Merge pull request #16713 from reitermarkus/tap-formula-files

Support `Tap#formula_files` when using API.

Library/Homebrew/cmd/readall.rb

@@ -38,6 +38,7 @@ module Homebrew
   def readall
     args = readall_args.parse
 
+    Homebrew.with_no_api_env do
       if args.syntax? && args.no_named?
         scan_files = "#{HOMEBREW_LIBRARY_PATH}/**/*.rb"
         ruby_files = Dir.glob(scan_files).grep_v(%r{/(vendor)/})
@@ -56,7 +57,7 @@ module Homebrew
           raise UsageError, "`brew readall` needs a tap or `--eval-all` passed or `HOMEBREW_EVAL_ALL` set!"
         end
 
-      Tap
+        Tap.select(&:installed?)
       else
         args.named.to_installed_taps
       end
@@ -66,3 +67,4 @@ module Homebrew
       end
     end
   end
+end

Library/Homebrew/tap.rb

@@ -1146,9 +1146,9 @@ class CoreTap < AbstractCoreTap
   # @private
   sig { returns(T::Array[Pathname]) }
   def formula_files
-    return super if Homebrew::EnvConfig.no_install_from_api? || installed?
+    return super if Homebrew::EnvConfig.no_install_from_api?
 
-    raise TapUnavailableError, name
+    formula_files_by_name.values
   end
 
   # @private