Add test:valgrind rake task and use it in CI

.github/workflows/ci.yml

@@ -13,3 +13,14 @@ jobs:
         ruby-version: 2.7
         bundler-cache: true
     - run: bundle exec rake
+
+  valgrind:
+    runs-on: ubuntu-latest
+    steps:
+    - run: sudo apt-get install -y valgrind
+    - uses: actions/checkout@v2
+    - uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: 2.7
+        bundler-cache: true
+    - run: bundle exec rake test:valgrind

Gemfile

@@ -5,3 +5,4 @@ gemspec
 
 gem "rubocop", "~> 1.22", require: false
 gem "rubocop-shopify", "~> 2.3.0", require: false
+gem "ruby_memcheck", require: false

Rakefile

@@ -31,10 +31,24 @@ end
 # ==========================================================
 
 require "rake/testtask"
-Rake::TestTask.new("test") do |t|
+require "ruby_memcheck"
+
+RubyMemcheck.config(
+  binary_name: "rotoscope",
+  skipped_ruby_functions: RubyMemcheck::Configuration::DEFAULT_SKIPPED_RUBY_FUNCTIONS + [
+    /\Arb_tracepoint_new\z/, # TODO: Fix this upstream ruby bug
+  ],
+)
+
+test_config = lambda do |t|
   t.test_files = FileList["test/*_test.rb"]
 end
-task(test: :build)
+
+Rake::TestTask.new(test: :build, &test_config)
+
+namespace :test do
+  RubyMemcheck::TestTask.new(valgrind: :build, &test_config)
+end
 
 task :rubocop do
   require "rubocop/rake_task"

dev.yml

@@ -5,7 +5,7 @@ env:
   ROTOSCOPE_COMPILE_ERROR: '1'
 
 up:
-  - ruby: 2.5.3
+  - ruby: 2.7.4
   - homebrew:
     - clang-format
   - bundler

test/rotoscope_test.rb

@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+at_exit { GC.start } # to reduce false positives in the test:valgrind rake task
+
 $LOAD_PATH.unshift(File.expand_path("../../lib", __FILE__))
 $LOAD_PATH.unshift(File.expand_path("../", __FILE__))
 require "rotoscope"