Refactor formula, cask and Ruby source downloads to use shared code

Library/Homebrew/api.rb

@@ -14,6 +14,7 @@ module Homebrew
     extend Cachable
 
     HOMEBREW_CACHE_API = (HOMEBREW_CACHE/"api").freeze
+    HOMEBREW_CACHE_API_SOURCE = (HOMEBREW_CACHE/"api-source").freeze
 
     sig { params(endpoint: String).returns(Hash) }
     def self.fetch(endpoint)
@@ -114,50 +115,6 @@ module Homebrew
       end
     end
 
-    sig {
-      params(name: String, path: T.any(Pathname, String), git_head: String,
-             sha256: T.nilable(String)).returns(String)
-    }
-    def self.fetch_homebrew_cask_source(name, path:, git_head:, sha256: nil)
-      # TODO: unify with formula logic (https://github.com/Homebrew/brew/issues/14746)
-      raw_endpoint = "#{git_head}/#{path}"
-      return cache[raw_endpoint] if cache.present? && cache.key?(raw_endpoint)
-
-      # This API sometimes returns random 404s so needs a fallback at formulae.brew.sh.
-      raw_source_url = "https://raw.githubusercontent.com/Homebrew/homebrew-cask/#{raw_endpoint}"
-      api_source_url = "#{HOMEBREW_API_DEFAULT_DOMAIN}/cask-source/#{name}.rb"
-
-      url = raw_source_url
-      output = Utils::Curl.curl_output("--fail", url)
-
-      if !output.success? || output.blank?
-        url = api_source_url
-        output = Utils::Curl.curl_output("--fail", url)
-        if !output.success? || output.blank?
-          raise ArgumentError, <<~EOS
-            No valid file found at either of:
-            #{Tty.underline}#{raw_source_url}#{Tty.reset}
-            #{Tty.underline}#{api_source_url}#{Tty.reset}
-          EOS
-        end
-      end
-
-      cask_source = output.stdout
-      actual_sha256 = Digest::SHA256.hexdigest(cask_source)
-      if sha256 && actual_sha256 != sha256
-        raise ArgumentError, <<~EOS
-          SHA256 mismatch
-          Expected: #{Formatter.success(sha256.to_s)}
-            Actual: #{Formatter.error(actual_sha256.to_s)}
-               URL: #{url}
-          Check if you can access the URL in your browser.
-          Regardless, try again in a few minutes.
-        EOS
-      end
-
-      cache[raw_endpoint] = cask_source
-    end
-
     sig { params(json: Hash).returns(Hash) }
     def self.merge_variations(json)
       bottle_tag = ::Utils::Bottles::Tag.new(system: Homebrew::SimulateSystem.current_os,
@@ -207,5 +164,16 @@ module Homebrew
 
       [true, JSON.parse(json_data["payload"])]
     end
+
+    sig { params(path: Pathname).returns(T.nilable(Tap)) }
+    def self.tap_from_source_download(path)
+      source_relative_path = path.relative_path_from(Homebrew::API::HOMEBREW_CACHE_API_SOURCE)
+      return if source_relative_path.to_s.start_with?("../")
+
+      org, repo = source_relative_path.each_filename.first(2)
+      return if org.blank? || repo.blank?
+
+      Tap.fetch(org, repo)
+    end
   end
 end

Library/Homebrew/api/cask.rb

@@ -2,6 +2,7 @@
 # frozen_string_literal: true
 
 require "extend/cachable"
+require "api/download"
 
 module Homebrew
   module API
@@ -19,12 +20,25 @@ module Homebrew
           Homebrew::API.fetch "cask/#{token}.json"
         end
 
-        sig {
+        sig { params(cask: ::Cask::Cask).returns(::Cask::Cask) }
-          params(token: String, path: T.any(String, Pathname), git_head: String,
+        def source_download(cask)
-                 sha256: T.nilable(String)).returns(String)
+          path = cask.ruby_source_path.to_s || "Casks/#{cask.token}.rb"
-        }
+          sha256 = cask.ruby_source_checksum[:sha256]
-        def fetch_source(token, path:, git_head:, sha256: nil)
+          checksum = Checksum.new(sha256) if sha256
-          Homebrew::API.fetch_homebrew_cask_source token, path: path, git_head: git_head, sha256: sha256
+          git_head = cask.tap_git_head || "HEAD"
+          tap = cask.tap&.full_name || "Homebrew/homebrew-cask"
+
+          download = Homebrew::API::Download.new(
+            "https://raw.githubusercontent.com/#{tap}/#{git_head}/#{path}",
+            checksum,
+            mirrors: [
+              "#{HOMEBREW_API_DEFAULT_DOMAIN}/cask-source/#{File.basename(path)}",
+            ],
+            cache:   HOMEBREW_CACHE_API_SOURCE/"#{tap}/#{git_head}/Cask",
+          )
+          download.fetch
+          ::Cask::CaskLoader::FromPathLoader.new(download.symlink_location)
+                                            .load(config: cask.config)
         end
 
         sig { returns(T::Boolean) }

Library/Homebrew/api/download.rb

@@ -0,0 +1,45 @@
+# typed: true
+# frozen_string_literal: true
+
+require "downloadable"
+
+module Homebrew
+  module API
+    # @api private
+    class DownloadStrategy < CurlDownloadStrategy
+      sig { override.returns(Pathname) }
+      def symlink_location
+        cache/name
+      end
+    end
+
+    # @api private
+    class Download < Downloadable
+      sig {
+        params(
+          url:      String,
+          checksum: T.nilable(Checksum),
+          mirrors:  T::Array[String],
+          cache:    T.nilable(Pathname),
+        ).void
+      }
+      def initialize(url, checksum, mirrors: [], cache: nil)
+        super()
+        @url = URL.new(url, using: API::DownloadStrategy)
+        @checksum = checksum
+        @mirrors = mirrors
+        @cache = cache
+      end
+
+      sig { override.returns(Pathname) }
+      def cache
+        @cache || super
+      end
+
+      sig { returns(Pathname) }
+      def symlink_location
+        T.cast(downloader, API::DownloadStrategy).symlink_location
+      end
+    end
+  end
+end

Library/Homebrew/api/formula.rb

@@ -2,6 +2,7 @@
 # frozen_string_literal: true
 
 require "extend/cachable"
+require "api/download"
 
 module Homebrew
   module API
@@ -19,6 +20,24 @@ module Homebrew
           Homebrew::API.fetch "formula/#{name}.json"
         end
 
+        sig { params(formula: ::Formula).returns(::Formula) }
+        def source_download(formula)
+          path = formula.ruby_source_path || "Formula/#{formula.name}.rb"
+          git_head = formula.tap_git_head || "HEAD"
+          tap = formula.tap&.full_name || "Homebrew/homebrew-core"
+
+          download = Homebrew::API::Download.new(
+            "https://raw.githubusercontent.com/#{tap}/#{git_head}/#{path}",
+            formula.ruby_source_checksum,
+            cache: HOMEBREW_CACHE_API_SOURCE/"#{tap}/#{git_head}/Formula",
+          )
+          download.fetch
+          Formulary.factory(download.symlink_location,
+                            formula.active_spec_sym,
+                            alias_path: formula.alias_path,
+                            flags:      formula.class.build_flags)
+        end
+
         sig { returns(T::Boolean) }
         def download_and_cache_data!
           json_formulae, updated = Homebrew::API.fetch_json_api_file "formula.jws.json",

Library/Homebrew/cask/cask_loader.rb

@@ -21,10 +21,33 @@ module Cask
     end
 
     # Loads a cask from a string.
-    class FromContentLoader
+    class AbstractContentLoader
       include ILoader
-      attr_reader :content, :tap
+      extend T::Helpers
+      abstract!
 
