add more tests

Signed-off-by: odubajDT <[email protected]>

Author: odubajDT

exporter/loadbalancingexporter/resolver_k8s.go

@@ -173,16 +173,14 @@ func (r *k8sResolver) start(_ context.Context) error {
 			},
 		}
 
-		if r.epsListWatcher != nil {
-			r.logger.Debug("creating and starting endpoints informer")
-			epsInformer := cache.NewSharedInformer(r.epsListWatcher, &discoveryv1.EndpointSlice{}, 0)
-			if _, err := epsInformer.AddEventHandler(r.handler); err != nil {
-				r.logger.Error("unable to start watching for changes to the specified service names", zap.Error(err))
-			}
-			go epsInformer.Run(r.stopCh)
-			if !cache.WaitForCacheSync(r.stopCh, epsInformer.HasSynced) {
-				initErr = errors.New("endpoints informer not sync")
-			}
+		r.logger.Debug("creating and starting endpoints informer")
+		epsInformer := cache.NewSharedInformer(r.epsListWatcher, &discoveryv1.EndpointSlice{}, 0)
+		if _, err := epsInformer.AddEventHandler(r.handler); err != nil {
+			r.logger.Error("unable to start watching for changes to the specified service names", zap.Error(err))
+		}
+		go epsInformer.Run(r.stopCh)
+		if !cache.WaitForCacheSync(r.stopCh, epsInformer.HasSynced) {
+			initErr = errors.New("endpoints informer not sync")
 		}
 	})
 	if initErr != nil {

exporter/loadbalancingexporter/resolver_k8s_validation_test.go

@@ -12,6 +12,7 @@ import (
 	"go.opentelemetry.io/collector/config/configoptional"
 	"go.opentelemetry.io/collector/exporter/exportertest"
 	"go.uber.org/zap"
+	"k8s.io/client-go/kubernetes/fake"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/exporter/loadbalancingexporter/internal/metadata"
 )
@@ -98,6 +99,71 @@ func TestK8sResolverStartCreatesClient(t *testing.T) {
 	_ = resolver.shutdown(t.Context())
 }
 
+// TestK8sResolverStartErrorPropagation verifies that errors from newInClusterClient() are properly returned from start()
+func TestK8sResolverStartErrorPropagation(t *testing.T) {
+	_, tb := getTelemetryAssets(t)
+
+	// Create resolver with nil client - it will attempt to create a real k8s client on start()
+	resolver, err := newK8sResolver(
+		nil,
+		zap.NewNop(),
+		"test-service",
+		[]int32{4317},
+		defaultListWatchTimeout,
+		false,
+		tb,
+	)
+	require.NoError(t, err)
+	require.Nil(t, resolver.client, "client should be nil before start")
+
+	// When running outside a k8s cluster, start() should fail with an error from newInClusterClient()
+	// This test verifies that the error is properly propagated
+	err = resolver.start(context.Background())
+
+	// Outside a k8s cluster, we expect an error from newInClusterClient()
+	// The error should be returned from start(), not silently ignored
+	// The actual error may vary (e.g., "unable to load in-cluster configuration"), but it should not be nil
+	if err != nil {
+		// This is the expected behavior outside a k8s cluster
+		t.Logf("Expected error from start() outside k8s cluster: %v", err)
+	} else {
+		// If we're running inside a k8s cluster, start() might succeed
+		t.Log("start() succeeded - likely running inside a k8s cluster")
+		require.NotNil(t, resolver.client, "client must be created when start() succeeds")
+		// Clean up
+		_ = resolver.shutdown(context.Background())
+	}
+}
+
+// TestK8sResolverStartWithClientDoesNotCreateNew verifies that when a client is provided, start() does not create a new one
+func TestK8sResolverStartWithClientDoesNotCreateNew(t *testing.T) {
+	_, tb := getTelemetryAssets(t)
+
+	// Create a fake client
+	fakeClient := fake.NewSimpleClientset()
+
+	resolver, err := newK8sResolver(
+		fakeClient,
+		zap.NewNop(),
+		"test-service",
+		[]int32{4317},
+		defaultListWatchTimeout,
+		false,
+		tb,
+	)
+	require.NoError(t, err)
+	require.NotNil(t, resolver.client, "client should be set")
+	require.Equal(t, fakeClient, resolver.client, "client should be the one provided")
+
+	// Start with an existing client should not attempt to create a new one
+	err = resolver.start(context.Background())
+	require.NoError(t, err)
+	require.Equal(t, fakeClient, resolver.client, "client should still be the one provided, not replaced")
+
+	// Clean up
+	_ = resolver.shutdown(context.Background())
+}
+
 // TestLoadBalancerWithK8sResolverCreation tests that loadbalancer can be created with k8s resolver
 func TestLoadBalancerWithK8sResolverCreation(t *testing.T) {
 	ts, tb := getTelemetryAssets(t)