fix(oracle): The timestamps resulting from ctx.WithBlock* don't actually

correspond to the block header information from specified blocks in the
chain's history, so the oracle exchange rates need a way to correctly
retrieve this information. This change fixes that discrepency, giving
the expected block timesamp for the EVM's oracle precompiled contract.
The change also simplifies and corrects the code in x/oracle.

refactor(oralce): rename querier -> grpc_query for consistency with the rest of the codebase

CHANGELOG.md

@@ -107,6 +107,12 @@ tests for race conditions within funtoken precompile
 - [#2111](https://github.com/NibiruChain/nibiru/pull/2111) - fix: e2e-evm-cron.yml
 - [#2114](https://github.com/NibiruChain/nibiru/pull/2114) - fix(evm): make gas cost zero in conditional bank keeper flow
 - [#2116](https://github.com/NibiruChain/nibiru/pull/2116) - fix(precompile-funtoken.go): Fixes a bug where the err != nil check is missing in the bankBalance precompile method
+- [#2117](https://github.com/NibiruChain/nibiru/pull/2117) - fix(oracle): The
+timestamps resulting from ctx.WithBlock* don't actually correspond to the block
+header information from specified blocks in the chain's history, so the oracle
+exchange rates need a way to correctly retrieve this information. This change
+fixes that discrepency, giving the expected block timesamp for the EVM's oracle
+precompiled contract. The change also simplifies and corrects the code in x/oracle.
 
 #### Nibiru EVM | Before Audit 1 - 2024-10-18
 

app/wasmext/stargate_query.go

@@ -120,7 +120,6 @@ func WasmAcceptedStargateQueries() wasmkeeper.AcceptedStargateQueries {
 
 		// nibiru oracle
 		"/nibiru.oracle.v1.Query/ExchangeRate":      new(oracle.QueryExchangeRateResponse),
-		"/nibiru.oracle.v1.Query/DatedExchangeRate": new(oracle.QueryDatedExchangeRateResponse),
 		"/nibiru.oracle.v1.Query/ExchangeRateTwap":  new(oracle.QueryExchangeRateResponse),
 		"/nibiru.oracle.v1.Query/ExchangeRates":     new(oracle.QueryExchangeRatesResponse),
 		"/nibiru.oracle.v1.Query/Actives":           new(oracle.QueryActivesResponse),

eth/rpc/backend/blocks_test.go

@@ -16,7 +16,9 @@ func (s *BackendSuite) TestBlockNumber() {
 	latestHeight, _ := s.network.LatestHeight()
 	resp, err := s.backend.BlockNumber()
 	s.Require().NoError(err, resp)
-	s.Require().Equal(uint64(latestHeight), uint64(blockHeight))
+	// Rather than checking exact equality, which might not be true due to
+	// latency. Add a cushion of 2 blocks.
+	s.Require().LessOrEqual(uint64(latestHeight)-uint64(blockHeight), 2)
 }
 
 func (s *BackendSuite) TestGetBlockByNumberr() {

proto/nibiru/oracle/v1/oracle.proto

@@ -130,14 +130,19 @@ message ExchangeRateTuple {
   ];
 }
 
-message DatedPrice {
+message ExchangeRateAtBlock {
   string exchange_rate = 1 [
     (gogoproto.moretags) = "yaml:\"exchange_rate\"",
     (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec",
     (gogoproto.nullable) = false
   ];
 
   uint64 created_block = 2 [ (gogoproto.moretags) = "yaml:\"created_block\"" ];
+
+  // Block timestamp for the block where the oracle came to consensus for this
+  // price. This timestamp is a conventional Unix millisecond time, i.e. the
+  // number of milliseconds elapsed since January 1, 1970 UTC. 
+  int64 block_timestamp_ms = 3 [ (gogoproto.moretags) = "yaml:\"block_timestamp_ms\"" ];
 }
 
 // Rewards defines a credit object towards validators

proto/nibiru/oracle/v1/query.proto

@@ -10,7 +10,8 @@ option go_package = "github.com/NibiruChain/nibiru/v2/x/oracle/types";
 
 // Query defines the gRPC querier service.
 service Query {
-  // ExchangeRate returns exchange rate of a pair
+  // ExchangeRate returns exchange rate of a pair along with the block height and
+  // block time that the exchange rate was set by the oracle module.
   rpc ExchangeRate(QueryExchangeRateRequest)
       returns (QueryExchangeRateResponse) {
     option (google.api.http).get = "/nibiru/oracle/v1beta1/exchange_rate";
@@ -22,12 +23,6 @@ service Query {
     option (google.api.http).get = "/nibiru/oracle/v1beta1/exchange_rate_twap";
   }
 
