set JETBRAINS_DPA_AGENT_ENABLE by default to 0 to disable ReSharper's Dynamic Program Analysis, fixes #1871 (#1874)

Author: adamsitnik

src/BenchmarkDotNet/Extensions/ProcessExtensions.cs

@@ -126,6 +126,9 @@ internal static void SetEnvironmentVariables(this ProcessStartInfo start, Benchm
             if (benchmarkCase.Job.Infrastructure.Toolchain is CoreRunToolchain _)
                 start.SetCoreRunEnvironmentVariables(benchmarkCase, resolver);
 
+            // disable ReSharper's Dynamic Program Analysis (see https://github.com/dotnet/BenchmarkDotNet/issues/1871 for details)
+            start.EnvironmentVariables["JETBRAINS_DPA_AGENT_ENABLE"] = "0";
+
             if (!benchmarkCase.Job.HasValue(EnvironmentMode.EnvironmentVariablesCharacteristic))
                 return;
 

tests/BenchmarkDotNet.IntegrationTests/EnvironmentVariablesTests.cs

@@ -34,5 +34,39 @@ public void Benchmark()
                     throw new InvalidOperationException("The env var was not set");
             }
         }
+
+        [Fact]
+        public void ResharperDynamicProgramAnalysisIsDisabledByDefault()
+            => CanExecute<TestingDpaDisabled>(CreateSimpleConfig(job: Job.Dry));
+
+        public class TestingDpaDisabled
+        {
+            [Benchmark]
+            public void Benchmark()
+            {
+                if (Environment.GetEnvironmentVariable("JETBRAINS_DPA_AGENT_ENABLE") != "0")
+                    throw new InvalidOperationException("The JETBRAINS_DPA_AGENT_ENABLE env var was not set to zero");
+            }
+        }
+
+        [Fact]
+        public void ResharperDynamicProgramAnalysisCanBeEnabled()
+        {
+            var jobWithSettingEnabled = Job.Dry.WithEnvironmentVariable("JETBRAINS_DPA_AGENT_ENABLE", "1");
+            var config = CreateSimpleConfig(job: jobWithSettingEnabled);
+
+            CanExecute<TestingDpaEnabled>(config);
+        }
+
+        public class TestingDpaEnabled
+        {
+            [Benchmark]
+            public void Benchmark()
+            {
+                if (Environment.GetEnvironmentVariable("JETBRAINS_DPA_AGENT_ENABLE") != "1")
+                    throw new InvalidOperationException("The JETBRAINS_DPA_AGENT_ENABLE env var was not set to one");
+            }
+        }
+
     }
 }