test_integration_cmds: use a single teardown. (#475)

Instead of writing a custom ensure for every test let's just nuke
all the files every time. This may be something we might want to use for
other unit tests too. It leans heavily on the fact that a
`FileUtils.rm_rf` on files that don't exist is very quick and things
like `brew cleanup` are super slow in comparison.

Before:
```
$ brew tests --only=integration_cmds --official-cmd-taps
Finished in 49.764724s, 1.0047 runs/s, 5.2648 assertions/s.
```

After:
```
$ brew tests --only=integration_cmds --official-cmd-taps
Finished in 43.014769s, 1.1624 runs/s, 5.8352 assertions/s.
```

Library/Homebrew/test/test_integration_cmds.rb

@@ -6,15 +6,33 @@ require "formula"
 
 class IntegrationCommandTests < Homebrew::TestCase
   def setup
-    @formula_files = []
     @cmd_id_index = 0 # Assign unique IDs to invocations of `cmd_output`.
     (HOMEBREW_PREFIX/"bin").mkpath
     FileUtils.touch HOMEBREW_PREFIX/"bin/brew"
   end
 
   def teardown
-    (HOMEBREW_PREFIX/"bin").rmtree
+    coretap = CoreTap.new
-    @formula_files.each(&:unlink)
+    paths_to_delete = [
+      HOMEBREW_CELLAR.children,
+      HOMEBREW_CACHE.children,
+      HOMEBREW_LOCK_DIR.children,
+      HOMEBREW_LOGS.children,
+      HOMEBREW_PREFIX/"bin",
+      HOMEBREW_PREFIX/"share",
+      HOMEBREW_PREFIX/"opt",
+      HOMEBREW_LIBRARY/"LinkedKegs",
+      HOMEBREW_LIBRARY/"Taps/caskroom",
+      HOMEBREW_LIBRARY/"Taps/homebrew/homebrew-bundle",
+      HOMEBREW_LIBRARY/"Taps/homebrew/homebrew-foo",
+      HOMEBREW_LIBRARY/"Taps/homebrew/homebrew-services",
+      HOMEBREW_LIBRARY/"Taps/homebrew/homebrew-shallow",
+      HOMEBREW_REPOSITORY/".git",
+      coretap.path/".git",
+      coretap.alias_dir,
+      coretap.formula_dir.children,
+    ].flatten
+    FileUtils.rm_rf paths_to_delete
   end
 
   def needs_test_cmd_taps
@@ -90,7 +108,6 @@ class IntegrationCommandTests < Homebrew::TestCase
 
   def setup_test_formula(name, content = nil)
     formula_path = CoreTap.new.formula_dir/"#{name}.rb"
-    @formula_files << formula_path
 
     case name
     when "testball"
@@ -241,24 +258,16 @@ class IntegrationCommandTests < Homebrew::TestCase
     end
     assert_match(/testball-0\.1.*\.bottle\.tar\.gz/,
                   cmd_output("bottle", "--no-revision", "testball"))
-  ensure
-    cmd("uninstall", "--force", "testball")
-    cmd("cleanup", "--force", "--prune=all")
-    FileUtils.rm_f Dir["testball-0.1*.bottle.tar.gz"]
   end
 
   def test_uninstall
     cmd("install", testball)
     assert_match "Uninstalling testball", cmd("uninstall", "--force", testball)
-  ensure
-    cmd("cleanup", "--force", "--prune=all")
   end
 
   def test_cleanup
     (HOMEBREW_CACHE/"test").write "test"
     assert_match "#{HOMEBREW_CACHE}/test", cmd("cleanup", "--prune=all")
-  ensure
-    FileUtils.rm_f HOMEBREW_CACHE/"test"
   end
 
   def test_readall
@@ -268,8 +277,6 @@ class IntegrationCommandTests < Homebrew::TestCase
     FileUtils.ln_s formula_file, alias_file
     cmd("readall", "--aliases", "--syntax")
     cmd("readall", "homebrew/core")
-  ensure
-    alias_file.parent.rmtree
   end
 
   def test_tap
@@ -297,8 +304,6 @@ class IntegrationCommandTests < Homebrew::TestCase
     assert_match "Untapped", cmd("untap", "homebrew/bar")
     assert_equal "", cmd("tap", "homebrew/bar", path/".git", "-q", "--full")
     assert_match "Untapped", cmd("untap", "homebrew/bar")
-  ensure
-    path.rmtree
   end
 
   def test_missing
@@ -307,8 +312,6 @@ class IntegrationCommandTests < Homebrew::TestCase
 
