Taps: cleanup regexps around Taps

Closes Homebrew/homebrew#29139.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Library/Homebrew/cmd/tap.rb

@@ -107,7 +107,7 @@ module Homebrew extend self
   end
 
   def tap_args
-    ARGV.first =~ %r{^([\w-]+)/(homebrew-)?([\w-]+)$}
+    ARGV.first =~ HOMEBREW_TAP_ARGS_REGEX
     raise "Invalid tap name" unless $1 && $3
     [$1, $3]
   end
@@ -122,7 +122,7 @@ module Homebrew extend self
 
   def tap_ref(path)
     case path.to_s
-    when %r{^#{HOMEBREW_LIBRARY}/Taps/([\w-]+)/([\w-]+)/(.+)}
+    when HOMEBREW_TAP_PATH_REGEX
       "#$1/#$2/#{File.basename($3, '.rb')}"
     when %r{^#{HOMEBREW_LIBRARY}/Formula/(.+)}
       "Homebrew/homebrew/#{File.basename($1, '.rb')}"

Library/Homebrew/cmd/update.rb

@@ -218,9 +218,9 @@ class Report < Hash
 
   def tapped_formula_for key
     fetch(key, []).select do |path|
-      case path.relative_path_from(HOMEBREW_REPOSITORY).to_s
-      when %r{^Library/Taps/([\w-]+/[\w-]+/.*)}
-        valid_formula_location?($1)
+      case path.to_s
+      when HOMEBREW_TAP_PATH_REGEX
+        valid_formula_location?("#{$1}/#{$2}/#{$3}")
       else
         false
       end
@@ -247,11 +247,11 @@ class Report < Hash
 
   def select_formula key
     fetch(key, []).map do |path|
-      case path.relative_path_from(HOMEBREW_REPOSITORY).to_s
-      when %r{^Library/Formula}
+      case path.to_s
+      when Regexp.new(HOMEBREW_LIBRARY + "/Formula")
         path.basename(".rb").to_s
-      when %r{^Library/Taps/([\w-]+)/(homebrew-)?([\w-]+)/(.*)\.rb}
-        "#$1/#$3/#{path.basename(".rb")}"
+      when HOMEBREW_TAP_PATH_REGEX
+        "#$1/#{$2.sub("homebrew-", "")}/#{path.basename(".rb")}"
       end
     end.compact.sort
   end

Library/Homebrew/global.rb

@@ -85,10 +85,7 @@ HOMEBREW_USER_AGENT = "Homebrew #{HOMEBREW_VERSION} (Ruby #{RUBY_VERSION}-#{RUBY
 
 HOMEBREW_CURL_ARGS = '-f#LA'
 
-HOMEBREW_TAP_FORMULA_REGEX = %r{^([\w-]+)/([\w-]+)/([\w-]+)$}
-HOMEBREW_TAP_DIR_REGEX = %r{#{HOMEBREW_LIBRARY}/Taps/([\w-]+)/([\w-]+)}
-HOMEBREW_TAP_PATH_REGEX = Regexp.new(HOMEBREW_TAP_DIR_REGEX.source \
-                                     + %r{/(.*)}.source)
+require 'tap_constants'
 
 module Homebrew extend self
   include FileUtils

Library/Homebrew/tap_constants.rb

@@ -0,0 +1,8 @@
+# match expressions when taps are given as ARGS, e.g. someuser/sometap
+HOMEBREW_TAP_ARGS_REGEX = %r{^([\w-]+)/(homebrew-)?([\w-]+)$}
+# match taps' formula, e.g. someuser/sometap/someformula
+HOMEBREW_TAP_FORMULA_REGEX = %r{^([\w-]+)/([\w-]+)/([\w-]+)$}
+# match taps' directory path, e.g. HOMEBREW_LIBRARY/Taps/someuser/sometap
+HOMEBREW_TAP_DIR_REGEX = %r{#{HOMEBREW_LIBRARY}/Taps/([\w-]+)/([\w-]+)}
+# match taps' formula path, e.g. HOMEBREW_LIBRARY/Taps/someuser/sometap/someformula
+HOMEBREW_TAP_PATH_REGEX = Regexp.new(HOMEBREW_TAP_DIR_REGEX.source + %r{/(.*)}.source)

Library/Homebrew/test/testing_env.rb

@@ -27,7 +27,7 @@ HOMEBREW_WWW           = 'http://example.com'
 HOMEBREW_CURL_ARGS     = '-fsLA'
 HOMEBREW_VERSION       = '0.9-test'
 
-HOMEBREW_TAP_FORMULA_REGEX = %r{^([\w-]+)/([\w-]+)/([\w-]+)$}
+require 'tap_constants'
 
 RUBY_BIN = Pathname.new(RbConfig::CONFIG['bindir'])
 RUBY_PATH = RUBY_BIN + RbConfig::CONFIG['ruby_install_name'] + RbConfig::CONFIG['EXEEXT']