[NO TICKET] test code coverage with symlinked dependency required via entrypoint

Rakefile

@@ -103,7 +103,7 @@ namespace :test do
           "bundle exec appraisal #{ruby_runtime}-#{appraisal_group} rake #{spec_task}"
         end
 
-        command += "'[#{spec_arguments}]'" if spec_arguments
+        command = "#{command} '[#{spec_arguments}]'" if spec_arguments
 
         total_executors = ENV.key?("CIRCLE_NODE_TOTAL") ? ENV["CIRCLE_NODE_TOTAL"].to_i : nil
         current_executor = ENV.key?("CIRCLE_NODE_INDEX") ? ENV["CIRCLE_NODE_INDEX"].to_i : nil
@@ -133,18 +133,17 @@ namespace :spec do
   end
 
   # Datadog CI integrations
-  [
-    :cucumber,
-    :rspec,
-    :minitest,
-    :minitest_shoulda_context,
-    :activesupport,
-    :ci_queue_minitest,
-    :ci_queue_rspec,
-    :knapsack_rspec,
-    :knapsack_rspec_go,
-    :selenium,
-    :timecop
+  %i[
+    cucumber
+    rspec
+    minitest
+    minitest_shoulda_context
+    activesupport
+    ci_queue_minitest
+    ci_queue_rspec
+    knapsack_rspec
+    knapsack_rspec_go
+    selenium timecop
   ].each do |contrib|
     desc "" # "Explicitly hiding from `rake -T`"
     RSpec::Core::RakeTask.new(contrib) do |t, args|

spec/ddcov/calculator_with_symlinks/calculator.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+require_relative "vendor/gems/operations/operations"
+
+class Calculator
+  def initialize
+    @adder = Add.new
+    @subtractor = Subtract.new
+    @multiplier = Multiply.new
+    @divider = Divide.new
+  end
+
+  def add(a, b)
+    @adder.call(a, b)
+  end
+
+  def subtract(a, b)
+    @subtractor.call(a, b)
+  end
+
+  def multiply(a, b)
+    @multiplier.call(a, b)
+  end
+
+  def divide(a, b)
+    @divider.call(a, b)
+  end
+end

spec/ddcov/calculator_with_symlinks/operations/add.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class Add
+  def call(a, b)
+    a + b
+  end
+end

spec/ddcov/calculator_with_symlinks/operations/divide.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+require_relative "helpers/calculator_logger"
+
+class Divide
+  prepend CalculatorLogger
+
+  def call(a, b)
+    a / b
+  end
+end

spec/ddcov/calculator_with_symlinks/operations/helpers/calculator_logger.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+module CalculatorLogger
+  def call(a, b)
+    res = super
+
+    @log ||= []
+    @log << "operation performed"
+
+    res
+  end
+end

spec/ddcov/calculator_with_symlinks/operations/multiply.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class Multiply
+  def call(a, b)
+    a * b
+  end
+end

spec/ddcov/calculator_with_symlinks/operations/operations.rb

@@ -0,0 +1,4 @@
+require_relative "add"
+require_relative "divide"
+require_relative "multiply"
+require_relative "subtract"

spec/ddcov/calculator_with_symlinks/operations/subtract.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class Subtract
+  def call(a, b)
+    a - b
+  end
+end

spec/ddcov/ddcov_with_symlinks_spec.rb

@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+require "fileutils"
+
+require "datadog_cov.#{RUBY_VERSION}_#{RUBY_PLATFORM}"
+
+RSpec.describe Datadog::CI::ITR::Coverage::DDCov do
+  def absolute_path(path)
+    File.expand_path(File.join(__dir__, path))
+  end
+
+  before do
+    # create a symlink to the calculator_with_symlinks/operations folder in vendor/gems
+    FileUtils.ln_s(
+      absolute_path("calculator_with_symlinks/operations"),
+      absolute_path("calculator_with_symlinks/vendor/gems/operations"),
+      force: true
+    )
+
+    require_relative "calculator_with_symlinks/calculator"
+  end
+
+  after do
+    # delete symlink
+    FileUtils.rm_f(
+      absolute_path("calculator_with_symlinks/vendor/gems/operations")
+    )
+  end
+
+  subject { described_class.new(root: root) }
+
+  describe "code coverage collection" do
+    let!(:calculator) { Calculator.new }
+
+    context "when root is the calculator project dir" do
+      let(:root) { absolute_path("calculator_with_symlinks") }
+
+      it "collects code coverage including Calculator and operations" do
+        subject.start
+
+        expect(calculator.add(1, 2)).to eq(3)
+        expect(calculator.subtract(1, 2)).to eq(-1)
+
+        coverage = subject.stop
+
+        expect(coverage.size).to eq(3)
+        expect(coverage.keys).to include(
+          absolute_path("calculator_with_symlinks/calculator.rb"),
+          absolute_path("calculator_with_symlinks/operations/add.rb"),
+          absolute_path("calculator_with_symlinks/operations/subtract.rb")
+        )
+      end
+    end
+  end
+end