diff --git a/Library/Homebrew/cli/named_args.rb b/Library/Homebrew/cli/named_args.rb
index 1c90f6032f..34b9b04049 100644
--- a/Library/Homebrew/cli/named_args.rb
+++ b/Library/Homebrew/cli/named_args.rb
@@ -188,6 +188,18 @@ module Homebrew
           .map(&:freeze).freeze
       end
 
+      sig { returns(T::Array[Tap]) }
+      def to_taps
+        @to_taps ||= downcased_unique_named.map { |name| Tap.fetch name }.uniq.freeze
+      end
+
+      sig { returns(T::Array[Tap]) }
+      def to_installed_taps
+        @to_installed_taps ||= to_taps.each do |tap|
+          raise TapUnavailableError, tap.name unless tap.installed?
+        end.uniq.freeze
+      end
+
       sig { returns(T::Array[String]) }
       def homebrew_tap_cask_names
         downcased_unique_named.grep(HOMEBREW_CASK_TAP_CASK_REGEX)
diff --git a/Library/Homebrew/cli/parser.rb b/Library/Homebrew/cli/parser.rb
index 3b635e7e5b..d2454f0bc5 100644
--- a/Library/Homebrew/cli/parser.rb
+++ b/Library/Homebrew/cli/parser.rb
@@ -126,9 +126,9 @@ module Homebrew
         @conflicts = []
         @switch_sources = {}
         @processed_options = []
+        @named_args_type = nil
         @max_named_args = nil
         @min_named_args = nil
-        @min_named_type = nil
         @hide_from_man_page = false
         @formula_options = false
 
@@ -355,33 +355,71 @@ module Homebrew
         @formula_options = true
       end
 
+      sig do
+        params(
+          type:   T.any(Symbol, T::Array[String], T::Array[Symbol]),
+          number: T.nilable(Integer),
+          min:    T.nilable(Integer),
+          max:    T.nilable(Integer),
+        ).void
+      end
+      def named_args(type = nil, number: nil, min: nil, max: nil)
+        if number.present? && (min.present? || max.present?)
+          raise ArgumentError, "Do not specify both `number` and `min` or `max`"
+        end
+
+        if type == :none && (number.present? || min.present? || max.present?)
+          raise ArgumentError, "Do not specify both `number`, `min` or `max` with `named_args :none`"
+        end
+
+        @named_args_type = type
+
+        if type == :none
+          @max_named_args = 0
+        elsif number.present?
+          @min_named_args = @max_named_args = number
+        elsif min.present? || max.present?
+          @min_named_args = min
+          @max_named_args = max
+        end
+      end
+
       def max_named(count)
+        # TODO: (2.8) uncomment for the next major/minor release
+        # odeprecated "`max_named`", "`named_args max:`"
+
         raise TypeError, "Unsupported type #{count.class.name} for max_named" unless count.is_a?(Integer)
 
         @max_named_args = count
       end
 
       def min_named(count_or_type)
+        # TODO: (2.8) uncomment for the next major/minor release
+        # odeprecated "`min_named`", "`named_args min:`"
+
         case count_or_type
         when Integer
           @min_named_args = count_or_type
-          @min_named_type = nil
+          @named_args_type = nil
         when Symbol
           @min_named_args = 1
-          @min_named_type = count_or_type
+          @named_args_type = count_or_type
         else
           raise TypeError, "Unsupported type #{count_or_type.class.name} for min_named"
         end
       end
 
       def named(count_or_type)
+        # TODO: (2.8) uncomment for the next major/minor release
+        # odeprecated "`named`", "`named_args`"
+
         case count_or_type
         when Integer
           @max_named_args = @min_named_args = count_or_type
-          @min_named_type = nil
+          @named_args_type = nil
         when Symbol
           @max_named_args = @min_named_args = 1
-          @min_named_type = count_or_type
+          @named_args_type = count_or_type
         else
           raise TypeError, "Unsupported type #{count_or_type.class.name} for named"
         end
@@ -480,15 +518,15 @@ module Homebrew
 
       def check_named_args(args)
         exception = if @min_named_args && args.size < @min_named_args
-          case @min_named_type
-          when :cask
-            Cask::CaskUnspecifiedError
-          when :formula
-            FormulaUnspecifiedError
-          when :formula_or_cask
-            FormulaOrCaskUnspecifiedError
-          when :keg
-            KegUnspecifiedError
+          if @named_args_type.present?
+            types = @named_args_type.is_a?(Array) ? @named_args_type : [@named_args_type]
+            if types.any? { |arg| arg.is_a? String }
+              MinNamedArgumentsError.new(@min_named_args)
+            else
+              list = types.map { |type| type.to_s.tr("_", " ") }
+              list = list.to_sentence two_words_connector: " or ", last_word_connector: " or "
+              UsageError.new("this command requires a #{list} argument")
+            end
           else
             MinNamedArgumentsError.new(@min_named_args)
           end
diff --git a/Library/Homebrew/cmd/--cache.rb b/Library/Homebrew/cmd/--cache.rb
index 0641cc0613..3ea31bdffa 100644
--- a/Library/Homebrew/cmd/--cache.rb
+++ b/Library/Homebrew/cmd/--cache.rb
@@ -32,6 +32,8 @@ module Homebrew
              description: "Only show cache files for casks."
       conflicts "--build-from-source", "--force-bottle"
       conflicts "--formula", "--cask"
+
+      named_args [:formula, :cask]
     end
   end
 
diff --git a/Library/Homebrew/cmd/--caskroom.rb b/Library/Homebrew/cmd/--caskroom.rb
index 6facedc9c8..cf65933cb2 100644
--- a/Library/Homebrew/cmd/--caskroom.rb
+++ b/Library/Homebrew/cmd/--caskroom.rb
@@ -17,6 +17,8 @@ module Homebrew
         If <cask> is provided, display the location in the Caskroom where <cask>
         would be installed, without any sort of versioned directory as the last path.
       EOS
+
+      named_args :cask
     end
   end
 
