internal/xds: change xds_resolver to use dependency manager

internal/xds/clients/xdsclient/clientimpl_watchers.go

@@ -19,6 +19,7 @@
 package xdsclient
 
 import (
+	"context"
 	"fmt"
 
 	"google.golang.org/grpc/internal/xds/clients/xdsclient/internal/xdsresource"
@@ -62,15 +63,19 @@ func (c *XDSClient) WatchResource(typeURL, resourceName string, watcher Resource
 	rType, ok := c.config.ResourceTypes[typeURL]
 	if !ok {
 		logger.Warningf("ResourceType implementation for resource type url %v is not found", rType.TypeURL)
-		watcher.ResourceError(fmt.Errorf("ResourceType implementation for resource type url %v is not found", rType.TypeURL), func() {})
+		c.serializer.TrySchedule(func(context.Context) {
+			watcher.ResourceError(fmt.Errorf("ResourceType implementation for resource type url %v is not found", rType.TypeURL), func() {})
+		})
 		return func() {}
 	}
 
 	n := xdsresource.ParseName(resourceName)
 	a := c.getAuthorityForResource(n)
 	if a == nil {
 		logger.Warningf("Watch registered for name %q of type %q, authority %q is not found", rType.TypeName, resourceName, n.Authority)
-		watcher.ResourceError(fmt.Errorf("authority %q not found in bootstrap config for resource %q", n.Authority, resourceName), func() {})
+		c.serializer.TrySchedule(func(context.Context) {
+			watcher.ResourceError(fmt.Errorf("authority %q not found in bootstrap config for resource %q", n.Authority, resourceName), func() {})
+		})
 		return func() {}
 	}
 	// The watchResource method on the authority is invoked with n.String()

internal/xds/resolver/helpers_test.go

@@ -191,26 +191,6 @@ func verifyNoUpdateFromResolver(ctx context.Context, t *testing.T, stateCh chan
 	}
 }
 
-// waitForErrorFromResolver waits for the resolver to push an error and verifies
-// that it matches the expected error and contains the expected node ID.
-func waitForErrorFromResolver(ctx context.Context, errCh chan error, wantErr, wantNodeID string) error {
-	select {
-	case <-ctx.Done():
-		return fmt.Errorf("timeout when waiting for error to be propagated to the ClientConn")
-	case gotErr := <-errCh:
-		if gotErr == nil {
-			return fmt.Errorf("got nil error from resolver, want %q", wantErr)
-		}
-		if !strings.Contains(gotErr.Error(), wantErr) {
-			return fmt.Errorf("got error from resolver %q, want %q", gotErr, wantErr)
-		}
-		if !strings.Contains(gotErr.Error(), wantNodeID) {
-			return fmt.Errorf("got error from resolver %q, want nodeID %q", gotErr, wantNodeID)
-		}
-	}
-	return nil
-}
-
 func verifyResolverError(gotErr error, wantCode codes.Code, wantErr, wantNodeID string) error {
 	if gotErr == nil {
 		return fmt.Errorf("got nil error from resolver, want error with code %v", wantCode)