spec/spec_helper.rb in nanoc-4.7.11 vs spec/spec_helper.rb in nanoc-4.7.12

@@ -275,5 +275,44 @@
 
   failure_message_when_negated do |_actual|
     "expected that proc would not send notification #{name.inspect} with args #{expected_args.inspect}"
   end
 end
+
+RSpec::Matchers.define :leak_open_files do |_name, *_expected_args|
+  # Some remarks:
+  #
+  # • This matcher relies on global state (list of file descriptors and their
+  #   state), which means that a test case that uses this matcher can fail if
+  #   tests are being run in parallel.
+  #
+  # • This matcher assumes that file descriptors are closed explicitly, rather
+  #   than implicitly through garbage collection. This means that a test case
+  #   that uses this matcher can fail if the code exercised by the test case
+  #   relies on file descriptors to be closed when they are garbage collected.
+
+  supports_block_expectations
+
+  match do |actual|
+    open_files_before = []
+    ObjectSpace.each_object(File) { |f| open_files_before << f.fileno unless f.closed? }
+
+    actual.call
+
+    open_files_after = []
+    ObjectSpace.each_object(File) { |f| open_files_after << f.fileno unless f.closed? }
+
+    open_files_before.sort != open_files_after.sort
+  end
+
+  description do
+    'leak open files'
+  end
+
+  failure_message do |_actual|
+    'expected that proc would leak open files'
+  end
+
+  failure_message_when_negated do |_actual|
+    'expected that proc would not leak open files'
+  end
+end