diff --git a/Library/Homebrew/cmd/--cellar.rb b/Library/Homebrew/cmd/--cellar.rb
index a4be852c20..a6f88377a3 100644
--- a/Library/Homebrew/cmd/--cellar.rb
+++ b/Library/Homebrew/cmd/--cellar.rb
@@ -17,6 +17,8 @@ module Homebrew
         If <formula> is provided, display the location in the Cellar where <formula>
         would be installed, without any sort of versioned directory as the last path.
       EOS
+
+      named_args :formula
     end
   end
 
diff --git a/Library/Homebrew/cmd/--env.rb b/Library/Homebrew/cmd/--env.rb
index b8c9107e05..483a6c0b0d 100644
--- a/Library/Homebrew/cmd/--env.rb
+++ b/Library/Homebrew/cmd/--env.rb
@@ -27,6 +27,8 @@ module Homebrew
                           "or `--shell=auto` to detect the current shell."
       switch "--plain",
              description: "Generate plain output even when piped."
+
+      named_args :formula
     end
   end
 
diff --git a/Library/Homebrew/cmd/--prefix.rb b/Library/Homebrew/cmd/--prefix.rb
index 8e281c7764..dce8c6e8c1 100644
--- a/Library/Homebrew/cmd/--prefix.rb
+++ b/Library/Homebrew/cmd/--prefix.rb
@@ -25,6 +25,8 @@ module Homebrew
       EOS
       switch "--unbrewed",
              description: "List files in Homebrew's prefix not installed by Homebrew."
+
+      named_args :formula
     end
   end
 
diff --git a/Library/Homebrew/cmd/--repository.rb b/Library/Homebrew/cmd/--repository.rb
index 3f68fa9c4c..4a301ae45d 100644
--- a/Library/Homebrew/cmd/--repository.rb
+++ b/Library/Homebrew/cmd/--repository.rb
@@ -18,6 +18,8 @@ module Homebrew
 
         If <user>`/`<repo> are provided, display where tap <user>`/`<repo>'s directory is located.
       EOS
+
+      named_args :tap
     end
   end
 
@@ -27,7 +29,7 @@ module Homebrew
     if args.no_named?
       puts HOMEBREW_REPOSITORY
     else
-      puts args.named.map { |tap| Tap.fetch(tap).path }
+      puts args.named.to_taps.map(&:path)
     end
   end
 end
diff --git a/Library/Homebrew/cmd/--version.rb b/Library/Homebrew/cmd/--version.rb
index de305d3579..5a06e7efed 100644
--- a/Library/Homebrew/cmd/--version.rb
+++ b/Library/Homebrew/cmd/--version.rb
@@ -18,7 +18,7 @@ module Homebrew
         (if tapped) to standard output.
       EOS
 
-      max_named 0
+      named_args :none
     end
   end
 
diff --git a/Library/Homebrew/cmd/analytics.rb b/Library/Homebrew/cmd/analytics.rb
index aa64043274..a1b296835b 100644
--- a/Library/Homebrew/cmd/analytics.rb
+++ b/Library/Homebrew/cmd/analytics.rb
@@ -27,7 +27,7 @@ module Homebrew
         Regenerate the UUID used for Homebrew's analytics.
       EOS
 
-      max_named 1
+      named_args %w[state on off regenerate-uuid], max: 1
     end
   end
 
diff --git a/Library/Homebrew/cmd/autoremove.rb b/Library/Homebrew/cmd/autoremove.rb
index e65d3a59b0..51b5b07047 100644
--- a/Library/Homebrew/cmd/autoremove.rb
+++ b/Library/Homebrew/cmd/autoremove.rb
@@ -18,7 +18,7 @@ module Homebrew
       switch "-n", "--dry-run",
              description: "List what would be uninstalled, but do not actually uninstall anything."
 
-      max_named 0
+      named_args :none
     end
   end
 
diff --git a/Library/Homebrew/cmd/cleanup.rb b/Library/Homebrew/cmd/cleanup.rb
index 2900e3e2da..290bac0618 100644
--- a/Library/Homebrew/cmd/cleanup.rb
+++ b/Library/Homebrew/cmd/cleanup.rb
@@ -31,6 +31,8 @@ module Homebrew
                           "If you want to delete those too: `rm -rf \"$(brew --cache)\"`"
       switch "--prune-prefix",
              description: "Only prune the symlinks and directories from the prefix and remove no other files."
+
+      named_args [:formula, :cask]
     end
   end
 
diff --git a/Library/Homebrew/cmd/commands.rb b/Library/Homebrew/cmd/commands.rb
index 92fed7e063..137b3de924 100644
--- a/Library/Homebrew/cmd/commands.rb
+++ b/Library/Homebrew/cmd/commands.rb
@@ -22,7 +22,7 @@ module Homebrew
              depends_on:  "--quiet",
              description: "Include aliases of internal commands."
 
-      max_named 0
+      named_args :none
     end
   end
 
diff --git a/Library/Homebrew/cmd/completions.rb b/Library/Homebrew/cmd/completions.rb
index 3aad3aa9c8..d0a6ebcc96 100644
--- a/Library/Homebrew/cmd/completions.rb
+++ b/Library/Homebrew/cmd/completions.rb
@@ -25,7 +25,7 @@ module Homebrew
         Link or unlink Homebrew's completions.
       EOS
 
-      max_named 1
+      named_args %w[state link unlink], max: 1
     end
   end
 
diff --git a/Library/Homebrew/cmd/config.rb b/Library/Homebrew/cmd/config.rb
index 3153cdd54b..7a93e543d5 100644
--- a/Library/Homebrew/cmd/config.rb
+++ b/Library/Homebrew/cmd/config.rb
@@ -19,7 +19,7 @@ module Homebrew
         a bug report, you will be required to provide this information.
       EOS
 
-      max_named 0
+      named_args :none
     end
   end
 
diff --git a/Library/Homebrew/cmd/deps.rb b/Library/Homebrew/cmd/deps.rb
index bddd8cd80d..1ed15e5d3d 100644
--- a/Library/Homebrew/cmd/deps.rb
+++ b/Library/Homebrew/cmd/deps.rb
@@ -66,6 +66,8 @@ module Homebrew
       conflicts "--installed", "--all"
       conflicts "--formula", "--cask"
       formula_options
+
+      named_args [:formula, :cask]
     end
   end
 
diff --git a/Library/Homebrew/cmd/desc.rb b/Library/Homebrew/cmd/desc.rb
index b2b0b8675e..6c4b9344fb 100644
--- a/Library/Homebrew/cmd/desc.rb
+++ b/Library/Homebrew/cmd/desc.rb
@@ -34,7 +34,8 @@ module Homebrew
                           "it is interpreted as a regular expression."
 
