Use API for description searches

Both `brew search --desc` and `brew desc --search` use API for cask and
formula searches unless `--eval-all` or `HOMEBREW_EVAL_ALL` set.
Description searches do not use the description cache or eval any
formulas/casks.

With `--eval-all`, description search reverts to the old behavior.

Library/Homebrew/cmd/desc.rb

@@ -47,10 +47,6 @@ def run
         end
 
         if search_type.present?
-          if !args.eval_all? && !Homebrew::EnvConfig.eval_all?
-            raise UsageError, "`brew desc --search` needs `--eval-all` passed or `HOMEBREW_EVAL_ALL` set!"
-          end
-
           query = args.named.join(" ")
           string_or_regex = Search.query_regexp(query)
           return Search.search_descriptions(string_or_regex, args, search_type:)

Library/Homebrew/cmd/search.rb

@@ -70,10 +70,6 @@ def run
         string_or_regex = Search.query_regexp(query)
 
         if args.desc?
-          if !args.eval_all? && !Homebrew::EnvConfig.eval_all?
-            raise UsageError, "`brew search --desc` needs `--eval-all` passed or `HOMEBREW_EVAL_ALL` set!"
-          end
-
           Search.search_descriptions(string_or_regex, args)
         elsif args.pull_request?
           search_pull_requests(query)

Library/Homebrew/descriptions.rb

@@ -9,7 +9,8 @@
 class Descriptions
   # Given a regex, find all formulae whose specified fields contain a match.
   def self.search(string_or_regex, field, cache_store, eval_all = Homebrew::EnvConfig.eval_all?)
-    cache_store.populate_if_empty!(eval_all:)
+    # allow searching a simple hash, not only cache_store objects
+    cache_store.populate_if_empty!(eval_all:) if cache_store.methods.include?(:populate_if_empty!)
 
     results = case field
     when :name

Library/Homebrew/search.rb

@@ -22,19 +22,29 @@ def self.search_descriptions(string_or_regex, args, search_type: :desc)
 
       if args.formula? || both
         ohai "Formulae"
-        CacheStoreDatabase.use(:descriptions) do |db|
-          cache_store = DescriptionCacheStore.new(db)
-          Descriptions.search(string_or_regex, search_type, cache_store, eval_all).print
+        if eval_all
+          CacheStoreDatabase.use(:descriptions) do |db|
+            cache_store = DescriptionCacheStore.new(db)
+            Descriptions.search(string_or_regex, search_type, cache_store, eval_all).print
+          end
+        else
+          descriptions = Homebrew::API::Formula.all_formulae.transform_values { |data| data["desc"] }
+          Descriptions.search(string_or_regex, search_type, descriptions, eval_all).print
         end
       end
       return if !args.cask? && !both
 
       puts if both
 
       ohai "Casks"
-      CacheStoreDatabase.use(:cask_descriptions) do |db|
-        cache_store = CaskDescriptionCacheStore.new(db)
-        Descriptions.search(string_or_regex, search_type, cache_store, eval_all).print
+      if eval_all
+        CacheStoreDatabase.use(:cask_descriptions) do |db|
+          cache_store = CaskDescriptionCacheStore.new(db)
+          Descriptions.search(string_or_regex, search_type, cache_store, eval_all).print
+        end
+      else
+        descriptions = Homebrew::API::Cask.all_casks.transform_values { |data| data["desc"] }
+        Descriptions.search(string_or_regex, search_type, descriptions, eval_all).print
       end
     end