Add Formula#loaded_from_api?.

Library/Homebrew/formula.rb

@@ -427,6 +427,12 @@ def bottle_for_tag(tag = nil)
   # @see .version
   delegate version: :active_spec
 
+  # Whether this formula was loaded using the formulae.brew.sh API
+  # @!method loaded_from_api?
+  # @private
+  # @see .loaded_from_api?
+  delegate loaded_from_api?: :"self.class"
+
   def update_head_version
     return unless head?
     return unless head.downloader.is_a?(VCSDownloadStrategy)
@@ -2238,7 +2244,7 @@ def to_hash_with_variations
     hash = to_hash
 
     # Take from API, merging in local install status.
-    if self.class.loaded_from_api && !Homebrew::EnvConfig.no_install_from_api?
+    if loaded_from_api? && !Homebrew::EnvConfig.no_install_from_api?
       json_formula = Homebrew::API::Formula.all_formulae[name].dup
       return json_formula.merge(
         hash.slice("name", "installed", "linked_keg", "pinned", "outdated"),
@@ -2758,6 +2764,7 @@ def inherited(child)
         @skip_clean_paths = Set.new
         @link_overwrite_paths = Set.new
         @allowed_missing_libraries = Set.new
+        @loaded_from_api = false
       end
     end
 
@@ -2784,7 +2791,7 @@ def freeze
 
     # Whether this formula was loaded using the formulae.brew.sh API
     # @private
-    attr_accessor :loaded_from_api
+    attr_predicate :loaded_from_api?
 
     # Whether this formula contains OS/arch-specific blocks
     # (e.g. `on_macos`, `on_arm`, `on_monterey :or_older`, `on_system :linux, macos: :big_sur_or_newer`).

Library/Homebrew/formula.rbi

@@ -3,6 +3,8 @@
 # This file provides definitions for Forwardable#delegate, which is currently not supported by Sorbet.
 
 class Formula
+  sig { returns(T::Boolean) }
+  def loaded_from_api?; end
   def bottle_defined?; end
   def bottle_tag?(tag = nil); end
   def bottled?(tag = nil); end

Library/Homebrew/formula_installer.rb

@@ -1191,7 +1191,7 @@ def fetch
     if pour_bottle?(output_warning: true)
       formula.fetch_bottle_tab
     else
-      @formula = Homebrew::API::Formula.source_download(formula) if formula.class.loaded_from_api
+      @formula = Homebrew::API::Formula.source_download(formula) if formula.loaded_from_api?
 
       formula.fetch_patches
       formula.resources.each(&:fetch)
@@ -1227,7 +1227,7 @@ def pour
     tab.unused_options = []
     tab.built_as_bottle = true
     tab.poured_from_bottle = true
-    tab.loaded_from_api = formula.class.loaded_from_api
+    tab.loaded_from_api = formula.loaded_from_api?
     tab.installed_as_dependency = installed_as_dependency?
     tab.installed_on_request = installed_on_request?
     tab.time = Time.now.to_i

Library/Homebrew/formulary.rb

@@ -136,7 +136,7 @@ def self.load_formula_from_api(name, flags:)
 
     mod.const_set(:BUILD_FLAGS, flags)
 
-    class_s = Formulary.class_s(name)
+    class_name = class_s(name)
     json_formula = Homebrew::API::Formula.all_formulae[name]
     json_formula = Homebrew::API.merge_variations(json_formula)
 
@@ -147,6 +147,8 @@ def self.load_formula_from_api(name, flags:)
     end
 
     klass = Class.new(::Formula) do
+      @loaded_from_api = true
+
       desc json_formula["desc"]
       homepage json_formula["homepage"]
       license SPDX.string_to_license_expression(json_formula["license"])
@@ -311,8 +313,7 @@ def ruby_source_checksum
       end
     end
 
-    T.cast(klass, T.class_of(Formula)).loaded_from_api = true
-    mod.const_set(class_s, klass)
+    mod.const_set(class_name, klass)
 
     cache[:api] ||= {}
     cache[:api][name] = klass