksum = downloadable.checksum
+
+    sig { override.returns(T::Array[String]) }
+    def mirrors = downloadable.mirrors
+
     sig { params(downloadable: Downloadable, tries: Integer).void }
     def initialize(downloadable, tries: 3)
       super()
@@ -24,12 +33,21 @@ module Homebrew
     sig { override.returns(String) }
     def download_type = downloadable.download_type
 
-    sig { override.returns(T::Boolean) }
-    def downloaded? = downloadable.downloaded?
-
     sig { override.returns(Pathname) }
     def cached_download = downloadable.cached_download
 
+    sig { override.void }
+    def clear_cache = downloadable.clear_cache
+
+    sig { override.returns(T.nilable(Version)) }
+    def version = downloadable.version
+
+    sig { override.returns(T.class_of(AbstractDownloadStrategy)) }
+    def download_strategy = downloadable.download_strategy
+
+    sig { override.returns(AbstractDownloadStrategy) }
+    def downloader = downloadable.downloader
+
     sig {
       override.params(
         verify_download_integrity: T::Boolean,
@@ -68,5 +86,11 @@ module Homebrew
       downloadable.clear_cache
       retry
     end
+
+    sig { override.params(filename: Pathname).void }
+    def verify_download_integrity(filename) = downloadable.verify_download_integrity(filename)
+
+    sig { override.returns(String) }
+    def download_name = downloadable.download_name
   end
 end