       conflicts "--search", "--name", "--description"
-      min_named 1
+
+      named_args :formula
     end
   end
 
@@ -50,10 +51,14 @@ module Homebrew
     end
 
     results = if search_type.nil?
+      raise FormulaUnspecifiedError if args.no_named?
+
       desc = {}
       args.named.to_formulae.each { |f| desc[f.full_name] = f.desc }
       Descriptions.new(desc)
     else
+      raise UsageError, "this command requires a search term" if args.no_named?
+
       query = args.named.join(" ")
       string_or_regex = query_regexp(query)
       CacheStoreDatabase.use(:descriptions) do |db|
diff --git a/Library/Homebrew/cmd/doctor.rb b/Library/Homebrew/cmd/doctor.rb
index b243cd802f..b43b7a4c37 100644
--- a/Library/Homebrew/cmd/doctor.rb
+++ b/Library/Homebrew/cmd/doctor.rb
@@ -27,6 +27,8 @@ module Homebrew
                           "if provided as arguments."
       switch "-D", "--audit-debug",
              description: "Enable debugging and profiling of audit methods."
+
+      named_args :diagnostic_check
     end
   end
 
diff --git a/Library/Homebrew/cmd/fetch.rb b/Library/Homebrew/cmd/fetch.rb
index 7736cc249d..978d944d42 100644
--- a/Library/Homebrew/cmd/fetch.rb
+++ b/Library/Homebrew/cmd/fetch.rb
@@ -58,7 +58,7 @@ module Homebrew
       conflicts "--cask", "--build-bottle"
       conflicts "--cask", "--force-bottle"
 
-      min_named :formula_or_cask
+      named_args [:formula, :cask], min: 1
     end
   end
 
diff --git a/Library/Homebrew/cmd/gist-logs.rb b/Library/Homebrew/cmd/gist-logs.rb
index b8735643b4..a94d7c4513 100644
--- a/Library/Homebrew/cmd/gist-logs.rb
+++ b/Library/Homebrew/cmd/gist-logs.rb
@@ -33,7 +33,7 @@ module Homebrew
              description: "The Gist will be marked private and will not appear in listings but will "\
                           "be accessible with its link."
 
-      named :formula
+      named_args :formula, number: 1
     end
   end
 
diff --git a/Library/Homebrew/cmd/home.rb b/Library/Homebrew/cmd/home.rb
index 89ca716e6b..58d7c1126a 100644
--- a/Library/Homebrew/cmd/home.rb
+++ b/Library/Homebrew/cmd/home.rb
@@ -23,6 +23,8 @@ module Homebrew
       switch "--cask", "--casks",
              description: "Treat all named arguments as casks."
       conflicts "--formula", "--cask"
+
+      named_args [:formula, :cask]
     end
   end
 
diff --git a/Library/Homebrew/cmd/info.rb b/Library/Homebrew/cmd/info.rb
index 2d6032f5e1..7956ac39f8 100644
--- a/Library/Homebrew/cmd/info.rb
+++ b/Library/Homebrew/cmd/info.rb
@@ -68,6 +68,8 @@ module Homebrew
       conflicts "--formula", "--cask"
 
       conflicts "--installed", "--all"
+
+      named_args [:formula, :cask]
     end
   end
 
diff --git a/Library/Homebrew/cmd/install.rb b/Library/Homebrew/cmd/install.rb
index 292bd59b7a..06fc5e2504 100644
--- a/Library/Homebrew/cmd/install.rb
+++ b/Library/Homebrew/cmd/install.rb
@@ -125,7 +125,8 @@ module Homebrew
 
       conflicts "--ignore-dependencies", "--only-dependencies"
       conflicts "--build-from-source", "--build-bottle", "--force-bottle"
-      min_named :formula_or_cask
+
+      named_args [:formula, :cask], min: 1
     end
   end
 
diff --git a/Library/Homebrew/cmd/leaves.rb b/Library/Homebrew/cmd/leaves.rb
index 11563f2e30..04efcdd3b9 100644
--- a/Library/Homebrew/cmd/leaves.rb
+++ b/Library/Homebrew/cmd/leaves.rb
@@ -18,7 +18,7 @@ module Homebrew
         List installed formulae that are not dependencies of another installed formula.
       EOS
 
-      max_named 0
+      named_args :none
     end
   end
 
diff --git a/Library/Homebrew/cmd/link.rb b/Library/Homebrew/cmd/link.rb
index b8a3204712..29365dd003 100644
--- a/Library/Homebrew/cmd/link.rb
+++ b/Library/Homebrew/cmd/link.rb
@@ -29,7 +29,7 @@ module Homebrew
       switch "-f", "--force",
              description: "Allow keg-only formulae to be linked."
 
-      min_named :keg
+      named_args :installed_formula, min: 1
     end
   end
 
diff --git a/Library/Homebrew/cmd/list.rb b/Library/Homebrew/cmd/list.rb
index ab38eae271..57446422e6 100644
--- a/Library/Homebrew/cmd/list.rb
+++ b/Library/Homebrew/cmd/list.rb
@@ -72,6 +72,8 @@ module Homebrew
         conflicts "--full-name", flag
         conflicts "--cask", flag
       end
+
+      named_args [:installed_formula, :installed_cask]
     end
   end
 
diff --git a/Library/Homebrew/cmd/log.rb b/Library/Homebrew/cmd/log.rb
index 391d213f52..981c36c9cf 100644
--- a/Library/Homebrew/cmd/log.rb
+++ b/Library/Homebrew/cmd/log.rb
@@ -30,7 +30,8 @@ module Homebrew
              description: "Print only a specified number of commits."
 
       conflicts "-1", "--max-count"
-      max_named 1
+
+      named_args :formula, max: 1
     end
   end
 
diff --git a/Library/Homebrew/cmd/migrate.rb b/Library/Homebrew/cmd/migrate.rb
index 6f7cfbca13..e2455dc6b5 100644
--- a/Library/Homebrew/cmd/migrate.rb
+++ b/Library/Homebrew/cmd/migrate.rb
@@ -22,7 +22,7 @@ module Homebrew
              description: "Treat installed <formula> and provided <formula> as if they are from "\
                           "the same taps and migrate them anyway."
 
