2 files changed, 81 insertions, 7 deletions

diff --git a/Library/Homebrew/cmd/commands.rb b/Library/Homebrew/cmd/commands.rb
index 6630e7134..88290a43d 100644
--- a/Library/Homebrew/cmd/commands.rb
+++ b/Library/Homebrew/cmd/commands.rb
@@ -27,18 +27,30 @@ module Homebrew
   end
 
   def internal_commands
-    (HOMEBREW_LIBRARY_PATH/"cmd").children.select(&:file?).map { |f| f.basename(".rb").to_s }
+    find_internal_commands HOMEBREW_LIBRARY_PATH/"cmd"
   end
 
   def internal_development_commands
-    (HOMEBREW_LIBRARY_PATH/"dev-cmd").children.select(&:file?).map { |f| f.basename(".rb").to_s }
+    find_internal_commands HOMEBREW_LIBRARY_PATH/"dev-cmd"
   end
 
   def external_commands
-    paths.flat_map { |p| Dir["#{p}/brew-*"] }.
-      select { |f| File.executable?(f) }.
-      map { |f| File.basename(f, ".rb")[5..-1] }.
-      reject { |f| f =~ /\./ }.
-      sort
+    paths.reduce([]) do |cmds, path|
+      Dir["#{path}/brew-*"].each do |file|
+        next unless File.executable?(file)
+        cmd = File.basename(file, ".rb")[5..-1]
+        cmds << cmd unless cmd.include?(".")
+      end
+      cmds
+    end.sort
+  end
+
+  private
+
+  def find_internal_commands(directory)
+    directory.children.reduce([]) do |cmds, f|
+      cmds << f.basename.to_s.sub(/\.(?:rb|sh)$/, "") if f.file?
+      cmds
+    end
   end
 end
diff --git a/Library/Homebrew/test/test_commands.rb b/Library/Homebrew/test/test_commands.rb
new file mode 100644
index 000000000..0fb46dd9c
--- /dev/null
+++ b/Library/Homebrew/test/test_commands.rb
@@ -0,0 +1,62 @@
+require "testing_env"
+require "cmd/commands"
+require "fileutils"
+
+class CommandsCommandTests < Homebrew::TestCase
+  def setup
+    @cmds = [
+      # internal commands
+      HOMEBREW_LIBRARY_PATH/"cmd/rbcmd.rb",
+      HOMEBREW_LIBRARY_PATH/"cmd/shcmd.sh",
+
+      # internal development commands
+      HOMEBREW_LIBRARY_PATH/"dev-cmd/rbdevcmd.rb",
+      HOMEBREW_LIBRARY_PATH/"dev-cmd/shdevcmd.sh",
+    ]
+
+    @cmds.each { |f| FileUtils.touch f }
+  end
+
+  def teardown
+    @cmds.each { |f| f.unlink }
+  end
+
+  def test_internal_commands
+    cmds = Homebrew.internal_commands
+    assert cmds.include?("rbcmd"), "Ruby commands files should be recognized"
+    assert cmds.include?("shcmd"), "Shell commands files should be recognized"
+    refute cmds.include?("rbdevcmd"), "Dev commands shouldn't be included"
+  end
+
+  def test_internal_development_commands
+    cmds = Homebrew.internal_development_commands
+    assert cmds.include?("rbdevcmd"), "Ruby commands files should be recognized"
+    assert cmds.include?("shdevcmd"), "Shell commands files should be recognized"
+    refute cmds.include?("rbcmd"), "Non-dev commands shouldn't be included"
+  end
+
+  def test_external_commands
+    env = ENV.to_hash
+
+    mktmpdir do |dir|
+      %w[brew-t1 brew-t2.rb brew-t3.py].each do |file|
+        path = "#{dir}/#{file}"
+        FileUtils.touch path
+        FileUtils.chmod 0744, path
+      end
+
+      FileUtils.touch "#{dir}/t4"
+
+      ENV["PATH"] = "#{ENV["PATH"]}#{File::PATH_SEPARATOR}#{dir}"
+      cmds = Homebrew.external_commands
+
+      assert cmds.include?("t1"), "Executable files should be included"
+      assert cmds.include?("t2"), "Executable Ruby files should be included"
+      refute cmds.include?("t3"),
+        "Executable files with a non Ruby extension shoudn't be included"
+      refute cmds.include?("t4"), "Non-executable files shouldn't be included"
+    end
+  ensure
+    ENV.replace(env)
+  end
+end