ensure that integration works for Minitest::Spec

.standard_todo.yml

@@ -2,6 +2,8 @@
 # Remove from this list as you refactor files.
 ---
 ignore:
+- lib/datadog/ci/contrib/minitest/integration.rb:
+  - Style/SafeNavigation
 - lib/datadog/ci/contrib/cucumber/integration.rb:
   - Style/SafeNavigation
 - lib/datadog/ci/contrib/rspec/integration.rb:

lib/datadog/ci/contrib/minitest/integration.rb

@@ -14,7 +14,7 @@ class Integration
           register_as :minitest, auto_patch: true
 
           def self.version
-            Gem.loaded_specs["minitest"]&.version
+            Gem.loaded_specs["minitest"] && Gem.loaded_specs["minitest"].version
           end
 
           def self.loaded?

spec/datadog/ci/contrib/minitest/instrumentation_spec.rb

@@ -1,11 +1,16 @@
 require "time"
+require "minitest"
+require "minitest/spec"
 
 require_relative "../support/spec_helper"
 
 RSpec.describe "Minitest hooks" do
   include_context "CI mode activated"
 
   before do
+    # required to call .runnable_methods
+    Minitest.seed = 1
+
     Datadog.configure do |c|
       c.ci.instrument :minitest, service_name: "ltest"
     end
@@ -60,6 +65,49 @@ def self.name
     expect(spans).to have(num_tests).items
   end
 
+  it "creates span for spec" do
+    klass = Class.new(Minitest::Spec) do
+      def self.name
+        "SomeSpec"
+      end
+
+      it "does not fail" do
+      end
+    end
+
+    method_name = klass.runnable_methods.first
+    klass.new(method_name).run
+
+    expect(span.span_type).to eq(Datadog::CI::Ext::AppTypes::TYPE_TEST)
+    expect(span.resource).to eq("SomeSpec##{method_name}")
+    expect(span.service).to eq("ltest")
+    expect(span.get_tag(Datadog::CI::Ext::Test::TAG_NAME)).to eq("SomeSpec##{method_name}")
+    expect(span.get_tag(Datadog::CI::Ext::Test::TAG_SUITE)).to eq(
+      "spec/datadog/ci/contrib/minitest/instrumentation_spec.rb"
+    )
+  end
+
+  it "creates spans for several specs" do
+    num_specs = 20
+
+    klass = Class.new(Minitest::Spec) do
+      def self.name
+        "SomeSpec"
+      end
+
+      num_specs.times do |i|
+        it "does fail #{}" do
+        end
+      end
+    end
+
+    klass.runnable_methods.each do |method_name|
+      klass.new(method_name).run
+    end
+
+    expect(spans).to have(num_specs).items
+  end
+
   it "creates spans for example with instrumentation" do
     klass = Class.new(Minitest::Test) do
       def self.name