+      sig { returns(String) }
+      attr_reader :content
+
+      sig { returns(T.nilable(Tap)) }
+      attr_reader :tap
+
+      private
+
+      sig {
+        overridable.params(
+          header_token: String,
+          options:      T.untyped,
+          block:        T.nilable(T.proc.bind(DSL).void),
+        ).returns(Cask)
+      }
+      def cask(header_token, **options, &block)
+        Cask.new(header_token, source: content, tap: tap, **options, config: @config, &block)
+      end
+    end
+
+    # Loads a cask from a string.
+    class FromContentLoader < AbstractContentLoader
       def self.can_load?(ref)
         return false unless ref.respond_to?(:to_str)
 
@@ -42,6 +65,8 @@ module Cask
       end
 
       def initialize(content, tap: nil)
+        super()
+
         @content = content.force_encoding("UTF-8")
         @tap = tap
       end
@@ -51,16 +76,10 @@ module Cask
 
         instance_eval(content, __FILE__, __LINE__)
       end
-
-      private
-
-      def cask(header_token, **options, &block)
-        Cask.new(header_token, source: content, tap: tap, **options, config: @config, &block)
-      end
     end
 
     # Loads a cask from a path.
-    class FromPathLoader < FromContentLoader
+    class FromPathLoader < AbstractContentLoader
       def self.can_load?(ref)
         path = Pathname(ref)
         %w[.rb .json].include?(path.extname) && path.expand_path.exist?
@@ -68,11 +87,15 @@ module Cask
 
       attr_reader :token, :path
 
-      def initialize(path) # rubocop:disable Lint/MissingSuper
+      def initialize(path, token: nil)
+        super()
+
         path = Pathname(path).expand_path
 
         @token = path.basename(path.extname).to_s
+
         @path = path
+        @tap = Homebrew::API.tap_from_source_download(path)
       end
 
       def load(config:)
@@ -153,8 +176,8 @@ module Cask
       end
 
       def initialize(path)
-        @tap = Tap.from_path(path)
         super(path)
+        @tap = Tap.from_path(path)
       end
     end
 
@@ -172,7 +195,7 @@ module Cask
       end
 
       def load(config:)
-        raise TapCaskUnavailableError.new(tap, token) unless tap.installed?
+        raise TapCaskUnavailableError.new(tap, token) unless T.must(tap).installed?
 
         super
       end
@@ -215,12 +238,12 @@ module Cask
         return false unless ref.is_a?(String)
         return false unless ref.match?(HOMEBREW_MAIN_TAP_CASK_REGEX)
 
-        token = ref.delete_prefix("homebrew/cask/")
+        token = ref.sub(%r{^homebrew/(?:homebrew-)?cask/}i, "")
         Homebrew::API::Cask.all_casks.key?(token)
       end
 
       def initialize(token, from_json: nil)
-        @token = token.delete_prefix("homebrew/cask/")
+        @token = token.sub(%r{^homebrew/(?:homebrew-)?cask/}i, "")
         @path = CaskLoader.default_path(token)
         @from_json = from_json
       end

Library/Homebrew/cask/download.rb

@@ -1,6 +1,7 @@
 # typed: true
 # frozen_string_literal: true
 
+require "downloadable"
 require "fileutils"
 require "cask/cache"
 require "cask/quarantine"
@@ -9,71 +10,75 @@ module Cask
   # A download corresponding to a {Cask}.
   #
   # @api private
-  class Download
+  class Download < ::Downloadable
     include Context
 
     attr_reader :cask
 
     def initialize(cask, quarantine: nil)
+      super()
+
       @cask = cask
       @quarantine = quarantine
     end
 
+    sig { override.returns(T.nilable(::URL)) }
+    def url
+      @url ||= ::URL.new(cask.url.to_s, cask.url.specs)
+    end
+
+    sig { override.returns(T.nilable(::Checksum)) }
+    def checksum
+      @checksum ||= cask.sha256 if cask.sha256 != :no_check
+    end
+
+    sig { override.returns(T.nilable(::Version)) }
+    def version
+      @version ||= ::Version.create(cask.version)
+    end
+
+    sig {
+      override
+        .params(quiet:                     T.nilable(T::Boolean),
+                verify_download_integrity: T::Boolean,
+                timeout:                   T.nilable(T.any(Integer, Float)))
+        .returns(Pathname)
+    }
     def fetch(quiet: nil, verify_download_integrity: true, timeout: nil)
-      downloaded_path = begin
       downloader.shutup! if quiet
-        downloader.fetch(timeout: timeout)
+
-        downloader.cached_location
+      begin
-      rescue => e
+        super(verify_download_integrity: false, timeout: timeout)
-        error = CaskError.new("Download failed on Cask '#{cask}' with message: #{e}")
+      rescue DownloadError => e
+        error = CaskError.new("Download failed on Cask '#{cask}' with message: #{e.cause}")
         error.set_backtrace e.backtrace
         raise error
       end
+
+      downloaded_path = cached_download
       quarantine(downloaded_path)
       self.verify_download_integrity(downloaded_path) if verify_download_integrity
       downloaded_path
     end
 
-    def downloader
-      @downloader ||= begin
-        strategy = DownloadStrategyDetector.detect(cask.url.to_s, cask.url.using)
-        strategy.new(cask.url.to_s, cask.token, cask.version, cache: Cache.path, **cask.url.specs)
-      end
-    end
-
     def time_file_size(timeout: nil)
-      downloader.resolved_time_file_size(timeout: timeout)
+      raise ArgumentError, "not supported for this download strategy" unless downloader.is_a?(CurlDownloadStrategy)
-    end
 
-    def clear_cache
+      T.cast(downloader, CurlDownloadStrategy).resolved_time_file_size(timeout: timeout)
-      downloader.clear_cache
-    end
-
-    def cached_download
-      downloader.cached_location
     end
 
     def basename
       downloader.basename
     end
 
+    sig { override.params(filename: Pathname).void }
     def verify_download_integrity(filename)
       if @cask.sha256 == :no_check
         opoo "No checksum defined for cask '#{@cask}', skipping verification."
         return
       end
 
-      begin
+      super
-        ohai "Verifying checksum for cask '#{@cask}'" if verbose?
-        filename.verify_checksum(@cask.sha256)
-      rescue ChecksumMissingError
-        opoo <<~EOS
-          Cannot verify integrity of '#{filename.basename}'.
-          No checksum was provided for this cask.
-          For your reference, the checksum is:
-            sha256 "#{filename.sha256}"
-        EOS
-      end
     end
 
     private
@@ -88,5 +93,20 @@ module Cask
         Quarantine.release!(download_path: path)
       end
     end
+
+    sig { override.returns(String) }
+    def download_name
+      cask.token
+    end
+
+    sig { override.returns(T.nilable(::URL)) }
+    def determine_url
+      url
+    end
+
+    sig { override.returns(Pathname) }
+    def cache
+      Cache.path
+    end
   end
 end