-      min_named :formula
+      named_args :installed_formula, min: 1
     end
   end
 
diff --git a/Library/Homebrew/cmd/missing.rb b/Library/Homebrew/cmd/missing.rb
index 4eabe779ee..1b0f2ef1d6 100644
--- a/Library/Homebrew/cmd/missing.rb
+++ b/Library/Homebrew/cmd/missing.rb
@@ -24,6 +24,8 @@ module Homebrew
       comma_array "--hide",
                   description: "Act as if none of the specified <hidden> are installed. <hidden> should be "\
                                "a comma-separated list of formulae."
+
+      named_args :formula
     end
   end
 
diff --git a/Library/Homebrew/cmd/options.rb b/Library/Homebrew/cmd/options.rb
index b94c0aa6f3..f87a2f81ec 100644
--- a/Library/Homebrew/cmd/options.rb
+++ b/Library/Homebrew/cmd/options.rb
@@ -29,6 +29,8 @@ module Homebrew
              description: "Show options for the specified <command>."
 
       conflicts "--installed", "--all", "--command"
+
+      named_args :formula
     end
   end
 
diff --git a/Library/Homebrew/cmd/outdated.rb b/Library/Homebrew/cmd/outdated.rb
index 2a41e1752f..112fcf0cd4 100644
--- a/Library/Homebrew/cmd/outdated.rb
+++ b/Library/Homebrew/cmd/outdated.rb
@@ -42,6 +42,8 @@ module Homebrew
 
       conflicts "--quiet", "--verbose", "--json"
       conflicts "--formula", "--cask"
+
+      named_args [:formula, :cask]
     end
   end
 
diff --git a/Library/Homebrew/cmd/pin.rb b/Library/Homebrew/cmd/pin.rb
index ce0b48ffa7..c9367ea006 100644
--- a/Library/Homebrew/cmd/pin.rb
+++ b/Library/Homebrew/cmd/pin.rb
@@ -19,7 +19,7 @@ module Homebrew
         issuing the `brew upgrade` <formula> command. See also `unpin`.
       EOS
 
-      min_named :formula
+      named_args :installed_formula, min: 1
     end
   end
 
diff --git a/Library/Homebrew/cmd/postinstall.rb b/Library/Homebrew/cmd/postinstall.rb
index de70cae3d5..a1d5cb2ff7 100644
--- a/Library/Homebrew/cmd/postinstall.rb
+++ b/Library/Homebrew/cmd/postinstall.rb
@@ -19,7 +19,7 @@ module Homebrew
         Rerun the post-install steps for <formula>.
       EOS
 
-      min_named :keg
+      named_args :installed_formula, min: 1
     end
   end
 
diff --git a/Library/Homebrew/cmd/readall.rb b/Library/Homebrew/cmd/readall.rb
index 353733bc9d..0ee287edef 100644
--- a/Library/Homebrew/cmd/readall.rb
+++ b/Library/Homebrew/cmd/readall.rb
@@ -24,6 +24,8 @@ module Homebrew
              description: "Verify any alias symlinks in each tap."
       switch "--syntax",
              description: "Syntax-check all of Homebrew's Ruby files (if no `<tap>` is passed)."
+
+      named_args :tap
     end
   end
 
@@ -41,7 +43,7 @@ module Homebrew
     taps = if args.no_named?
       Tap
     else
-      args.named.map { |t| Tap.fetch(t) }
+      args.named.to_installed_taps
     end
     taps.each do |tap|
       Homebrew.failed = true unless Readall.valid_tap?(tap, options)
diff --git a/Library/Homebrew/cmd/reinstall.rb b/Library/Homebrew/cmd/reinstall.rb
index 1f1c87d417..8ac00a61f4 100644
--- a/Library/Homebrew/cmd/reinstall.rb
+++ b/Library/Homebrew/cmd/reinstall.rb
@@ -75,7 +75,8 @@ module Homebrew
       cask_options
 
       conflicts "--build-from-source", "--force-bottle"
-      min_named :formula_or_cask
+
+      named_args [:formula, :cask], min: 1
     end
   end
 
diff --git a/Library/Homebrew/cmd/search.rb b/Library/Homebrew/cmd/search.rb
index 346b7beae1..0b08fa14ea 100644
--- a/Library/Homebrew/cmd/search.rb
+++ b/Library/Homebrew/cmd/search.rb
@@ -66,6 +66,9 @@ module Homebrew
 
       conflicts("--desc", "--pull-request")
       conflicts(*package_manager_switches)
+
+      # TODO: (2.9) uncomment when the `odeprecated`/`odisabled` for `brew search` with no arguments is removed
+      # named_args min: 1
     end
   end
 
diff --git a/Library/Homebrew/cmd/tap-info.rb b/Library/Homebrew/cmd/tap-info.rb
index 4d6cd7436d..29bff4ddf0 100644
--- a/Library/Homebrew/cmd/tap-info.rb
+++ b/Library/Homebrew/cmd/tap-info.rb
@@ -24,6 +24,8 @@ module Homebrew
              description: "Print a JSON representation of <tap>. Currently the default and only accepted "\
                           "value for <version> is `v1`. See the docs for examples of using the JSON "\
                           "output: <https://docs.brew.sh/Querying-Brew>"
+
+      named_args :tap
     end
   end
 
@@ -33,9 +35,7 @@ module Homebrew
     taps = if args.installed?
       Tap
     else
-      args.named.sort.map do |name|
-        Tap.fetch(name)
-      end
+      args.named.to_taps
     end
 
     if args.json
diff --git a/Library/Homebrew/cmd/tap.rb b/Library/Homebrew/cmd/tap.rb
index 8fe4f1a5be..13661a4f0b 100644
--- a/Library/Homebrew/cmd/tap.rb
+++ b/Library/Homebrew/cmd/tap.rb
@@ -41,7 +41,7 @@ module Homebrew
       switch "--list-pinned",
              description: "List all pinned taps."
 