-  // DatedExchangeRate returns latest price of a pair
-  rpc DatedExchangeRate(QueryExchangeRateRequest)
-      returns (QueryDatedExchangeRateResponse) {
-    option (google.api.http).get = "/nibiru/oracle/v1beta1/dated_exchange_rate";
-  }
-
   // ExchangeRates returns exchange rates of all pairs
   rpc ExchangeRates(QueryExchangeRatesRequest)
       returns (QueryExchangeRatesResponse) {
@@ -114,20 +109,6 @@ message QueryExchangeRateResponse {
     (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec",
     (gogoproto.nullable) = false
   ];
-}
-
-// QueryExchangeRatesRequest is the request type for the Query/ExchangeRates RPC
-// method.
-message QueryExchangeRatesRequest {
-}
-
-// QueryDatedExchangeRateResponse is the request type for the 
-// Query/DatedExchangeRate RPC method.
-message QueryDatedExchangeRateResponse {
-  string price = 1 [
-    (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec",
-    (gogoproto.nullable) = false
-  ];
 
   // Block timestamp for the block where the oracle came to consensus for this
   // price. This timestamp is a conventional Unix millisecond time, i.e. the
@@ -138,6 +119,11 @@ message QueryDatedExchangeRateResponse {
   uint64 block_height = 3;
 }
 
+// QueryExchangeRatesRequest is the request type for the Query/ExchangeRates RPC
+// method.
+message QueryExchangeRatesRequest {
+}
+
 // QueryExchangeRatesResponse is response type for the
 // Query/ExchangeRates RPC method.
 message QueryExchangeRatesResponse {

x/evm/precompile/oracle.go

@@ -89,12 +89,16 @@ func (p precompileOracle) queryExchangeRate(
 		return nil, err
 	}
 
-	price, blockTime, blockHeight, err := p.oracleKeeper.GetDatedExchangeRate(ctx, assetPair)
+	priceAtBlock, err := p.oracleKeeper.ExchangeRates.Get(ctx, assetPair)
 	if err != nil {
 		return nil, err
 	}
 
-	return method.Outputs.Pack(price.BigInt(), uint64(blockTime), blockHeight)
+	return method.Outputs.Pack(
+		priceAtBlock.ExchangeRate.BigInt(),
+		uint64(priceAtBlock.BlockTimestampMs),
+		priceAtBlock.CreatedBlock,
+	)
 }
 
 func (p precompileOracle) parseQueryExchangeRateArgs(args []any) (

x/evm/precompile/oracle_test.go

@@ -1,6 +1,7 @@
 package precompile_test
 
 import (
+	"fmt"
 	"math/big"
 	"testing"
 	"time"
@@ -9,6 +10,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/stretchr/testify/suite"
 
+	"github.com/NibiruChain/nibiru/v2/x/evm"
 	"github.com/NibiruChain/nibiru/v2/x/evm/embeds"
 	"github.com/NibiruChain/nibiru/v2/x/evm/evmtest"
 	"github.com/NibiruChain/nibiru/v2/x/evm/precompile"
@@ -56,14 +58,12 @@ func (s *OracleSuite) TestOracle_FailToPackABI() {
 
 func (s *OracleSuite) TestOracle_HappyPath() {
 	deps := evmtest.NewTestDeps()
-
-	s.T().Log("Query exchange rate")
-	{
-		deps.Ctx = deps.Ctx.WithBlockTime(time.Unix(69, 420)).WithBlockHeight(69)
-		deps.App.OracleKeeper.SetPrice(deps.Ctx, "unibi:uusd", sdk.MustNewDecFromStr("0.067"))
-
-		resp, err := deps.EvmKeeper.CallContract(
-			deps.Ctx,
+	runQuery := func(ctx sdk.Context) (
+		resp *evm.MsgEthereumTxResponse,
+		err error,
+	) {
+		return deps.EvmKeeper.CallContract(
+			ctx,
 			embeds.SmartContract_Oracle.ABI,
 			deps.Sender.EthAddr,
 			&precompile.PrecompileAddr_Oracle,
@@ -72,16 +72,47 @@ func (s *OracleSuite) TestOracle_HappyPath() {
 			"queryExchangeRate",
 			"unibi:uusd",
 		)
+	}
+
+	s.T().Log("Query exchange rate")
+	{
+		// 69 seconds + 420 nanoseconds === 69000 milliseconds for the
+		// return value from the UnixMilli() function
+		deps.Ctx = deps.Ctx.WithBlockTime(time.Unix(69, 420)).WithBlockHeight(69)
+		deps.App.OracleKeeper.SetPrice(deps.Ctx, "unibi:uusd", sdk.MustNewDecFromStr("0.067"))
+
+		resp, err := runQuery(deps.Ctx)
 		s.NoError(err)
 
 		// Check the response
-		out, err := embeds.SmartContract_Oracle.ABI.Unpack(string(precompile.OracleMethod_queryExchangeRate), resp.Ret)
+		out, err := embeds.SmartContract_Oracle.ABI.Unpack(
+			string(precompile.OracleMethod_queryExchangeRate), resp.Ret,
+		)
+		s.NoError(err)
+		s.Equal(out[0].(*big.Int), big.NewInt(67_000_000_000_000_000))
+		s.Equal(fmt.Sprintf("%d", out[1].(uint64)), "69000")
+		s.Equal(fmt.Sprintf("%d", out[2].(uint64)), "69")
+	}
+
+	s.T().Log("Query from a later time")
+	{
+		secondsLater := deps.Ctx.BlockTime().Add(100 * time.Second)
+		resp, err := runQuery(deps.Ctx.
+			WithBlockTime(secondsLater).
+			WithBlockHeight(deps.Ctx.BlockHeight() + 50),
+		)
 		s.NoError(err)
 