Library/Homebrew/cask/installer.rb

@@ -562,13 +562,7 @@ on_request: true)
     end
 
     def load_cask_from_source_api!
-      cask_source = Homebrew::API::Cask.fetch_source(
+      @cask = Homebrew::API::Cask.source_download(@cask)
-        @cask.token,
-        path:     @cask.ruby_source_path || "Casks/#{@cask.token}.rb",
-        git_head: @cask.tap_git_head,
-        sha256:   @cask.ruby_source_checksum["sha256"],
-      )
-      @cask = CaskLoader::FromContentLoader.new(cask_source, tap: @cask.tap).load(config: @cask.config)
     end
   end
 end

Library/Homebrew/cask/url.rb

@@ -1,10 +1,11 @@
 # typed: true
 # frozen_string_literal: true
 
-# Class corresponding to the `url` stanza.
+module Cask
-#
+  # Class corresponding to the `url` stanza.
-# @api private
+  #
-class URL < Delegator
+  # @api private
+  class URL < Delegator
     # @api private
     class DSL
       attr_reader :uri, :specs,
@@ -85,7 +86,7 @@ class URL < Delegator
       sig {
         params(
           uri:   T.nilable(T.any(URI::Generic, String)),
-        dsl:   T.nilable(Cask::DSL),
+          dsl:   T.nilable(::Cask::DSL),
           block: T.proc.params(arg0: T.all(String, PageWithURL)).returns(T.untyped),
         ).void
       }
@@ -154,7 +155,7 @@ class URL < Delegator
         data:            T.nilable(T::Hash[String, String]),
         only_path:       T.nilable(String),
         caller_location: Thread::Backtrace::Location,
-      dsl:             T.nilable(Cask::DSL),
+        dsl:             T.nilable(::Cask::DSL),
         block:           T.nilable(T.proc.params(arg0: T.all(String, BlockDSL::PageWithURL)).returns(T.untyped)),
       ).void
     }
@@ -243,4 +244,5 @@ class URL < Delegator
     def from_block?
       @from_block
     end
+  end
 end

Library/Homebrew/cask/url.rbi

@@ -1,5 +1,7 @@
 # typed: strict
 
-class URL
+module Cask
+  class URL
     include Kernel
+  end
 end

Library/Homebrew/cleanup.rb

@@ -51,11 +51,15 @@ module Homebrew
         pathname.mtime < days_ago && pathname.ctime < days_ago
       end
 
-      sig { params(pathname: Pathname, scrub: T::Boolean).returns(T::Boolean) }
+      sig { params(entry: { path: Pathname, type: T.nilable(Symbol) }, scrub: T::Boolean).returns(T::Boolean) }
-      def stale?(pathname, scrub: false)
+      def stale?(entry, scrub: false)
+        pathname = entry[:path]
         return false unless pathname.resolved_path.file?
 
-        if pathname.dirname.basename.to_s == "Cask"
+        case entry[:type]
+        when :api_source
+          stale_api_source?(pathname, scrub)
+        when :cask
           stale_cask?(pathname, scrub)
         else
           stale_formula?(pathname, scrub)
@@ -64,6 +68,31 @@ module Homebrew
 
       private
 
+      sig { params(pathname: Pathname, scrub: T::Boolean).returns(T::Boolean) }
+      def stale_api_source?(pathname, scrub)
+        return true if scrub
+
+        org, repo, git_head, type, basename = pathname.each_filename.to_a.last(5)
+
+        name = "#{org}/#{repo}/#{File.basename(T.must(basename), ".rb")}"
+        package = if type == "Cask"
+          begin
+            Cask::CaskLoader.load(name)
+          rescue Cask::CaskError
+            nil
+          end
+        else
+          begin
+            Formulary.factory(name)
+          rescue FormulaUnavailableError
+            nil
+          end
+        end
+        return true if package.nil?
+
+        package.tap_git_head != git_head
+      end
+
       sig { params(pathname: Pathname, scrub: T::Boolean).returns(T::Boolean) }
       def stale_formula?(pathname, scrub)
         return false unless HOMEBREW_CELLAR.directory?
@@ -235,6 +264,7 @@ module Homebrew
         Cleanup.autoremove(dry_run: dry_run?) if Homebrew::EnvConfig.autoremove?
 
         cleanup_cache
+        cleanup_empty_api_source_directories
         cleanup_logs
         cleanup_lockfiles
         cleanup_python_site_packages
@@ -287,14 +317,14 @@ module Homebrew
     def cleanup_formula(formula, quiet: false, ds_store: true, cache_db: true)
       formula.eligible_kegs_for_cleanup(quiet: quiet)
              .each(&method(:cleanup_keg))
-      cleanup_cache(Pathname.glob(cache/"#{formula.name}--*"))
+      cleanup_cache(Pathname.glob(cache/"#{formula.name}--*").map { |path| { path: path, type: nil } })
       rm_ds_store([formula.rack]) if ds_store
       cleanup_cache_db(formula.rack) if cache_db
       cleanup_lockfiles(FormulaLock.new(formula.name).path)
     end
 
     def cleanup_cask(cask, ds_store: true)
-      cleanup_cache(Pathname.glob(cache/"Cask/#{cask.token}--*"))
+      cleanup_cache(Pathname.glob(cache/"Cask/#{cask.token}--*").map { |path| { path: path, type: :cask } })
       rm_ds_store([cask.caskroom_path]) if ds_store
       cleanup_lockfiles(CaskLock.new(cask.token).path)
     end
@@ -316,16 +346,35 @@ module Homebrew
       end
     end
 
+    def cache_files
+      files = cache.directory? ? cache.children : []
+      cask_files = (cache/"Cask").directory? ? (cache/"Cask").children : []
+      api_source_files = (cache/"api-source").glob("*/*/*/*/*") # org/repo/git_head/type/file.rb
+
+      files.map { |path| { path: path, type: nil } } +
+        cask_files.map { |path| { path: path, type: :cask } } +
+        api_source_files.map { |path| { path: path, type: :api_source } }
+    end
+
+    def cleanup_empty_api_source_directories(directory = cache/"api-source")
+      return if dry_run?
+      return unless directory.directory?
+
+      directory.each_child do |child|
+        next unless child.directory?
+
+        cleanup_empty_api_source_directories(child)
+        child.rmdir if child.empty?
+      end
+    end
+
     def cleanup_unreferenced_downloads
       return if dry_run?
       return unless (cache/"downloads").directory?
 
       downloads = (cache/"downloads").children
 
-      referenced_downloads = [cache, cache/"Cask"].select(&:directory?)
+      referenced_downloads = cache_files.map { |file| file[:path] }.select(&:symlink?).map(&:resolved_path)
-                                                  .flat_map(&:children)
-                                                  .select(&:symlink?)
-                                                  .map(&:resolved_path)
 
       (downloads - referenced_downloads).each do |download|
         if self.class.incomplete?(download)
@@ -346,9 +395,10 @@ module Homebrew
     end
 
     def cleanup_cache(entries = nil)
-      entries ||= [cache, cache/"Cask"].select(&:directory?).flat_map(&:children)
+      entries ||= cache_files
 