-      max_named 2
+      named_args :tap, max: 2
     end
   end
 
diff --git a/Library/Homebrew/cmd/uninstall.rb b/Library/Homebrew/cmd/uninstall.rb
index 179fdc032c..5d76f42b01 100644
--- a/Library/Homebrew/cmd/uninstall.rb
+++ b/Library/Homebrew/cmd/uninstall.rb
@@ -40,7 +40,7 @@ module Homebrew
              description: "Treat all named arguments as casks."
       conflicts "--formula", "--cask"
 
-      min_named :formula_or_cask
+      named_args [:installed_formula, :installed_cask], min: 1
     end
   end
 
diff --git a/Library/Homebrew/cmd/unlink.rb b/Library/Homebrew/cmd/unlink.rb
index 43a9a8dca1..02bbbab6e8 100644
--- a/Library/Homebrew/cmd/unlink.rb
+++ b/Library/Homebrew/cmd/unlink.rb
@@ -24,7 +24,7 @@ module Homebrew
              description: "List files which would be unlinked without actually unlinking or "\
                           "deleting any files."
 
-      min_named :keg
+      named_args :installed_formula, min: 1
     end
   end
 
diff --git a/Library/Homebrew/cmd/unpin.rb b/Library/Homebrew/cmd/unpin.rb
index 0c1b7fcbcf..f763a80e1b 100644
--- a/Library/Homebrew/cmd/unpin.rb
+++ b/Library/Homebrew/cmd/unpin.rb
@@ -19,7 +19,7 @@ module Homebrew
         See also `pin`.
       EOS
 
-      min_named :formula
+      named_args :installed_formula, min: 1
     end
   end
 
diff --git a/Library/Homebrew/cmd/untap.rb b/Library/Homebrew/cmd/untap.rb
index 66529cc027..1bdb6b3f5b 100644
--- a/Library/Homebrew/cmd/untap.rb
+++ b/Library/Homebrew/cmd/untap.rb
@@ -17,15 +17,14 @@ module Homebrew
         Remove a tapped formula repository.
       EOS
 
-      min_named 1
+      named_args :tap, min: 1
     end
   end
 
   def untap
     args = untap_args.parse
 
-    args.named.each do |tapname|
-      tap = Tap.fetch(tapname)
+    args.named.to_installed_taps.each do |tap|
       odie "Untapping #{tap} is not allowed" if tap.core_tap?
 
       installed_tap_formulae = Formula.installed.select { |formula| formula.tap == tap }
diff --git a/Library/Homebrew/cmd/upgrade.rb b/Library/Homebrew/cmd/upgrade.rb
index f134f773e8..038083fcff 100644
--- a/Library/Homebrew/cmd/upgrade.rb
+++ b/Library/Homebrew/cmd/upgrade.rb
@@ -89,6 +89,8 @@ module Homebrew
       cask_options
 
       conflicts "--build-from-source", "--force-bottle"
+
+      named_args [:installed_formula, :installed_cask]
     end
   end
 
diff --git a/Library/Homebrew/cmd/uses.rb b/Library/Homebrew/cmd/uses.rb
index a16c763035..7ad2e3c6a4 100644
--- a/Library/Homebrew/cmd/uses.rb
+++ b/Library/Homebrew/cmd/uses.rb
@@ -46,7 +46,8 @@ module Homebrew
              description: "Include only casks."
 
       conflicts "--formula", "--cask"
-      min_named :formula
+
+      named_args :formula, min: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/audit.rb b/Library/Homebrew/dev-cmd/audit.rb
index 264239680d..3a8e3fcfa0 100644
--- a/Library/Homebrew/dev-cmd/audit.rb
+++ b/Library/Homebrew/dev-cmd/audit.rb
@@ -90,6 +90,8 @@ module Homebrew
       conflicts "--display-cop-names", "--skip-style"
       conflicts "--display-cop-names", "--only-cops"
       conflicts "--display-cop-names", "--except-cops"
+
+      named_args [:formula, :cask]
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/bottle.rb b/Library/Homebrew/dev-cmd/bottle.rb
index f406ce4344..02b46eb88b 100644
--- a/Library/Homebrew/dev-cmd/bottle.rb
+++ b/Library/Homebrew/dev-cmd/bottle.rb
@@ -86,7 +86,8 @@ module Homebrew
              description: "Use the specified <URL> as the root of the bottle's URL instead of Homebrew's default."
 
       conflicts "--no-rebuild", "--keep-old"
-      min_named 1
+
+      named_args :installed_formula, min: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/bump-cask-pr.rb b/Library/Homebrew/dev-cmd/bump-cask-pr.rb
index 56a4841802..d9c7c3f66b 100644
--- a/Library/Homebrew/dev-cmd/bump-cask-pr.rb
+++ b/Library/Homebrew/dev-cmd/bump-cask-pr.rb
@@ -52,7 +52,8 @@ module Homebrew
 
       conflicts "--dry-run", "--write"
       conflicts "--no-audit", "--online"
-      named 1
+
+      named_args :cask, number: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/bump-formula-pr.rb b/Library/Homebrew/dev-cmd/bump-formula-pr.rb
index 93f9b0cd61..c038cf9d99 100644
--- a/Library/Homebrew/dev-cmd/bump-formula-pr.rb
+++ b/Library/Homebrew/dev-cmd/bump-formula-pr.rb
@@ -79,7 +79,8 @@ module Homebrew
       conflicts "--no-audit", "--strict"
       conflicts "--no-audit", "--online"
       conflicts "--url", "--tag"
-      max_named 1
+
+      named_args :formula, max: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/bump-revision.rb b/Library/Homebrew/dev-cmd/bump-revision.rb
index ba33a6494c..c15adc09d1 100644
--- a/Library/Homebrew/dev-cmd/bump-revision.rb
+++ b/Library/Homebrew/dev-cmd/bump-revision.rb
@@ -23,7 +23,7 @@ module Homebrew
       flag   "--message=",
              description: "Append <message> to the default commit message."
 
-      min_named :formula
+      named_args :formula, min: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/bump-unversioned-casks.rb b/Library/Homebrew/dev-cmd/bump-unversioned-casks.rb
index 9712474d5d..83811e9651 100644
--- a/Library/Homebrew/dev-cmd/bump-unversioned-casks.rb
+++ b/Library/Homebrew/dev-cmd/bump-unversioned-casks.rb
@@ -29,7 +29,7 @@ module Homebrew
       flag   "--state-file=",
              description: "File for caching state."
 
