test_utils: add test_which_all

Library/Homebrew/test/test_utils.rb

@@ -42,6 +42,20 @@ class UtilTests < Homebrew::TestCase
       which(File.basename(cmd), "~~#{File::PATH_SEPARATOR}#{File.dirname(cmd)}")
   end
 
+  def test_which_all
+    (@dir/"bar/baz").mkpath
+    cmd1 = @dir/"foo"
+    cmd2 = @dir/"bar/foo"
+    cmd3 = @dir/"bar/baz/foo"
+    FileUtils.touch cmd2
+    [cmd1, cmd3].each do |cmd|
+      FileUtils.touch cmd
+      cmd.chmod 0744
+    end
+    assert_equal [cmd3, cmd1],
+      which_all("foo", "#{@dir}/bar/baz:#{@dir}/baz:#{@dir}:~baduserpath")
+  end
+
   def test_popen_read
     out = Utils.popen_read("/bin/sh", "-c", "echo success").chomp
     assert_equal "success", out