-      entries.each do |path|
+      entries.each do |entry|
+        path = entry[:path]
         next if path == PERIODIC_CLEAN_FILE
 
         FileUtils.chmod_R 0755, path if self.class.go_cache_directory?(path) && !dry_run?
@@ -365,7 +415,7 @@ module Homebrew
         end
 
         # If we've specified --prune don't do the (expensive) .stale? check.
-        cleanup_path(path) { path.unlink } if !prune? && self.class.stale?(path, scrub: scrub?)
+        cleanup_path(path) { path.unlink } if !prune? && self.class.stale?(entry, scrub: scrub?)
       end
 
       cleanup_unreferenced_downloads

Library/Homebrew/dev-cmd/bump-formula-pr.rb

@@ -413,7 +413,7 @@ module Homebrew
     resource.url(url, specs)
     resource.owner = Resource.new(formula.name)
     forced_version = new_version && new_version != resource.version.to_s
-    resource.version = new_version if forced_version
+    resource.version(new_version) if forced_version
     odie "Couldn't identify version, specify it using `--version=`." if resource.version.blank?
     [resource.fetch, forced_version]
   end

Library/Homebrew/downloadable.rb

@@ -0,0 +1,133 @@
+# typed: true
+# frozen_string_literal: true
+
+require "url"
+require "checksum"
+
+# @api private
+class Downloadable
+  include Context
+  extend T::Helpers
+
+  abstract!
+
+  sig { returns(T.nilable(URL)) }
+  attr_reader :url
+
+  sig { returns(T.nilable(Checksum)) }
+  attr_reader :checksum
+
+  sig { returns(T::Array[String]) }
+  attr_reader :mirrors
+
+  sig { void }
+  def initialize
+    @mirrors = T.let([], T::Array[String])
+  end
+
+  def initialize_dup(other)
+    super
+    @checksum = @checksum.dup
+    @mirrors = @mirrors.dup
+    @version = @version.dup
+  end
+
+  sig { override.returns(T.self_type) }
+  def freeze
+    @checksum.freeze
+    @mirrors.freeze
+    @version.freeze
+    super
+  end
+
+  sig { returns(T::Boolean) }
+  def downloaded?
+    cached_download.exist?
+  end
+
+  sig { returns(Pathname) }
+  def cached_download
+    downloader.cached_location
+  end
+
+  sig { void }
+  def clear_cache
+    downloader.clear_cache
+  end
+
+  sig { returns(T.nilable(Version)) }
+  def version
+    return @version if @version && !@version.null?
+
+    version = determine_url&.version
+    version unless version&.null?
+  end
+
+  sig { returns(T.class_of(AbstractDownloadStrategy)) }
+  def download_strategy
+    @download_strategy ||= determine_url&.download_strategy
+  end
+
+  sig { returns(AbstractDownloadStrategy) }
+  def downloader
+    @downloader ||= begin
+      primary_url, *mirrors = determine_url_mirrors
+      raise ArgumentError, "attempted to use a Downloadable without a URL!" if primary_url.blank?
+
+      download_strategy.new(primary_url, download_name, version,
+                            mirrors: mirrors, cache: cache, **T.must(@url).specs)
+    end
+  end
+
+  sig { params(verify_download_integrity: T::Boolean, timeout: T.nilable(T.any(Integer, Float))).returns(Pathname) }
+  def fetch(verify_download_integrity: true, timeout: nil)
+    cache.mkpath
+
+    begin
+      downloader.fetch(timeout: timeout)
+    rescue ErrorDuringExecution, CurlDownloadStrategyError => e
+      raise DownloadError.new(self, e)
+    end
+
+    download = cached_download
+    verify_download_integrity(download) if verify_download_integrity
+    download
+  end
+
+  sig { params(filename: Pathname).void }
+  def verify_download_integrity(filename)
+    if filename.file?
+      ohai "Verifying checksum for '#{filename.basename}'" if verbose?
+      filename.verify_checksum(checksum)
+    end
+  rescue ChecksumMissingError
+    opoo <<~EOS
+      Cannot verify integrity of '#{filename.basename}'.
+      No checksum was provided.
+      For your reference, the checksum is:
+        sha256 "#{filename.sha256}"
+    EOS
+  end
+
+  private
+
+  sig { overridable.returns(String) }
+  def download_name
+    File.basename(determine_url.to_s)
+  end
+
+  sig { overridable.returns(T.nilable(URL)) }
+  def determine_url
+    @url
+  end
+
+  sig { overridable.returns(T::Array[String]) }
+  def determine_url_mirrors
+    [determine_url.to_s, *mirrors].uniq
+  end
+
+  sig { overridable.returns(Pathname) }
+  def cache
+    HOMEBREW_CACHE
+  end
+end

Library/Homebrew/exceptions.rb

@@ -603,13 +603,16 @@ class CompilerSelectionError < RuntimeError
   end
 end
 
-# Raised in {Resource#fetch}.
+# Raised in {Downloadable#fetch}.
 class DownloadError < RuntimeError
-  def initialize(resource, cause)
+  attr_reader :cause
+
+  def initialize(downloadable, cause)
     super <<~EOS
-      Failed to download resource #{resource.download_name.inspect}
+      Failed to download resource #{downloadable.download_name.inspect}
       #{cause.message}
     EOS
+    @cause = cause
     set_backtrace(cause.backtrace)
   end
 end

Library/Homebrew/formula.rb

@@ -181,7 +181,7 @@ class Formula
   attr_accessor :force_bottle
 
   # @private
-  def initialize(name, path, spec, alias_path: nil, force_bottle: false)
+  def initialize(name, path, spec, alias_path: nil, tap: nil, force_bottle: false)
     # Only allow instances of subclasses. The base class does not hold any spec information (URLs etc).
     raise "Do not call `Formula.new' directly without a subclass." unless self.class < Formula
 
@@ -191,7 +191,8 @@ class Formula
     self.class.freeze
 
     @name = name
-    @path = path
+    @unresolved_path = path
+    @path = path.resolved_path
     @alias_path = alias_path
     @alias_name = (File.basename(alias_path) if alias_path)
     @revision = self.class.revision || 0
@@ -199,7 +200,8 @@ class Formula
 
     @force_bottle = force_bottle
 
-    @tap = if path == Formulary.core_path(name)
+    @tap = tap
+    @tap ||= if path == Formulary.core_path(name)
       CoreTap.instance
     else
       Tap.from_path(path)
@@ -320,7 +322,7 @@ class Formula
   # The path that was specified to find this formula.
   def specified_path
     default_specified_path = Pathname(alias_path) if alias_path.present?
-    default_specified_path ||= path
+    default_specified_path ||= @unresolved_path
 
     return default_specified_path if default_specified_path.presence&.exist?
     return local_bottle_path if local_bottle_path.presence&.exist?
@@ -2094,6 +2096,18 @@ class Formula
     []
   end
 
+  # @private
+  sig { returns(T.nilable(String)) }
+  def ruby_source_path
+    path.relative_path_from(tap.path).to_s if tap && path.exist?
+  end
+
+  # @private
+  sig { returns(T.nilable(Checksum)) }
+  def ruby_source_checksum
+    Checksum.new(Digest::SHA256.file(path).hexdigest) if path.exist?
+  end
+
   # @private
   def to_hash
     dependencies = deps
@@ -2157,6 +2171,7 @@ class Formula
       "disable_reason"           => disable_reason,
       "service"                  => service&.serialize,
       "tap_git_head"             => tap_git_head,
+      "ruby_source_path"         => ruby_source_path,
       "ruby_source_checksum"     => {},
     }
 