-      min_named 1
+      named_args [:cask, :tap], min: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/bump.rb b/Library/Homebrew/dev-cmd/bump.rb
index adf8878735..9e23cb6bdf 100644
--- a/Library/Homebrew/dev-cmd/bump.rb
+++ b/Library/Homebrew/dev-cmd/bump.rb
@@ -21,6 +21,8 @@ module Homebrew
              description: "Limit number of package results returned."
       switch :verbose
       switch :debug
+
+      named_args :formula
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/cat.rb b/Library/Homebrew/dev-cmd/cat.rb
index 3cdb7acb82..6c49fd8fab 100644
--- a/Library/Homebrew/dev-cmd/cat.rb
+++ b/Library/Homebrew/dev-cmd/cat.rb
@@ -23,7 +23,7 @@ module Homebrew
              description: "Treat all named arguments as casks."
       conflicts "--formula", "--cask"
 
-      named :formula_or_cask
+      named_args [:formula, :cask], number: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/command.rb b/Library/Homebrew/dev-cmd/command.rb
index eb946cf636..8b9ecc6e24 100644
--- a/Library/Homebrew/dev-cmd/command.rb
+++ b/Library/Homebrew/dev-cmd/command.rb
@@ -18,7 +18,7 @@ module Homebrew
         Display the path to the file being used when invoking `brew` <cmd>.
       EOS
 
-      min_named 1
+      named_args :command, min: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/create.rb b/Library/Homebrew/dev-cmd/create.rb
index 3815de0604..3e9fbc359d 100644
--- a/Library/Homebrew/dev-cmd/create.rb
+++ b/Library/Homebrew/dev-cmd/create.rb
@@ -69,7 +69,7 @@ module Homebrew
       conflicts "--cask", "--HEAD"
       conflicts "--cask", "--set-license"
 
-      named 1
+      named_args number: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/dispatch-build-bottle.rb b/Library/Homebrew/dev-cmd/dispatch-build-bottle.rb
index 9732e9bce6..f160bd8696 100644
--- a/Library/Homebrew/dev-cmd/dispatch-build-bottle.rb
+++ b/Library/Homebrew/dev-cmd/dispatch-build-bottle.rb
@@ -28,7 +28,7 @@ module Homebrew
       switch "--upload",
              description: "Upload built bottles to Bintray."
 
-      min_named :formula
+      named_args :formula, min: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/edit.rb b/Library/Homebrew/dev-cmd/edit.rb
index 0894b3f00b..83505116dd 100644
--- a/Library/Homebrew/dev-cmd/edit.rb
+++ b/Library/Homebrew/dev-cmd/edit.rb
@@ -24,6 +24,8 @@ module Homebrew
       switch "--cask", "--casks",
              description: "Treat all named arguments as casks."
       conflicts "--formula", "--cask"
+
+      named_args [:formula, :cask]
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/extract.rb b/Library/Homebrew/dev-cmd/extract.rb
index 63f518f69f..7cb5c238da 100644
--- a/Library/Homebrew/dev-cmd/extract.rb
+++ b/Library/Homebrew/dev-cmd/extract.rb
@@ -97,7 +97,7 @@ module Homebrew
       switch "-f", "--force",
              description: "Overwrite the destination formula if it already exists."
 
-      named 2
+      named_args :formula, number: 2
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/formula.rb b/Library/Homebrew/dev-cmd/formula.rb
index 17bfd4a806..39f960eb4b 100644
--- a/Library/Homebrew/dev-cmd/formula.rb
+++ b/Library/Homebrew/dev-cmd/formula.rb
@@ -18,7 +18,7 @@ module Homebrew
         Display the path where <formula> is located.
       EOS
 
-      min_named :formula
+      named_args :formula, min: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/install-bundler-gems.rb b/Library/Homebrew/dev-cmd/install-bundler-gems.rb
index d1c3bd88d6..419e5eee6c 100644
--- a/Library/Homebrew/dev-cmd/install-bundler-gems.rb
+++ b/Library/Homebrew/dev-cmd/install-bundler-gems.rb
@@ -18,7 +18,7 @@ module Homebrew
         Install Homebrew's Bundler gems.
       EOS
 
-      max_named 0
+      named_args :none
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/linkage.rb b/Library/Homebrew/dev-cmd/linkage.rb
index 63ae8066a1..dcd7782403 100644
--- a/Library/Homebrew/dev-cmd/linkage.rb
+++ b/Library/Homebrew/dev-cmd/linkage.rb
@@ -28,6 +28,8 @@ module Homebrew
       switch "--cached",
              description: "Print the cached linkage values stored in `HOMEBREW_CACHE`, set by a previous "\
                           "`brew linkage` run."
+
+      named_args :installed_formula
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/livecheck.rb b/Library/Homebrew/dev-cmd/livecheck.rb
index a074f51933..b27443b2cd 100644
--- a/Library/Homebrew/dev-cmd/livecheck.rb
+++ b/Library/Homebrew/dev-cmd/livecheck.rb
@@ -49,6 +49,8 @@ module Homebrew
       conflicts "--debug", "--json"
       conflicts "--tap=", "--all", "--installed"
       conflicts "--cask", "--formula"
+
+      named_args [:formula, :cask]
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/man.rb b/Library/Homebrew/dev-cmd/man.rb
index 06372647ea..e0f6ce82f4 100644
--- a/Library/Homebrew/dev-cmd/man.rb
+++ b/Library/Homebrew/dev-cmd/man.rb
@@ -31,7 +31,7 @@ module Homebrew
       switch "--link",
              description: "This is now done automatically by `brew update`."
 
-      max_named 0
+      named_args :none
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/mirror.rb b/Library/Homebrew/dev-cmd/mirror.rb
index ec6f44d8fc..435923c0cd 100644
--- a/Library/Homebrew/dev-cmd/mirror.rb
+++ b/Library/Homebrew/dev-cmd/mirror.rb
@@ -24,7 +24,7 @@ module Homebrew
       switch "--no-publish",
              description: "Upload to Bintray, but don't publish."
 
