Tests for builder service (#11214)

* Tests for builder service

* fix glob

* minor changes to mock

* add comments to mock

* Revert "Auxiliary commit to revert individual files from bc62a140347e3cbd8bd82e99cf5e9deb98b74df0"

This reverts commit c4c1016cb597b9340d1c81ab3816e037a6b97f9e.

* correct comment

* Do not init builder for empty endpoint

* revert  merging issues

* better nil checks

* test fix

Co-authored-by: terencechain <terence@prysmaticlabs.com>
Co-authored-by: Raul Jordan <raul@prysmaticlabs.com>
Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>

api/client/builder/testing/mock.go

@@ -0,0 +1,49 @@
+package testing
+
+import (
+	"context"
+
+	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
+	v1 "github.com/prysmaticlabs/prysm/v3/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
+)
+
+// MockClient is a mock implementation of BuilderClient.
+type MockClient struct {
+	RegisteredVals map[[48]byte]bool
+}
+
+// NewClient creates a new, correctly initialized mock.
+func NewClient() MockClient {
+	return MockClient{RegisteredVals: map[[48]byte]bool{}}
+}
+
+// NodeURL --
+func (MockClient) NodeURL() string {
+	return ""
+}
+
+// GetHeader --
+func (MockClient) GetHeader(_ context.Context, _ types.Slot, _ [32]byte, _ [48]byte) (*ethpb.SignedBuilderBid, error) {
+	return nil, nil
+}
+
+// RegisterValidator --
+func (m MockClient) RegisterValidator(_ context.Context, svr []*ethpb.SignedValidatorRegistrationV1) error {
+	for _, r := range svr {
+		b := bytesutil.ToBytes48(r.Message.Pubkey)
+		m.RegisteredVals[b] = true
+	}
+	return nil
+}
+
+// SubmitBlindedBlock --
+func (MockClient) SubmitBlindedBlock(_ context.Context, _ *ethpb.SignedBlindedBeaconBlockBellatrix) (*v1.ExecutionPayload, error) {
+	return nil, nil
+}
+
+// Status --
+func (MockClient) Status(_ context.Context) error {
+	return nil
+}