Do less work inside chdir blocks

Library/Homebrew/test/test_pathname.rb

@@ -96,100 +96,95 @@ class PathnameExtensionTests < Homebrew::TestCase
   end
 
   def setup_install_test
-    cd @src do
+    (@src+'a.txt').write 'This is sample file a.'
-      (@src+'a.txt').write 'This is sample file a.'
+    (@src+'b.txt').write 'This is sample file b.'
-      (@src+'b.txt').write 'This is sample file b.'
+    cd(@src) { yield }
-      yield
-    end
   end
 
   def test_install
     setup_install_test do
       @dst.install 'a.txt'
-
-      assert_predicate @dst+"a.txt", :exist?, "a.txt was not installed"
-      refute_predicate @dst+"b.txt", :exist?, "b.txt was installed."
     end
+
+    assert_predicate @dst+"a.txt", :exist?, "a.txt was not installed"
+    refute_predicate @dst+"b.txt", :exist?, "b.txt was installed."
   end
 
   def test_install_list
     setup_install_test do
       @dst.install %w[a.txt b.txt]
-
-      assert_predicate @dst+"a.txt", :exist?, "a.txt was not installed"
-      assert_predicate @dst+"b.txt", :exist?, "b.txt was not installed"
     end
+
+    assert_predicate @dst+"a.txt", :exist?, "a.txt was not installed"
+    assert_predicate @dst+"b.txt", :exist?, "b.txt was not installed"
   end
 
   def test_install_glob
     setup_install_test do
       @dst.install Dir['*.txt']
-
-      assert_predicate @dst+"a.txt", :exist?, "a.txt was not installed"
-      assert_predicate @dst+"b.txt", :exist?, "b.txt was not installed"
     end
+
+    assert_predicate @dst+"a.txt", :exist?, "a.txt was not installed"
+    assert_predicate @dst+"b.txt", :exist?, "b.txt was not installed"
   end
 
   def test_install_directory
     setup_install_test do
       mkdir_p 'bin'
       mv Dir['*.txt'], 'bin'
-
       @dst.install 'bin'
-
-      assert_predicate @dst+"bin/a.txt", :exist?, "a.txt was not installed"
-      assert_predicate @dst+"bin/b.txt", :exist?, "b.txt was not installed"
     end
+
+    assert_predicate @dst+"bin/a.txt", :exist?, "a.txt was not installed"
+    assert_predicate @dst+"bin/b.txt", :exist?, "b.txt was not installed"
   end
 
   def test_install_rename
     setup_install_test do
       @dst.install 'a.txt' => 'c.txt'
-
-      assert_predicate @dst+"c.txt", :exist?, "c.txt was not installed"
-      refute_predicate @dst+"a.txt", :exist?, "a.txt was installed but not renamed"
-      refute_predicate @dst+"b.txt", :exist?, "b.txt was installed"
     end
+
+    assert_predicate @dst+"c.txt", :exist?, "c.txt was not installed"
+    refute_predicate @dst+"a.txt", :exist?, "a.txt was installed but not renamed"
+    refute_predicate @dst+"b.txt", :exist?, "b.txt was installed"
   end
 
   def test_install_rename_more
     setup_install_test do
       @dst.install({'a.txt' => 'c.txt', 'b.txt' => 'd.txt'})
-
-      assert_predicate @dst+"c.txt", :exist?, "c.txt was not installed"
-      assert_predicate @dst+"d.txt", :exist?, "d.txt was not installed"
-      refute_predicate @dst+"a.txt", :exist?, "a.txt was installed but not renamed"
-      refute_predicate @dst+"b.txt", :exist?, "b.txt was installed but not renamed"
     end
+
+    assert_predicate @dst+"c.txt", :exist?, "c.txt was not installed"
+    assert_predicate @dst+"d.txt", :exist?, "d.txt was not installed"
+    refute_predicate @dst+"a.txt", :exist?, "a.txt was installed but not renamed"
+    refute_predicate @dst+"b.txt", :exist?, "b.txt was installed but not renamed"
   end
 
   def test_install_rename_directory
     setup_install_test do
       mkdir_p 'bin'
       mv Dir['*.txt'], 'bin'
-
       @dst.install 'bin' => 'libexec'
-
-      refute_predicate @dst+"bin", :exist?, "bin was installed but not renamed"
-      assert_predicate @dst+"libexec/a.txt", :exist?, "a.txt was not installed"
-      assert_predicate @dst+"libexec/b.txt", :exist?, "b.txt was not installed"
     end
+
+    refute_predicate @dst+"bin", :exist?, "bin was installed but not renamed"
+    assert_predicate @dst+"libexec/a.txt", :exist?, "a.txt was not installed"
+    assert_predicate @dst+"libexec/b.txt", :exist?, "b.txt was not installed"
   end
 
   def test_install_symlink
     setup_install_test do
       mkdir_p 'bin'
       mv Dir['*.txt'], 'bin'
-
-      @dst.install_symlink @src+'bin'
-
-      assert_predicate @dst+"bin", :symlink?
-      assert_predicate @dst+"bin", :directory?
-      assert_predicate @dst+"bin/a.txt", :exist?
-      assert_predicate @dst+"bin/b.txt", :exist?
-
-      assert_predicate (@dst+"bin").readlink, :relative?
     end
+
+    @dst.install_symlink @src+'bin'
+
+    assert_predicate @dst+"bin", :symlink?
+    assert_predicate @dst+"bin", :directory?
+    assert_predicate @dst+"bin/a.txt", :exist?
+    assert_predicate @dst+"bin/b.txt", :exist?
+    assert_predicate (@dst+"bin").readlink, :relative?
   end
 
   def test_install_creates_intermediate_directories