-      min_named :formula
+      named_args :formula, min: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/pr-automerge.rb b/Library/Homebrew/dev-cmd/pr-automerge.rb
index 9b4b5c41cb..0e582b168a 100644
--- a/Library/Homebrew/dev-cmd/pr-automerge.rb
+++ b/Library/Homebrew/dev-cmd/pr-automerge.rb
@@ -34,7 +34,7 @@ module Homebrew
       switch "--ignore-failures",
              description: "Include pull requests that have failing status checks."
 
-      max_named 0
+      named_args :none
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/pr-publish.rb b/Library/Homebrew/dev-cmd/pr-publish.rb
index de376b1cee..7e38180d50 100644
--- a/Library/Homebrew/dev-cmd/pr-publish.rb
+++ b/Library/Homebrew/dev-cmd/pr-publish.rb
@@ -29,7 +29,7 @@ module Homebrew
       flag   "--workflow=",
              description: "Target workflow filename (default: `publish-commit-bottles.yml`)."
 
-      min_named 1
+      named_args number: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/pr-pull.rb b/Library/Homebrew/dev-cmd/pr-pull.rb
index d35caf73fa..ce569c7afd 100644
--- a/Library/Homebrew/dev-cmd/pr-pull.rb
+++ b/Library/Homebrew/dev-cmd/pr-pull.rb
@@ -70,7 +70,8 @@ module Homebrew
                   description: "Comma-separated list of workflows which can be ignored if they have not been run."
 
       conflicts "--clean", "--autosquash"
-      min_named 1
+
+      named_args number: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/pr-upload.rb b/Library/Homebrew/dev-cmd/pr-upload.rb
index 1daa6cf19d..584696d4e4 100644
--- a/Library/Homebrew/dev-cmd/pr-upload.rb
+++ b/Library/Homebrew/dev-cmd/pr-upload.rb
@@ -33,6 +33,8 @@ module Homebrew
              description: "Upload to the specified Bintray organisation (default: `homebrew`)."
       flag   "--root-url=",
              description: "Use the specified <URL> as the root of the bottle's URL instead of Homebrew's default."
+
+      named_args :none
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/prof.rb b/Library/Homebrew/dev-cmd/prof.rb
index add6a5ae01..c57829fb95 100644
--- a/Library/Homebrew/dev-cmd/prof.rb
+++ b/Library/Homebrew/dev-cmd/prof.rb
@@ -18,6 +18,8 @@ module Homebrew
       EOS
       switch "--stackprof",
              description: "Use `stackprof` instead of `ruby-prof` (the default)."
+
+      named_args :command
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/release-notes.rb b/Library/Homebrew/dev-cmd/release-notes.rb
index 004915f284..c09eb35031 100644
--- a/Library/Homebrew/dev-cmd/release-notes.rb
+++ b/Library/Homebrew/dev-cmd/release-notes.rb
@@ -25,7 +25,7 @@ module Homebrew
       switch "--markdown",
              description: "Print as a Markdown list."
 
-      max_named 2
+      named_args max: 2
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/sh.rb b/Library/Homebrew/dev-cmd/sh.rb
index ca5afd9df0..c8ee8ff7bb 100644
--- a/Library/Homebrew/dev-cmd/sh.rb
+++ b/Library/Homebrew/dev-cmd/sh.rb
@@ -27,7 +27,7 @@ module Homebrew
       flag   "-c=", "--cmd=",
              description: "Execute commands in a non-interactive shell."
 
-      max_named 1
+      named_args max: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/sponsors.rb b/Library/Homebrew/dev-cmd/sponsors.rb
index b6d03a839d..27bf7ba277 100644
--- a/Library/Homebrew/dev-cmd/sponsors.rb
+++ b/Library/Homebrew/dev-cmd/sponsors.rb
@@ -17,6 +17,8 @@ module Homebrew
 
         Print a Markdown summary of Homebrew's GitHub Sponsors, suitable for pasting into a README.
       EOS
+
+      named_args :none
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/style.rb b/Library/Homebrew/dev-cmd/style.rb
index d43bd19f9a..df9e5bf302 100644
--- a/Library/Homebrew/dev-cmd/style.rb
+++ b/Library/Homebrew/dev-cmd/style.rb
@@ -42,6 +42,8 @@ module Homebrew
 
       conflicts "--formula", "--cask"
       conflicts "--only-cops", "--except-cops"
+
+      named_args [:formula, :cask, :tap]
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/tap-new.rb b/Library/Homebrew/dev-cmd/tap-new.rb
index fb63340591..a1665c44d3 100644
--- a/Library/Homebrew/dev-cmd/tap-new.rb
+++ b/Library/Homebrew/dev-cmd/tap-new.rb
@@ -26,7 +26,8 @@ module Homebrew
              description: "Initialize Git repository with the specified branch name (default: `main`)."
 
       conflicts "--no-git", "--branch"
-      named 1
+
+      named_args :tap, number: 1
     end
   end
 
@@ -36,8 +37,7 @@ module Homebrew
     label = args.pull_label || "pr-pull"
     branch = args.branch || "main"
 
-    tap_name = args.named.first
-    tap = Tap.fetch(tap_name)
+    tap = args.named.to_taps.first
     raise "Invalid tap name '#{tap_name}'" unless tap.path.to_s.match?(HOMEBREW_TAP_PATH_REGEX)
 
     titleized_user = tap.user.dup
diff --git a/Library/Homebrew/dev-cmd/test.rb b/Library/Homebrew/dev-cmd/test.rb
index b45cd1dfab..0cd00db0f4 100644
--- a/Library/Homebrew/dev-cmd/test.rb
+++ b/Library/Homebrew/dev-cmd/test.rb
@@ -30,7 +30,7 @@ module Homebrew
       switch "--retry",
              description: "Retry if a testing fails."
 
-      min_named :formula
+      named_args :installed_formula, min: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/tests.rb b/Library/Homebrew/dev-cmd/tests.rb
index 1da41139bc..cf98431b93 100644
--- a/Library/Homebrew/dev-cmd/tests.rb
+++ b/Library/Homebrew/dev-cmd/tests.rb
@@ -34,7 +34,7 @@ module Homebrew
       flag   "--seed=",
              description: "Randomise tests with the specified <value> instead of a random seed."
 
