Loading minitest without initializing the plugin should work

lib/minitest/buildkite_collector_plugin.rb

@@ -1,6 +1,6 @@
 module Minitest
   def self.plugin_buildkite_collector_init(options)
-    if Buildkite::TestCollector.respond_to?(:uploader)
+    if defined?(Buildkite::TestCollector::MinitestPlugin) && Buildkite::TestCollector.respond_to?(:uploader)
       self.reporter << Buildkite::TestCollector::MinitestPlugin::Reporter.new(options[:io], options)
     end
   end

spec/test_collector/minitest_plugin/without_plugin_spec.rb

@@ -0,0 +1,9 @@
+require "minitest"
+
+RSpec.describe "don’t break minitest when the plugin isn’t loaded" do
+  describe "running minitest" do
+    it "should not raise an error" do
+      expect { Minitest.run }.not_to raise_error
+    end
+  end
+end