test(agentcompat): add agent runtime harness

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

integration/agentcompat/internal/agent/adversarial_test.go

@@ -0,0 +1,59 @@
+//go:build linux && agentcompat
+
+package agent
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestAgent_RejectsMalformedStartWithoutWorkspaceArtifact(t *testing.T) {
+	// Given
+	parent := t.TempDir()
+	t.Setenv("TMPDIR", parent)
+
+	// When
+	_, err := Start(t.Context(), AgentStartConfig{SourceDir: filepath.Join(parent, "missing"), Endpoint: "127.0.0.1:1", UUID: "bad"})
+
+	// Then
+	require.Error(t, err)
+	entries, readErr := os.ReadDir(parent)
+	require.NoError(t, readErr)
+	require.Empty(t, entries)
+}
+
+func TestAgent_ContextInterruptionCleansWorkspace(t *testing.T) {
+	// Given
+	processContext, interrupt := context.WithCancel(t.Context())
+	dashboardInstance := startTestDashboard(t, false)
+	agentInstance, err := Start(processContext, AgentStartConfig{
+		SourceDir: testAgentSourceDir(t),
+		Endpoint:  dashboardInstance.Endpoint(),
+		Secret:    dashboardInstance.AgentSecret(),
+		UUID:      "00000000-0000-0000-0000-000000000085",
+	})
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		cleanupContext, cancel := context.WithTimeout(context.Background(), 15*time.Second)
+		defer cancel()
+		require.NoError(t, agentInstance.Stop(cleanupContext))
+	})
+	root := agentInstance.WorkspaceRoot()
+
+	// When
+	interrupt()
+
+	// Then
+	select {
+	case <-agentInstance.CleanupDone():
+	case <-time.After(30 * time.Second):
+		t.Fatal("agent cleanup did not complete")
+	}
+	_, err = os.Stat(root)
+	require.ErrorIs(t, err, os.ErrNotExist)
+}