-      max_named 0
+      named_args :none
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/typecheck.rb b/Library/Homebrew/dev-cmd/typecheck.rb
index 7dd326dc03..ccbe230b78 100644
--- a/Library/Homebrew/dev-cmd/typecheck.rb
+++ b/Library/Homebrew/dev-cmd/typecheck.rb
@@ -37,7 +37,8 @@ module Homebrew
                           "in their paths (relative to the input path passed to Sorbet)."
 
       conflicts "--dir", "--file"
-      max_named 0
+
+      named_args :none
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/unbottled.rb b/Library/Homebrew/dev-cmd/unbottled.rb
index f570b5e48a..31c1d7005b 100644
--- a/Library/Homebrew/dev-cmd/unbottled.rb
+++ b/Library/Homebrew/dev-cmd/unbottled.rb
@@ -24,6 +24,8 @@ module Homebrew
       switch "--total",
              description: "Output the number of unbottled and total formulae."
       conflicts "--dependents", "--total"
+
+      named_args :formula
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/unpack.rb b/Library/Homebrew/dev-cmd/unpack.rb
index 529bfcc046..ccce3a938c 100644
--- a/Library/Homebrew/dev-cmd/unpack.rb
+++ b/Library/Homebrew/dev-cmd/unpack.rb
@@ -30,7 +30,8 @@ module Homebrew
              description: "Overwrite the destination directory if it already exists."
 
       conflicts "--git", "--patch"
-      min_named :formula
+
+      named_args :formula, min: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/update-license-data.rb b/Library/Homebrew/dev-cmd/update-license-data.rb
index ef51979c7e..284ee6842c 100644
--- a/Library/Homebrew/dev-cmd/update-license-data.rb
+++ b/Library/Homebrew/dev-cmd/update-license-data.rb
@@ -21,7 +21,7 @@ module Homebrew
              description: "Return a failing status code if current license data's version is the same as " \
                           "the upstream. This can be used to notify CI when the SPDX license data is out of date."
 
-      max_named 0
+      named_args :none
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/update-python-resources.rb b/Library/Homebrew/dev-cmd/update-python-resources.rb
index a66710f516..e9883c99ac 100644
--- a/Library/Homebrew/dev-cmd/update-python-resources.rb
+++ b/Library/Homebrew/dev-cmd/update-python-resources.rb
@@ -34,7 +34,7 @@ module Homebrew
       comma_array "--exclude-packages=",
                   description: "Exclude these packages when finding resources."
 
-      min_named :formula
+      named_args :formula, number: 1
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/update-test.rb b/Library/Homebrew/dev-cmd/update-test.rb
index 789ec21aa9..3659375d1e 100644
--- a/Library/Homebrew/dev-cmd/update-test.rb
+++ b/Library/Homebrew/dev-cmd/update-test.rb
@@ -26,7 +26,7 @@ module Homebrew
       flag   "--before=",
              description: "Use the commit at the specified <date> as the start commit."
 
-      max_named 0
+      named_args :none
     end
   end
 
diff --git a/Library/Homebrew/dev-cmd/vendor-gems.rb b/Library/Homebrew/dev-cmd/vendor-gems.rb
index a9394c8905..1047daa96d 100644
--- a/Library/Homebrew/dev-cmd/vendor-gems.rb
+++ b/Library/Homebrew/dev-cmd/vendor-gems.rb
@@ -21,7 +21,7 @@ module Homebrew
       comma_array "--update",
                   description: "Update all vendored Gems to the latest version."
 
-      max_named 0
+      named_args :none
     end
   end
 
diff --git a/Library/Homebrew/test/cask/cmd/shared_examples/requires_cask_token.rb b/Library/Homebrew/test/cask/cmd/shared_examples/requires_cask_token.rb
index a3faaff589..c3eb1a0708 100644
--- a/Library/Homebrew/test/cask/cmd/shared_examples/requires_cask_token.rb
+++ b/Library/Homebrew/test/cask/cmd/shared_examples/requires_cask_token.rb
@@ -6,7 +6,7 @@ shared_examples "a command that requires a Cask token" do
     it "raises an exception " do
       expect {
         described_class.run
-      }.to raise_error(Cask::CaskUnspecifiedError, "This command requires a Cask token.")
+      }.to raise_error(UsageError, /this command requires a .*cask.* argument/)
     end
   end
 end
diff --git a/Library/Homebrew/test/cli/named_args_spec.rb b/Library/Homebrew/test/cli/named_args_spec.rb
index b8efc96cde..10fe73660c 100644
--- a/Library/Homebrew/test/cli/named_args_spec.rb
+++ b/Library/Homebrew/test/cli/named_args_spec.rb
@@ -162,4 +162,37 @@ describe Homebrew::CLI::NamedArgs do
       expect(described_class.new("foo", "baz").to_paths(only: :cask)).to eq [cask_path, Cask::CaskLoader.path("baz")]
     end
   end
+
+  describe "#to_taps" do
+    it "returns taps" do
+      taps = described_class.new("homebrew/foo", "bar/baz")
+      expect(taps.to_taps.map(&:name)).to eq %w[homebrew/foo bar/baz]
+    end
+
+    it "raises an error for invalid tap" do
+      taps = described_class.new("homebrew/foo", "barbaz")
+      expect { taps.to_taps }.to raise_error(RuntimeError, /Invalid tap name/)
+    end
+  end
+
+  describe "#to_installed_taps" do
+    before do
+      (HOMEBREW_REPOSITORY/"Library/Taps/homebrew/homebrew-foo").mkpath
+    end
+
+    it "returns installed taps" do
+      taps = described_class.new("homebrew/foo")
+      expect(taps.to_installed_taps.map(&:name)).to eq %w[homebrew/foo]
+    end
+
+    it "raises an error for uninstalled tap" do
+      taps = described_class.new("homebrew/foo", "bar/baz")
+      expect { taps.to_installed_taps }.to raise_error(TapUnavailableError)
+    end
+
+    it "raises an error for invalid tap" do
+      taps = described_class.new("homebrew/foo", "barbaz")
+      expect { taps.to_installed_taps }.to raise_error(RuntimeError, /Invalid tap name/)
+    end
+  end
 end