Share code between cask token and formula name audits.

Library/Homebrew/cask/audit.rb

@@ -8,6 +8,7 @@
 require "livecheck/livecheck"
 require "source_location"
 require "system_command"
+require "token_auditor"
 require "utils/curl"
 require "utils/git"
 require "utils/shared_audits"
@@ -391,6 +392,15 @@ def audit_languages
       end
     end
 
+    sig { void }
+    def audit_token
+      token_auditor = Homebrew::TokenAuditor.new(cask.token)
+      return if (errors = token_auditor.errors).empty?
+
+      add_error "Cask token '#{cask.token}' must not contain #{errors.to_sentence(two_words_connector: " or ",
+                                                                                  last_word_connector: " or ")}."
+    end
+
     sig { void }
     def audit_token_conflicts
       return unless token_conflicts?
@@ -405,27 +415,6 @@ def audit_token_conflicts
       end
     end
 
-    sig { void }
-    def audit_token_valid
-      add_error "cask token contains non-ascii characters" unless cask.token.ascii_only?
-      add_error "cask token + should be replaced by -plus-" if cask.token.include? "+"
-      add_error "cask token whitespace should be replaced by hyphens" if cask.token.include? " "
-      add_error "cask token underscores should be replaced by hyphens" if cask.token.include? "_"
-      add_error "cask token should not contain double hyphens" if cask.token.include? "--"
-
-      if cask.token.match?(/[^@a-z0-9-]/)
-        add_error "cask token should only contain lowercase alphanumeric characters, hyphens and @"
-      end
-
-      if cask.token.start_with?("-", "@") || cask.token.end_with?("-", "@")
-        add_error "cask token should not have leading or trailing hyphens and/or @"
-      end
-
-      add_error "cask token @ unrelated to versioning should be replaced by -at-" if cask.token.count("@") > 1
-      add_error "cask token should not contain a hyphen followed by @" if cask.token.include? "-@"
-      add_error "cask token should not contain @ followed by a hyphen" if cask.token.include? "@-"
-    end
-
     sig { void }
     def audit_token_bad_words
       return unless new_cask?

Library/Homebrew/formula_auditor.rb

@@ -3,6 +3,7 @@
 
 require "deprecate_disable"
 require "formula_versions"
+require "token_auditor"
 require "resource_auditor"
 require "utils/shared_audits"
 
@@ -160,10 +161,14 @@ def audit_synced_versions_formulae
       end
     end
 
-    def audit_formula_name
+    def audit_name
       name = formula.name
 
-      problem "Formula name '#{name}' must not contain uppercase letters." if name != name.downcase
+      token_auditor = Homebrew::TokenAuditor.new(name)
+      unless (errors = token_auditor.errors).empty?
+        problem "Formula name '#{name}' must not contain #{errors.to_sentence(two_words_connector: " or ",
+                                                                              last_word_connector: " or ")}."
+      end
 
       return unless @strict
       return unless @core_tap

Library/Homebrew/test/formula_auditor_spec.rb

@@ -476,7 +476,7 @@ class Foo < Formula
     end
   end
 
-  describe "#audit_formula_name" do
+  describe "#audit_name" do
     specify "no issue" do
       fa = formula_auditor "foo", <<~RUBY, core_tap: true, strict: true
         class Foo < Formula
@@ -485,7 +485,7 @@ class Foo < Formula
         end
       RUBY
 
-      fa.audit_formula_name
+      fa.audit_name
       expect(fa.problems).to be_empty
     end
 
@@ -497,7 +497,7 @@ class Foo < Formula
         end
       RUBY
 
-      fa.audit_formula_name
+      fa.audit_name
       expect(fa.problems.first[:message]).to match "must not contain uppercase letters"
     end
   end

Library/Homebrew/token_auditor.rb

@@ -0,0 +1,40 @@
+# typed: true
+# frozen_string_literal: true
+
+module Homebrew
+  class TokenAuditor
+    sig { returns(String) }
+    attr_reader :token
+
+    sig { params(token: String).void }
+    def initialize(token)
+      @token = token
+    end
+
+    sig { returns(T::Array[String]) }
+    def errors
+      errors = []
+
+      errors << "uppercase letters" if token.match?(/[A-Z]/)
+      errors << "whitespace" if token.match?(/\s/)
+      errors << "non-ASCII characters" unless token.ascii_only?
+      errors << "double hyphens" if token.include?("--")
+
+      # A bunch of formulae contain these:
+      # errors << "underscores" if token.include?("_")
+      # errors << "plus symbols" if token.include?("+")
+
+      errors << "a leading @" if token.start_with?("@")
+      errors << "a trailing @" if token.end_with?("@")
+      errors << "a leading hyphen" if token.start_with?("-")
+      errors << "a trailing hyphen" if token.end_with?("-")
+
+      errors << "multiple @ symbols" if token.count("@") > 1
+
+      errors << "a hyphen followed by an @" if token.include? "-@"
+      errors << "an @ followed by a hyphen" if token.include? "@-"
+
+      errors
+    end
+  end
+end