@@ -2208,14 +2223,9 @@ class Formula
       }
     end
 
-    if self.class.loaded_from_api && active_spec.resource_defined?("ruby-source")
+    if (source_checksum = ruby_source_checksum)
       hsh["ruby_source_checksum"] = {
-        "sha256" => resource("ruby-source").checksum.hexdigest,
+        "sha256" => source_checksum.hexdigest,
-      }
-    elsif !self.class.loaded_from_api && path.exist?
-      hsh["ruby_source_path"] = (path.relative_path_from(tap.path).to_s if tap)
-      hsh["ruby_source_checksum"] = {
-        "sha256" => Digest::SHA256.file(path).hexdigest,
       }
     end
 

Library/Homebrew/formula_installer.rb

@@ -1191,16 +1191,7 @@ on_request: installed_on_request?, options: options)
     if pour_bottle?(output_warning: true)
       formula.fetch_bottle_tab
     else
-      if formula.class.loaded_from_api
+      @formula = Homebrew::API::Formula.source_download(formula) if formula.class.loaded_from_api
-        # TODO: unify with cask logic (https://github.com/Homebrew/brew/issues/14746)
-        resource = formula.resource("ruby-source")
-        resource.fetch
-        @formula = Formulary.factory(resource.cached_download,
-                                     formula.active_spec_sym,
-                                     alias_path: formula.alias_path,
-                                     flags:      formula.class.build_flags,
-                                     from:       :formula_installer)
-      end
 
       formula.fetch_patches
       formula.resources.each(&:fetch)

Library/Homebrew/formulary.rb

@@ -252,15 +252,6 @@ module Formulary
         link_overwrite overwrite_path
       end
 
-      resource "ruby-source" do
-        tap_git_head = json_formula.fetch("tap_git_head", "HEAD")
-        ruby_source_path = json_formula.fetch("ruby_source_path", "Formula/#{name}.rb")
-        ruby_source_sha256 = json_formula.dig("ruby_source_checksum", "sha256")
-
-        url "https://raw.githubusercontent.com/Homebrew/homebrew-core/#{tap_git_head}/#{ruby_source_path}"
-        sha256 ruby_source_sha256 if ruby_source_sha256
-      end
-
       def install
         raise "Cannot build from source from abstract formula."
       end
@@ -307,6 +298,17 @@ module Formulary
       def versioned_formulae_names
         self.class.instance_variable_get(:@versioned_formulae_array)
       end
+
+      @ruby_source_path_string = json_formula["ruby_source_path"]
+      def ruby_source_path
+        self.class.instance_variable_get(:@ruby_source_path_string)
+      end
+
+      @ruby_source_checksum_hash = json_formula["ruby_source_checksum"]
+      def ruby_source_checksum
+        checksum_hash = self.class.instance_variable_get(:@ruby_source_checksum_hash)
+        Checksum.new(checksum_hash["sha256"]) if checksum_hash&.key?("sha256")
+      end
     end
 
     T.cast(klass, T.class_of(Formula)).loaded_from_api = true
@@ -384,10 +386,13 @@ module Formulary
     attr_reader :path
     # The name used to install the formula
     attr_reader :alias_path
+    # The formula's tap (nil if it should be implicitly determined)
+    attr_reader :tap
 
-    def initialize(name, path)
+    def initialize(name, path, tap: nil)
       @name = name
-      @path = path.resolved_path
+      @path = path
+      @tap = tap
     end
 
     # Gets the formula instance.
@@ -396,7 +401,7 @@ module Formulary
     def get_formula(spec, alias_path: nil, force_bottle: false, flags: [], ignore_errors: false)
       alias_path ||= self.alias_path
       klass(flags: flags, ignore_errors: ignore_errors)
-        .new(name, path, spec, alias_path: alias_path, force_bottle: force_bottle)
+        .new(name, path, spec, alias_path: alias_path, tap: tap, force_bottle: force_bottle)
     end
 
     def klass(flags:, ignore_errors:)
@@ -473,12 +478,7 @@ module Formulary
     def initialize(path)
       path = Pathname.new(path).expand_path
       name = path.basename(".rb").to_s
-
+      super name, path, tap: Homebrew::API.tap_from_source_download(path)
-      # For files we've downloaded, they will be prefixed with `{URL MD5}--`.
-      # Remove that prefix to get the original filename.
-      name = name.split("--", 2).last if path.dirname == HOMEBREW_CACHE/"downloads"
-
-      super name, path
     end
   end
 
@@ -498,7 +498,6 @@ module Formulary
     end
 
     def load_file(flags:, ignore_errors:)
-      if @from != :formula_installer
       match = url.match(%r{githubusercontent.com/[\w-]+/[\w-]+/[a-f0-9]{40}(?:/Formula)?/(?<name>[\w+-.@]+).rb})
       if match
         raise UnsupportedInstallationMethod,
@@ -510,7 +509,6 @@ module Formulary
               "`brew extract` or `brew create` and `brew tap-new` to create a formula file in a tap " \
               "on GitHub instead."
       end
-      end
       HOMEBREW_CACHE_FORMULA.mkpath
       FileUtils.rm_f(path)
       curl_download url, to: path
@@ -525,30 +523,28 @@ module Formulary
 
   # Loads tapped formulae.
   class TapLoader < FormulaLoader
-    attr_reader :tap
-
     def initialize(tapped_name, from: nil)
       warn = [:keg, :rack].exclude?(from)
-      name, path = formula_name_path(tapped_name, warn: warn)
+      name, path, tap = formula_name_path(tapped_name, warn: warn)
-      super name, path
+      super name, path, tap: tap
     end
 
     def formula_name_path(tapped_name, warn: true)
       user, repo, name = tapped_name.split("/", 3).map(&:downcase)
-      @tap = Tap.fetch user, repo
+      tap = Tap.fetch user, repo
-      path = find_formula_from_name(name)
+      path = find_formula_from_name(name, tap)
 
       unless path.file?
-        if (possible_alias = @tap.alias_dir/name).file?
+        if (possible_alias = tap.alias_dir/name).file?
           path = possible_alias.resolved_path
           name = path.basename(".rb").to_s
-        elsif (new_name = @tap.formula_renames[name]) &&
+        elsif (new_name = tap.formula_renames[name]) &&
-              (new_path = find_formula_from_name(new_name)).file?
+              (new_path = find_formula_from_name(new_name, tap)).file?
           old_name = name
           path = new_path
           name = new_name
-          new_name = @tap.core_tap? ? name : "#{@tap}/#{name}"
+          new_name = tap.core_tap? ? name : "#{tap}/#{name}"
-        elsif (new_tap_name = @tap.tap_migrations[name])
+        elsif (new_tap_name = tap.tap_migrations[name])
           new_tap_user, new_tap_repo, = new_tap_name.split("/")
           new_tap_name = "#{new_tap_user}/#{new_tap_repo}"
           new_tap = Tap.fetch new_tap_name
@@ -562,7 +558,7 @@ module Formulary
         opoo "Use #{new_name} instead of deprecated #{old_name}" if warn && old_name && new_name
       end
 