     (HOMEBREW_CELLAR/"bar/1.0").mkpath
     assert_match "foo", cmd("missing")
-  ensure
-    (HOMEBREW_CELLAR/"bar").rmtree
   end
 
   def test_doctor
@@ -346,8 +349,6 @@ class IntegrationCommandTests < Homebrew::TestCase
 
     cmd("desc", "--description", "testball")
     assert_predicate desc_cache, :exist?, "Cached file should not exist"
-  ensure
-    desc_cache.unlink
   end
 
   def test_edit
@@ -356,8 +357,6 @@ class IntegrationCommandTests < Homebrew::TestCase
 
     assert_match "# something here",
                  cmd("edit", "testball", "HOMEBREW_EDITOR" => "/bin/cat")
-  ensure
-    (HOMEBREW_REPOSITORY/".git").unlink
   end
 
   def test_sh
@@ -377,8 +376,6 @@ class IntegrationCommandTests < Homebrew::TestCase
                  cmd("tap-readme", "foo", "--verbose")
     readme = HOMEBREW_LIBRARY/"Taps/homebrew/homebrew-foo/README.md"
     assert readme.exist?, "The README should be created"
-  ensure
-    (HOMEBREW_LIBRARY/"Taps/homebrew/homebrew-foo").rmtree
   end
 
   def test_unpack
@@ -389,8 +386,6 @@ class IntegrationCommandTests < Homebrew::TestCase
       assert File.directory?("#{path}/testball-0.1"),
         "The tarball should be unpacked"
     end
-  ensure
-    FileUtils.rm_f HOMEBREW_CACHE/"testball-0.1.tbz"
   end
 
   def test_options
@@ -407,8 +402,6 @@ class IntegrationCommandTests < Homebrew::TestCase
     (HOMEBREW_CELLAR/"testball/0.0.1/foo").mkpath
 
     assert_equal "testball", cmd("outdated")
-  ensure
-    FileUtils.rm_rf HOMEBREW_CELLAR/"testball"
   end
 
   def test_upgrade
@@ -418,9 +411,6 @@ class IntegrationCommandTests < Homebrew::TestCase
     cmd("upgrade")
     assert((HOMEBREW_CELLAR/"testball/0.1").directory?,
       "The latest version directory should be created")
-  ensure
-    cmd("uninstall", "--force", testball)
-    cmd("cleanup", "--force", "--prune=all")
   end
 
   def test_linkapps
@@ -433,9 +423,6 @@ class IntegrationCommandTests < Homebrew::TestCase
     source_dir.mkpath
     assert_match "Linking: #{source_dir}",
       cmd("linkapps", "--local", "HOME" => home_dir)
-  ensure
-    home_dir.rmtree
-    (HOMEBREW_CELLAR/"testball").rmtree
   end
 
   def test_unlinkapps
@@ -452,9 +439,6 @@ class IntegrationCommandTests < Homebrew::TestCase
 
     assert_match "Unlinking: #{apps_dir}/TestBall.app",
       cmd("unlinkapps", "--local", "HOME" => home_dir)
-  ensure
-    home_dir.rmtree
-    (HOMEBREW_CELLAR/"testball").rmtree
   end
 
   def test_pin_unpin
@@ -470,9 +454,6 @@ class IntegrationCommandTests < Homebrew::TestCase
     cmd("upgrade")
     assert((HOMEBREW_CELLAR/"testball/0.1").directory?,
       "The latest version directory should be created")
-  ensure
-    cmd("uninstall", "--force", testball)
-    cmd("cleanup", "--force", "--prune=all")
   end
 