 		// Check the response
-		s.Equal(out[0].(*big.Int), big.NewInt(67000000000000000))
-		s.Equal(out[1].(uint64), uint64(69000))
-		s.Equal(out[2].(uint64), uint64(69))
+		out, err := embeds.SmartContract_Oracle.ABI.Unpack(
+			string(precompile.OracleMethod_queryExchangeRate), resp.Ret,
+		)
+		s.NoError(err)
+		// These terms should still be equal because the latest exchange rate
+		// has not changed.
+		s.Equal(out[0].(*big.Int), big.NewInt(67_000_000_000_000_000))
+		s.Equal(fmt.Sprintf("%d", out[1].(uint64)), "69000")
+		s.Equal(fmt.Sprintf("%d", out[2].(uint64)), "69")
 	}
 }
 

x/oracle/genesis_test.go

@@ -17,7 +17,12 @@ func TestExportInitGenesis(t *testing.T) {
 
 	input.OracleKeeper.Params.Set(input.Ctx, types.DefaultParams())
 	input.OracleKeeper.FeederDelegations.Insert(input.Ctx, keeper.ValAddrs[0], keeper.Addrs[1])
-	input.OracleKeeper.ExchangeRates.Insert(input.Ctx, "pair1:pair2", types.DatedPrice{ExchangeRate: math.LegacyNewDec(123), CreatedBlock: 0})
+	input.OracleKeeper.ExchangeRates.Insert(input.Ctx, "pair1:pair2",
+		types.ExchangeRateAtBlock{
+			ExchangeRate:     math.LegacyNewDec(123),
+			CreatedBlock:     0,
+			BlockTimestampMs: 0,
+		})
 	input.OracleKeeper.Prevotes.Insert(input.Ctx, keeper.ValAddrs[0], types.NewAggregateExchangeRatePrevote(types.AggregateVoteHash{123}, keeper.ValAddrs[0], uint64(2)))
 	input.OracleKeeper.Votes.Insert(input.Ctx, keeper.ValAddrs[0], types.NewAggregateExchangeRateVote(types.ExchangeRateTuples{{Pair: "foo", ExchangeRate: math.LegacyNewDec(123)}}, keeper.ValAddrs[0]))
 	input.OracleKeeper.WhitelistedPairs.Insert(input.Ctx, "pair1:pair1")

x/oracle/keeper/querier.go → x/oracle/keeper/grpc_query.go

@@ -50,12 +50,15 @@ func (q querier) ExchangeRate(c context.Context, req *types.QueryExchangeRateReq
 	}
 
 	ctx := sdk.UnwrapSDKContext(c)
-	exchangeRate, err := q.Keeper.GetExchangeRate(ctx, req.Pair)
+	out, err := q.Keeper.ExchangeRates.Get(ctx, req.Pair)
 	if err != nil {
 		return nil, err
 	}
-
-	return &types.QueryExchangeRateResponse{ExchangeRate: exchangeRate}, nil
+	return &types.QueryExchangeRateResponse{
+		ExchangeRate:     out.ExchangeRate,
+		BlockTimestampMs: out.BlockTimestampMs,
+		BlockHeight:      out.CreatedBlock,
+	}, nil
 }
 
 /*
@@ -79,24 +82,6 @@ func (q querier) ExchangeRateTwap(c context.Context, req *types.QueryExchangeRat
 	return &types.QueryExchangeRateResponse{ExchangeRate: twap}, nil
 }
 
-// get the latest price snapshot from the oracle for a pair
-func (q querier) DatedExchangeRate(c context.Context, req *types.QueryExchangeRateRequest) (response *types.QueryDatedExchangeRateResponse, err error) {
-	if _, err = q.ExchangeRate(c, req); err != nil {
-		return
-	}
-
-	ctx := sdk.UnwrapSDKContext(c)
-	price, blockTime, blockHeight, err := q.Keeper.GetDatedExchangeRate(ctx, req.Pair)
-	if err != nil {
-		return &types.QueryDatedExchangeRateResponse{}, err
-	}
-	return &types.QueryDatedExchangeRateResponse{
-		Price:            price,
-		BlockTimestampMs: blockTime,
-		BlockHeight:      blockHeight,
-	}, nil
-}
-
 // ExchangeRates queries exchange rates of all pairs
 func (q querier) ExchangeRates(c context.Context, _ *types.QueryExchangeRatesRequest) (*types.QueryExchangeRatesResponse, error) {
 	ctx := sdk.UnwrapSDKContext(c)