test_integration_cmds: basic integration tests.

Closes Homebrew/homebrew#41945.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Library/Homebrew/test/test_integration_cmds.rb

@@ -0,0 +1,81 @@
+require "testing_env"
+
+class IntegrationCommandTests < Homebrew::TestCase
+  def cmd_output *args
+    cmd_args = %W[
+     -W0
+     -I#{HOMEBREW_LIBRARY_PATH}/test/lib
+     -rconfig
+    ]
+    cmd_args << "-rsimplecov" if ENV["HOMEBREW_TESTS_COVERAGE"]
+    cmd_args << (HOMEBREW_LIBRARY_PATH/"../brew.rb").resolved_path.to_s
+    cmd_args += args
+    Bundler.with_original_env do
+      ENV["HOMEBREW_BREW_FILE"] = HOMEBREW_PREFIX/"bin/brew"
+      ENV["HOMEBREW_INTEGRATION_TEST"] = args.join " "
+      ENV["HOMEBREW_TEST_TMPDIR"] = TEST_TMPDIR
+      Utils.popen_read(RUBY_PATH, *cmd_args).chomp
+    end
+  end
+
+  def cmd *args
+    output = cmd_output(*args)
+    assert_equal 0, $?.exitstatus
+    output
+  end
+
+  def cmd_fail *args
+    output = cmd_output(*args)
+    assert_equal 1, $?.exitstatus
+    output
+  end
+
+  def testball
+    "#{File.expand_path("..", __FILE__)}/testball.rb"
+  end
+
+  def test_prefix
+    assert_equal HOMEBREW_PREFIX.to_s,
+                 cmd("--prefix")
+  end
+
+  def test_version
+    assert_equal HOMEBREW_VERSION.to_s,
+                 cmd("--version")
+  end
+
+  def test_cache
+    assert_equal HOMEBREW_CACHE.to_s,
+                 cmd("--cache")
+  end
+
+  def test_cache_formula
+    assert_match %r{#{HOMEBREW_CACHE}/testball-},
+                 cmd("--cache", testball)
+  end
+
+  def test_cellar
+    assert_equal HOMEBREW_CELLAR.to_s,
+                 cmd("--cellar")
+  end
+
+  def test_cellar_formula
+    assert_match "#{HOMEBREW_CELLAR}/testball",
+                 cmd("--cellar", testball)
+  end
+
+  def test_env
+    assert_match "CMAKE_PREFIX_PATH=\"#{HOMEBREW_PREFIX}\"",
+                 cmd("--env")
+  end
+
+  def test_prefix_formula
+    assert_match "#{HOMEBREW_CELLAR}/testball",
+                 cmd("--prefix", testball)
+  end
+
+  def test_repository
+    assert_match HOMEBREW_REPOSITORY.to_s,
+                 cmd("--repository")
+  end
+end