   def test_reinstall
@@ -485,9 +466,6 @@ class IntegrationCommandTests < Homebrew::TestCase
     assert_match "Reinstalling testball with --with-foo",
       cmd("reinstall", "testball")
     assert foo_dir.exist?
-  ensure
-    cmd("uninstall", "--force", "testball")
-    cmd("cleanup", "--force", "--prune=all")
   end
 
   def test_home
@@ -507,10 +485,6 @@ class IntegrationCommandTests < Homebrew::TestCase
 
     assert_equal formulae.join("\n"),
                  cmd("list")
-  ensure
-    formulae.each do |f|
-      (HOMEBREW_CELLAR/"#{f}").rmtree
-    end
   end
 
   def test_create
@@ -520,9 +494,6 @@ class IntegrationCommandTests < Homebrew::TestCase
     formula_file = CoreTap.new.formula_dir/"testball.rb"
     assert formula_file.exist?, "The formula source should have been created"
     assert_match %(sha256 "#{TESTBALL_SHA256}"), formula_file.read
-  ensure
-    formula_file.unlink
-    cmd("cleanup", "--force", "--prune=all")
   end
 
   def test_fetch
@@ -531,8 +502,6 @@ class IntegrationCommandTests < Homebrew::TestCase
     cmd("fetch", "testball")
     assert((HOMEBREW_CACHE/"testball-0.1.tbz").exist?,
       "The tarball should have been cached")
-  ensure
-    cmd("cleanup", "--force", "--prune=all")
   end
 
   def test_deps
@@ -569,8 +538,6 @@ class IntegrationCommandTests < Homebrew::TestCase
       end
     end
     assert_match "This is a test commit", cmd("log")
-  ensure
-    (HOMEBREW_REPOSITORY/".git").rmtree
   end
 
   def test_log_formula
@@ -595,9 +562,6 @@ class IntegrationCommandTests < Homebrew::TestCase
                  cmd("log", "#{shallow_tap}/testball")
     assert_predicate shallow_tap.path/".git/shallow", :exist?,
                      "A shallow clone should have been created."
-  ensure
-    (core_tap.path/".git").rmtree
-    shallow_tap.path.rmtree
   end
 
   def test_leaves
@@ -610,9 +574,6 @@ class IntegrationCommandTests < Homebrew::TestCase
 
     (HOMEBREW_CELLAR/"bar/0.1/somedir").mkpath
     assert_equal "bar", cmd("leaves")
-  ensure
-    (HOMEBREW_CELLAR/"foo").rmtree
-    (HOMEBREW_CELLAR/"bar").rmtree
   end
 
   def test_prune
@@ -634,8 +595,6 @@ class IntegrationCommandTests < Homebrew::TestCase
     # more line with contents `No apps unlinked from /Users/<user/Applications`.
     assert_match "Nothing pruned\nNo apps unlinked from /Applications",
       cmd("prune", "--verbose")
-  ensure
-    share.rmtree
   end
 
   def test_custom_command
@@ -676,8 +635,6 @@ class IntegrationCommandTests < Homebrew::TestCase
     end
 
     assert_predicate desc_cache, :exist?, "Cached file should exist"
-  ensure
-    desc_cache.unlink
   end
 
   def test_bundle
@@ -697,18 +654,12 @@ class IntegrationCommandTests < Homebrew::TestCase
           cmd("bundle", "check")
       end
     end
-  ensure
-    FileUtils.rm_rf HOMEBREW_REPOSITORY/".git"
-    FileUtils.rm_rf HOMEBREW_LIBRARY/"Taps/homebrew/homebrew-bundle"
   end
 
   def test_cask
     needs_test_cmd_taps
     setup_remote_tap("caskroom/cask")
     cmd("cask", "list")
-  ensure
-    FileUtils.rm_rf HOMEBREW_LIBRARY/"Taps/caskroom"
-    FileUtils.rm_rf HOMEBREW_PREFIX/"share"
   end
 
   def test_services
@@ -716,7 +667,5 @@ class IntegrationCommandTests < Homebrew::TestCase
     setup_remote_tap("homebrew/services")
     assert_equal "Warning: No services available to control with `brew services`",
       cmd("services", "list")
-  ensure
-    FileUtils.rm_rf HOMEBREW_LIBRARY/"Taps/homebrew/homebrew-services"
   end
 end