-      [name, path]
+      [name, path, tap]
     end
 
     def get_formula(spec, alias_path: nil, force_bottle: false, flags: [], ignore_errors: false)
@@ -584,8 +580,8 @@ module Formulary
 
     private
 
-    def find_formula_from_name(name)
+    def find_formula_from_name(name, tap)
-      Formulary.find_formula_in_tap(name, @tap)
+      Formulary.find_formula_in_tap(name, tap)
     end
   end
 
@@ -768,7 +764,7 @@ module Formulary
     when URL_START_REGEX
       return FromUrlLoader.new(ref, from: from)
     when HOMEBREW_TAP_FORMULA_REGEX
-      if ref.start_with?("homebrew/core/") && !Homebrew::EnvConfig.no_install_from_api?
+      if ref.match?(%r{^homebrew/(?:homebrew-)?core/}i) && !Homebrew::EnvConfig.no_install_from_api?
         name = ref.split("/", 3).last
         return FormulaAPILoader.new(name) if Homebrew::API::Formula.all_formulae.key?(name)
         return AliasAPILoader.new(name) if Homebrew::API::Formula.all_aliases.key?(name)

Library/Homebrew/patch.rb

@@ -126,7 +126,7 @@ class ExternalPatch
 
   def owner=(owner)
     resource.owner = owner
-    resource.version = resource.checksum || ERB::Util.url_encode(resource.url)
+    resource.version(resource.checksum&.hexdigest || ERB::Util.url_encode(resource.url))
   end
 
   def apply

Library/Homebrew/resource.rb

@@ -1,9 +1,7 @@
 # typed: true
 # frozen_string_literal: true
 
-require "download_strategy"
+require "downloadable"
-require "checksum"
-require "version"
 require "mktemp"
 require "livecheck"
 require "extend/on_system"
@@ -13,14 +11,13 @@ require "extend/on_system"
 # of this class.
 #
 # @api private
-class Resource
+class Resource < Downloadable
-  include Context
   include FileUtils
   include OnSystem::MacOSAndLinux
 
-  attr_reader :mirrors, :specs, :using, :source_modified_time, :patches, :owner
+  attr_reader :source_modified_time, :patches, :owner
-  attr_writer :version
+  attr_writer :checksum
-  attr_accessor :download_strategy, :checksum
+  attr_accessor :download_strategy
 
   # Formula name must be set after the DSL, as we have no access to the
   # formula name before initialization of the formula.
@@ -28,39 +25,25 @@ class Resource
 
   sig { params(name: T.nilable(String), block: T.nilable(T.proc.bind(Resource).void)).void }
   def initialize(name = nil, &block)
+    super()
     # Ensure this is synced with `initialize_dup` and `freeze` (excluding simple objects like integers and booleans)
     @name = name
-    @url = nil
-    @version = nil
-    @mirrors = []
-    @specs = {}
-    @checksum = nil
-    @using = nil
     @patches = []
     @livecheck = Livecheck.new(self)
     @livecheckable = false
+    @insecure = false
     instance_eval(&block) if block
   end
 
   def initialize_dup(other)
     super
     @name = @name.dup
-    @version = @version.dup
-    @mirrors = @mirrors.dup
-    @specs = @specs.dup
-    @checksum = @checksum.dup
-    @using = @using.dup
     @patches = @patches.dup
     @livecheck = @livecheck.dup
   end
 
   def freeze
     @name.freeze
-    @version.freeze
-    @mirrors.freeze
-    @specs.freeze
-    @checksum.freeze
-    @using.freeze
     @patches.freeze
     @livecheck.freeze
     super
@@ -73,15 +56,15 @@ class Resource
     return if !owner.respond_to?(:full_name) || owner.full_name != "ca-certificates"
     return if Homebrew::EnvConfig.no_insecure_redirect?
 
-    @specs[:insecure] = !specs[:bottle] && !DevelopmentTools.ca_file_handles_most_https_certificates?
+    @insecure = !specs[:bottle] && !DevelopmentTools.ca_file_handles_most_https_certificates?
+    return if @url.nil?
+
+    specs = if @insecure
+      @url.specs.merge({ insecure: true })
+    else
+      @url.specs.except(:insecure)
     end
-
+    @url = URL.new(@url.to_s, specs)
-  def downloader
-    return @downloader if @downloader.present?
-
-    url, *mirrors = determine_url_mirrors
-    @downloader = download_strategy.new(url, download_name, version,
-                                        mirrors: mirrors, **specs)
   end
 
   # Removes /s from resource names; this allows Go package names
@@ -98,18 +81,6 @@ class Resource
     "#{owner.name}--#{escaped_name}"
   end
 
-  def downloaded?
-    cached_download.exist?
-  end
-
-  def cached_download
-    downloader.cached_location
-  end
-
-  def clear_cache
-    downloader.clear_cache
-  end
-
   # Verifies download and unpacks it.
   # The block may call `|resource, staging| staging.retain!` to retain the staging
   # directory. Subclasses that override stage should implement the tmp
@@ -171,33 +142,9 @@ class Resource
   end
 
   def fetch(verify_download_integrity: true)
-    HOMEBREW_CACHE.mkpath
-
     fetch_patches
 
-    begin
+    super(verify_download_integrity: verify_download_integrity)
-      downloader.fetch
-    rescue ErrorDuringExecution, CurlDownloadStrategyError => e
-      raise DownloadError.new(self, e)
-    end
-
-    download = cached_download
-    verify_download_integrity(download) if verify_download_integrity
-    download
-  end
-
-  def verify_download_integrity(filename)
-    if filename.file?
-      ohai "Verifying checksum for '#{filename.basename}'" if verbose?
-      filename.verify_checksum(checksum)
-    end
-  rescue ChecksumMissingError
-    opoo <<~EOS
-      Cannot verify integrity of '#{filename.basename}'.
-      No checksum was provided for this resource.
-      For your reference, the checksum is:
-        sha256 "#{filename.sha256}"
-    EOS
   end
 
   # @!attribute [w] livecheck
@@ -230,24 +177,29 @@ class Resource
   end
 
   def url(val = nil, **specs)
-    return @url if val.nil?
+    return @url&.to_s if val.nil?
 
     specs = specs.dup
     # Don't allow this to be set.
     specs.delete(:insecure)
 
-    @url = val
+    specs[:insecure] = true if @insecure
-    @using = specs.delete(:using)
+
-    @download_strategy = DownloadStrategyDetector.detect(url, using)
+    @url = URL.new(val, specs)
-    @specs.merge!(specs)
     @downloader = nil
-    @version = detect_version(@version)
+    @download_strategy = @url.download_strategy
   end
 
   def version(val = nil)
-    return @version if val.nil?
+    return super() if val.nil?
 
