Add /eth/v1/beacon/deposit_snapshot endpoint (#13514)

* Add endpoint

* Uncomment in InitializeRoutes

* Add test

* Add 404

* Add more checks

* Test improvements

* Ssz

* Add ssz tags

* Add DepositSnapshot to bazel

* Fix tests

* Fix max size

* Resolve conflicts

* Revert untouched code

* Fix test + review

* Lint

* Oops

* Preston + Radek' review

* Only return 3 finalized roots

* Change to deposit contract depth

* Radek' review

* Gaz

---------

Co-authored-by: james-prysm <90280386+james-prysm@users.noreply.github.com>

api/server/structs/BUILD.bazel

@@ -1,4 +1,4 @@
-load("@prysm//tools/go:def.bzl", "go_library")
+load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
@@ -38,3 +38,13 @@ go_library(
         "@com_github_pkg_errors//:go_default_library",
     ],
 )
+
+go_test(
+    name = "go_default_test",
+    srcs = ["conversions_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//proto/prysm/v1alpha1:go_default_library",
+        "//testing/require:go_default_library",
+    ],
+)

api/server/structs/conversions.go

@@ -1074,3 +1074,17 @@ func sszBytesToUint256String(b []byte) (string, error) {
 	}
 	return bi.String(), nil
 }
+
+func DepositSnapshotFromConsensus(ds *eth.DepositSnapshot) *DepositSnapshot {
+	finalized := make([]string, 0, len(ds.Finalized))
+	for _, f := range ds.Finalized {
+		finalized = append(finalized, hexutil.Encode(f))
+	}
+	return &DepositSnapshot{
+		Finalized:            finalized,
+		DepositRoot:          hexutil.Encode(ds.DepositRoot),
+		DepositCount:         fmt.Sprintf("%d", ds.DepositCount),
+		ExecutionBlockHash:   hexutil.Encode(ds.ExecutionHash),
+		ExecutionBlockHeight: fmt.Sprintf("%d", ds.ExecutionDepth),
+	}
+}

api/server/structs/conversions_test.go

@@ -0,0 +1,26 @@
+package structs
+
+import (
+	"testing"
+
+	eth "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+)
+
+func TestDepositSnapshotFromConsensus(t *testing.T) {
+	ds := &eth.DepositSnapshot{
+		Finalized:      [][]byte{{0xde, 0xad, 0xbe, 0xef}, {0xca, 0xfe, 0xba, 0xbe}},
+		DepositRoot:    []byte{0xab, 0xcd},
+		DepositCount:   12345,
+		ExecutionHash:  []byte{0x12, 0x34},
+		ExecutionDepth: 67890,
+	}
+
+	res := DepositSnapshotFromConsensus(ds)
+	require.NotNil(t, res)
+	require.DeepEqual(t, []string{"0xdeadbeef", "0xcafebabe"}, res.Finalized)
+	require.Equal(t, "0xabcd", res.DepositRoot)
+	require.Equal(t, "12345", res.DepositCount)
+	require.Equal(t, "0x1234", res.ExecutionBlockHash)
+	require.Equal(t, "67890", res.ExecutionBlockHeight)
+}

api/server/structs/endpoints_beacon.go

@@ -184,3 +184,15 @@ type WeakSubjectivityData struct {
 	WsCheckpoint *Checkpoint `json:"ws_checkpoint"`
 	StateRoot    string      `json:"state_root"`
 }
+
+type GetDepositSnapshotResponse struct {
+	Data *DepositSnapshot `json:"data"`
+}
+
+type DepositSnapshot struct {
+	Finalized            []string `json:"finalized"`
+	DepositRoot          string   `json:"deposit_root"`
+	DepositCount         string   `json:"deposit_count"`
+	ExecutionBlockHash   string   `json:"execution_block_hash"`
+	ExecutionBlockHeight string   `json:"execution_block_height"`
+}