DI: make a test method longer to avoid flakiness (#5069)

Author: p-datadog

spec/datadog/di/integration/instrumentation_spec.rb

@@ -20,6 +20,13 @@ def test_method(a = 1)
     42
   end
 
+  def long_test_method
+    # This method is used to assert on @duration, and +test_method+
+    # somehow managed to report an execution time of 0.0 in CI one time
+    # (though normally it takes about 1 microsecond).
+    Object.methods.length > 0 and 42
+  end
+
   def mutating_method(greeting)
     greeting.sub!('hello', 'bye')
   end
@@ -520,6 +527,15 @@ def run_test
             ]
           end
 
+          let(:probe_spec) do
+            {
+              id: '1234',
+              type: 'LOG_PROBE',
+              where: {typeName: 'InstrumentationSpecTestClass', methodName: 'long_test_method'},
+              segments: segments,
+            }
+          end
+
           it 'substitutes the expected value' do
             probe_manager.add_probe(probe)
 
@@ -535,7 +551,7 @@ def run_test
               expect(value).to be > 0
               expect(value).to be < 1
             end
-            expect(InstrumentationSpecTestClass.new.test_method).to eq(42)
+            expect(InstrumentationSpecTestClass.new.long_test_method).to eq(42)
             component.probe_notifier_worker.flush
           end
         end