test(agentcompat): add exact stress scenario

Co-authored-by: naiba/CloudCode <hi+cloudcode@nai.ba>

integration/agentcompat/internal/scenario/stress_path_lock_test.go

@@ -0,0 +1,35 @@
+//go:build linux && agentcompat
+
+package scenario
+
+import (
+	"crypto/sha256"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestStressPathLockProofRequiresExactStripeCount(t *testing.T) {
+	for _, stripes := range []int{1023, 1025} {
+		require.ErrorIs(t, (stressPathLockProof{Stripes: stripes}).Validate(), ErrStressPathLockProof)
+	}
+	require.NoError(t, (stressPathLockProof{Stripes: 1024}).Validate())
+}
+
+func TestStressPathLockProofDoesNotModifyAgentSource(t *testing.T) {
+	sourceDir := os.Getenv("AGENTCOMPAT_AGENT_SOURCE")
+	if sourceDir == "" {
+		t.Skip("AGENTCOMPAT_AGENT_SOURCE is not configured")
+	}
+	path := sourceDir + "/cmd/agent/mcp_fs_path_lock.go"
+	before, err := os.ReadFile(path)
+	require.NoError(t, err)
+	beforeHash := sha256.Sum256(before)
+	proof, err := proveStressPathLockStripes(t.Context(), sourceDir)
+	require.NoError(t, err)
+	require.NoError(t, proof.Validate())
+	after, err := os.ReadFile(path)
+	require.NoError(t, err)
+	require.Equal(t, beforeHash, sha256.Sum256(after))
+}