Add teardown cleanup to all test files to prevent resource exhaustion

The Ruby 3.4 CI hang was caused by zombie Node.js processes accumulating
across test runs. When processes aren't properly closed, fork() can block
due to resource exhaustion.

This commit adds teardown methods to:
- schmooze_test.rb
- error_test.rb
- garbage_test.rb
- local_script_test.rb

Each teardown calls close() on the schmoozer instance if it has a running
process, ensuring Node.js processes are properly terminated after each test.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: koji-takao-sp

test/error_test.rb

@@ -4,6 +4,16 @@
 class ErrorTest < Minitest::Test
   FIXTURES_DIR = File.join(__dir__, 'fixtures')
 
+  def setup
+    @schmoozer = nil
+  end
+
+  def teardown
+    if @schmoozer&.pid
+      @schmoozer.close rescue nil
+    end
+  end
+
   class ErrorSchmoozer < Schmooze::Base
     dependencies nonexistant: 'this-package-is-not-here'
     method :bogus, 'bogus'
@@ -54,8 +64,9 @@ def test_import_error_but_in_package_json
 
   def test_javascript_error
     dir = File.join(FIXTURES_DIR, 'coffee')
+    @schmoozer = CoffeeSchmoozer.new(dir)
     error = assert_raises Schmooze::JavaScript::SyntaxError do
-      CoffeeSchmoozer.new(dir).compile('<=> 1')
+      @schmoozer.compile('<=> 1')
     end
 
     assert_equal <<-ERROR.strip, error.message
@@ -67,27 +78,28 @@ def test_javascript_error
 
   def test_late_arriving_dependency
     dir = File.join(FIXTURES_DIR, 'late-dep')
-    late = LateArrivingDependency.new(dir, {"NODE_PATH" => dir})
+    @schmoozer = LateArrivingDependency.new(dir, {"NODE_PATH" => dir})
 
     assert_raises Schmooze::DependencyError do
-      late.test
+      @schmoozer.test
     end
 
     assert_raises Schmooze::DependencyError do
-      late.test
+      @schmoozer.test
     end
 
     File.write(File.join(dir, 'empty.js'), 'module.exports = null;')
 
-    assert_equal late.test, 1
+    assert_equal @schmoozer.test, 1
   ensure
     FileUtils.rm(File.join(dir, 'empty.js'), force: true)
   end
 
   def test_unknown_error
     dir = File.join(FIXTURES_DIR, 'coffee')
+    @schmoozer = UnknownErrorSchmoozer.new(dir)
     error = assert_raises Schmooze::JavaScript::UnknownError do
-      UnknownErrorSchmoozer.new(dir).throw_string
+      @schmoozer.throw_string
     end
     assert_equal '¯\_(ツ)_/¯', error.message
   end

test/garbage_test.rb

@@ -5,11 +5,21 @@ class GarbageSchmoozer < Schmooze::Base
     method :test, 'function(){ return 1; }'
   end
 
+  def setup
+    @schmoozer = nil
+  end
+
+  def teardown
+    if @schmoozer&.pid
+      @schmoozer.close rescue nil
+    end
+  end
+
   def test_process_is_not_started_until_used
-    garbage = GarbageSchmoozer.new(__dir__)
-    assert_nil garbage.pid
-    garbage.test
-    assert garbage.pid
+    @schmoozer = GarbageSchmoozer.new(__dir__)
+    assert_nil @schmoozer.pid
+    @schmoozer.test
+    assert @schmoozer.pid
   end
 
   def test_process_is_closed

test/local_script_test.rb

@@ -11,6 +11,12 @@ def setup
     @schmoozer = LocalScriptSchmoozer.new(File.join(__dir__, 'fixtures', 'local_script'))
   end
 
+  def teardown
+    if @schmoozer&.pid
+      @schmoozer.close rescue nil
+    end
+  end
+
   def test_usage
     assert_equal 456, @schmoozer.test
   end

test/schmooze_test.rb

@@ -27,6 +27,12 @@ def setup
     @schmoozer = CoffeeSchmoozer.new(File.join(__dir__, 'fixtures', 'coffee'))
   end
 
+  def teardown
+    if @schmoozer&.pid
+      @schmoozer.close rescue nil
+    end
+  end
+
   def test_that_it_has_a_version_number
     refute_nil ::Schmooze::VERSION
   end