-    @version = detect_version(val)
+    @version = case val
+    when String  then Version.create(val)
+    when Version then val
+    else
+      # TODO: This can probably go if/when typechecking is enforced in taps.
+      raise TypeError, "version '#{val.inspect}' should be a string"
+    end
   end
 
   def mirror(val)
@@ -259,6 +211,14 @@ class Resource
     patches << p
   end
 
+  def using
+    @url&.using
+  end
+
+  def specs
+    @url&.specs || {}.freeze
+  end
+
   protected
 
   def stage_resource(prefix, debug_symbols: false, &block)
@@ -267,18 +227,6 @@ class Resource
 
   private
 
-  def detect_version(val)
-    version = case val
-    when nil     then url.nil? ? Version::NULL : Version.detect(url, **specs)
-    when String  then Version.create(val)
-    when Version then val
-    else
-      raise TypeError, "version '#{val.inspect}' should be a string"
-    end
-
-    version unless version.null?
-  end
-
   def determine_url_mirrors
     extra_urls = []
 
@@ -301,7 +249,7 @@ class Resource
       end
     end
 
-    [*extra_urls, url, *mirrors].uniq
+    [*extra_urls, *super].uniq
   end
 
   # A resource containing a Go package.

Library/Homebrew/software_spec.rb

@@ -89,15 +89,11 @@ class SoftwareSpec
     @resource.owner = self
     resources.each_value do |r|
       r.owner = self
-      r.version ||= begin
+      next if r.version
+
       raise "#{full_name}: version missing for \"#{r.name}\" resource!" if version.nil?
 
-        if version.head?
+      r.version(version.head? ? Version.create("HEAD") : version.dup)
-          Version.create("HEAD")
-        else
-          version.dup
-        end
-      end
     end
     patches.each { |p| p.owner = self }
   end
@@ -281,7 +277,7 @@ end
 class HeadSoftwareSpec < SoftwareSpec
   def initialize(flags: [])
     super
-    @resource.version = Version.create("HEAD")
+    @resource.version(Version.create("HEAD"))
   end
 
   def verify_download_integrity(_filename)
@@ -340,7 +336,6 @@ class Bottle
   def initialize(formula, spec, tag = nil)
     @name = formula.name
     @resource = Resource.new
-    @resource.specs[:bottle] = true
     @resource.owner = formula
     @spec = spec
 
@@ -350,7 +345,7 @@ class Bottle
     @cellar = tag_spec.cellar
     @rebuild = spec.rebuild
 
-    @resource.version = formula.pkg_version.to_s
+    @resource.version(formula.pkg_version.to_s)
     @resource.checksum = tag_spec.checksum
 
     @fetch_tab_retried = false
@@ -468,13 +463,15 @@ class Bottle
         using:   CurlGitHubPackagesDownloadStrategy,
         headers: ["Accept: application/vnd.oci.image.index.v1+json"],
       )
-      resource.downloader.resolved_basename = "#{name}-#{version_rebuild}.bottle_manifest.json"
+      T.cast(resource.downloader, CurlGitHubPackagesDownloadStrategy).resolved_basename =
+        "#{name}-#{version_rebuild}.bottle_manifest.json"
       resource
     end
   end
 
   def select_download_strategy(specs)
     specs[:using] ||= DownloadStrategyDetector.detect(@root_url)
+    specs[:bottle] = true
     specs
   end
 

Library/Homebrew/tap_constants.rb

@@ -6,11 +6,12 @@ HOMEBREW_TAP_FORMULA_REGEX = %r{^([\w-]+)/([\w-]+)/([\w+-.@]+)$}.freeze
 # Match taps' casks, e.g. `someuser/sometap/somecask`
 HOMEBREW_TAP_CASK_REGEX = %r{^([\w-]+)/([\w-]+)/([a-z0-9\-_]+)$}.freeze
 # Match main cask taps' casks, e.g. `homebrew/cask/somecask` or `somecask`
-HOMEBREW_MAIN_TAP_CASK_REGEX = %r{^(homebrew/cask/)?[a-z0-9\-_]+$}.freeze
+HOMEBREW_MAIN_TAP_CASK_REGEX = %r{^([Hh]omebrew/(?:homebrew-)?cask/)?[a-z0-9\-_]+$}.freeze
 # Match taps' directory paths, e.g. `HOMEBREW_LIBRARY/Taps/someuser/sometap`
 HOMEBREW_TAP_DIR_REGEX = %r{#{Regexp.escape(HOMEBREW_LIBRARY.to_s)}/Taps/(?<user>[\w-]+)/(?<repo>[\w-]+)}.freeze
 # Match taps' formula paths, e.g. `HOMEBREW_LIBRARY/Taps/someuser/sometap/someformula`
 HOMEBREW_TAP_PATH_REGEX = Regexp.new(HOMEBREW_TAP_DIR_REGEX.source + %r{(?:/.*)?$}.source).freeze
 # Match official taps' casks, e.g. `homebrew/cask/somecask or homebrew/cask-versions/somecask`
-HOMEBREW_CASK_TAP_CASK_REGEX = %r{^(?:([Cc]askroom)/(cask|versions)|(homebrew)/(cask|cask-[\w-]+))/([\w+-.]+)$}.freeze
+HOMEBREW_CASK_TAP_CASK_REGEX =
+  %r{^(?:([Cc]askroom)/(cask|versions)|([Hh]omebrew)/(?:homebrew-)?(cask|cask-[\w-]+))/([\w+-.]+)$}.freeze
 HOMEBREW_OFFICIAL_REPO_PREFIXES_REGEX = /^(home|linux)brew-/.freeze

Library/Homebrew/test/api/cask_spec.rb

@@ -45,14 +45,4 @@ describe Homebrew::API::Cask do
       expect(casks_output).to eq casks_hash
     end
   end
-
-  describe "::fetch_source" do
-    it "fetches the source of a cask (defaulting to master when no `git_head` is passed)" do
-      curl_output = instance_double(SystemCommand::Result, stdout: "foo", success?: true)
-      expect(Utils::Curl).to receive(:curl_output)
-        .with("--fail", "https://raw.githubusercontent.com/Homebrew/homebrew-cask/HEAD/Casks/foo.rb")
-        .and_return(curl_output)
-      described_class.fetch_source("foo", path: "Casks/foo.rb", git_head: "HEAD")
-    end
-  end
 end

Library/Homebrew/test/api_spec.rb

@@ -67,19 +67,4 @@ describe Homebrew::API do
       end.to raise_error(SystemExit)
     end
   end
-
-  describe "::fetch_file_source" do
-    it "fetches a file" do
-      mock_curl_output stdout: json
-      fetched_json = described_class.fetch_homebrew_cask_source("foo", path: "Casks/foo.rb", git_head: "HEAD")
-      expect(fetched_json).to eq json
-    end
-
-    it "raises an error if the file does not exist" do
-      mock_curl_output success: false
-      expect do
-        described_class.fetch_homebrew_cask_source("bar", path: "Casks/bar.rb", git_head: "HEAD")
-      end.to raise_error(ArgumentError, /No valid file found/)
-    end
-  end
 end

Library/Homebrew/test/cask/cask_spec.rb

@@ -231,7 +231,7 @@ describe Cask::Cask, :cask do
 
     context "when loaded from json file" do
       it "returns expected hash" do
-        expect(Homebrew::API::Cask).not_to receive(:fetch_source)
+        expect(Homebrew::API::Cask).not_to receive(:source_download)
         hash = Cask::CaskLoader::FromAPILoader.new(
           "everything", from_json: JSON.parse(expected_json)
         ).load(config: nil).to_h

Library/Homebrew/test/cask/download_spec.rb

@@ -12,6 +12,7 @@ module Cask
       let(:downloaded_path) { Pathname.new("cask.zip") }
 
       before do
+        allow(downloaded_path).to receive(:file?).and_return(true)
         allow(downloaded_path).to receive(:sha256).and_return(computed_sha256)
       end
 

Library/Homebrew/test/cask/installer_spec.rb

@@ -240,7 +240,8 @@ describe Cask::Installer, :cask do
       let(:content) { File.read(path) }
 
       it "installs cask" do
-        expect(Homebrew::API::Cask).to receive(:fetch_source).once.and_return(content)
+        source_caffeine = Cask::CaskLoader.load(path)
+        expect(Homebrew::API::Cask).to receive(:source_download).once.and_return(source_caffeine)
 
         caffeine = Cask::CaskLoader.load(path)
         expect(caffeine).to receive(:loaded_from_api?).once.and_return(true)
@@ -307,7 +308,8 @@ describe Cask::Installer, :cask do
       end
 
       it "uninstalls cask" do
-        expect(Homebrew::API::Cask).to receive(:fetch_source).twice.and_return(content)
+        source_caffeine = Cask::CaskLoader.load(path)
+        expect(Homebrew::API::Cask).to receive(:source_download).twice.and_return(source_caffeine)
 
         caffeine = Cask::CaskLoader.load(path)
         expect(caffeine).to receive(:loaded_from_api?).twice.and_return(true)

Library/Homebrew/test/formula_spec.rb

@@ -206,14 +206,14 @@ describe Formula do
   example "installed alias with tap" do
     tap = Tap.new("user", "repo")
     name = "foo"
-    path = "#{tap.path}/Formula/#{name}.rb"
+    path = tap.path/"Formula/#{name}.rb"
     f = formula name, path: path do
       url "foo-1.0"
     end
 
     build_values_with_no_installed_alias = [
       BuildOptions.new(Options.new, f.options),
-      Tab.new(source: { "path" => f.path }),
+      Tab.new(source: { "path" => f.path.to_s }),
     ]
     build_values_with_no_installed_alias.each do |build|
       f.build = build

Library/Homebrew/test/formulary_spec.rb

@@ -15,7 +15,7 @@ describe Formulary do
 
         bottle do
           root_url "file://#{bottle_dir}"
-          sha256 cellar: :any_skip_relocation, #{Utils::Bottles.tag}: "8f9aecd233463da6a4ea55f5f88fc5841718c013f3e2a7941350d6130f1dc149"
+          sha256 cellar: :any_skip_relocation, #{Utils::Bottles.tag}: "d7b9f4e8bf83608b71fe958a99f19f2e5e68bb2582965d32e41759c24f1aef97"
         end
 
         def install
@@ -243,7 +243,7 @@ describe Formulary do
                   Utils::Bottles.tag.to_s => {
                     "cellar" => ":any",
                     "url"    => "file://#{bottle_dir}/#{formula_name}",
-                    "sha256" => "8f9aecd233463da6a4ea55f5f88fc5841718c013f3e2a7941350d6130f1dc149",
+                    "sha256" => "d7b9f4e8bf83608b71fe958a99f19f2e5e68bb2582965d32e41759c24f1aef97",
                   },
                 },
               },

Library/Homebrew/test/resource_spec.rb

@@ -143,7 +143,7 @@ describe Resource do
 
   describe "#download_strategy" do
     it "returns the download strategy" do
-      strategy = Object.new
+      strategy = Class.new(AbstractDownloadStrategy)
       expect(DownloadStrategyDetector)
         .to receive(:detect).with("foo", nil).and_return(strategy)
       resource.url("foo")

Library/Homebrew/test/support/fixtures/failball.rb

@@ -3,7 +3,7 @@
 
 class Failball < Formula
   def initialize(name = "failball", path = Pathname.new(__FILE__).expand_path, spec = :stable,
-                 alias_path: nil, force_bottle: false)
+                 alias_path: nil, tap: nil, force_bottle: false)
     super
   end
 

Library/Homebrew/test/support/fixtures/testball.rb

@@ -3,7 +3,7 @@
 
 class Testball < Formula
   def initialize(name = "testball", path = Pathname.new(__FILE__).expand_path, spec = :stable,
-                 alias_path: nil, force_bottle: false)
+                 alias_path: nil, tap: nil, force_bottle: false)
     super
   end
 

Library/Homebrew/test/support/fixtures/testball_bottle.rb

@@ -3,7 +3,7 @@
 
 class TestballBottle < Formula
   def initialize(name = "testball_bottle", path = Pathname.new(__FILE__).expand_path, spec = :stable,
-                 alias_path: nil, force_bottle: false)
+                 alias_path: nil, tap: nil, force_bottle: false)
     super
   end
 
@@ -13,7 +13,7 @@ class TestballBottle < Formula
 
     bottle do
       root_url "file://#{TEST_FIXTURE_DIR}/bottles"
-      sha256 cellar: :any_skip_relocation, Utils::Bottles.tag.to_sym => "8f9aecd233463da6a4ea55f5f88fc5841718c013f3e2a7941350d6130f1dc149"
+      sha256 cellar: :any_skip_relocation, Utils::Bottles.tag.to_sym => "d7b9f4e8bf83608b71fe958a99f19f2e5e68bb2582965d32e41759c24f1aef97"
     end
 
     cxxstdlib_check :skip

Library/Homebrew/test/support/fixtures/testball_bottle_cellar.rb

@@ -3,7 +3,7 @@
 
 class TestballBottleCellar < Formula
   def initialize(name = "testball_bottle", path = Pathname.new(__FILE__).expand_path, spec = :stable,
-                 alias_path: nil, force_bottle: false)
+                 alias_path: nil, tap: nil, force_bottle: false)
     super
   end
 
@@ -13,7 +13,7 @@ class TestballBottleCellar < Formula
 
     bottle do
       root_url "file://#{TEST_FIXTURE_DIR}/bottles"
-      sha256 cellar: :any_skip_relocation, Utils::Bottles.tag.to_sym => "8f9aecd233463da6a4ea55f5f88fc5841718c013f3e2a7941350d6130f1dc149"
+      sha256 cellar: :any_skip_relocation, Utils::Bottles.tag.to_sym => "d7b9f4e8bf83608b71fe958a99f19f2e5e68bb2582965d32e41759c24f1aef97"
     end
 
     cxxstdlib_check :skip

Library/Homebrew/url.rb

@@ -0,0 +1,33 @@
+# typed: true
+# frozen_string_literal: true
+
+require "download_strategy"
+require "version"
+
+# @api private
+class URL
+  attr_reader :specs, :using
+
+  sig { params(url: String, specs: T::Hash[Symbol, T.untyped]).void }
+  def initialize(url, specs = {})
+    @url = url.freeze
+    @specs = specs.dup
+    @using = @specs.delete(:using)
+    @specs.freeze
+  end
+
+  sig { returns(String) }
+  def to_s
+    @url
+  end
+
+  sig { returns(T.class_of(AbstractDownloadStrategy)) }
+  def download_strategy
+    @download_strategy ||= DownloadStrategyDetector.detect(@url, @using)
+  end
+
+  sig { returns(Version) }
+  def version
+    @version ||= Version.detect(@url, **@specs)
+  end
+end