BCF-3242 Codec Float/Int Type Loss (#13414)

* add new hook and make decode function

* updated tester to encode/decode config

* remove common replace

* mod tidy

core/services/relay/evm/codec.go

@@ -29,7 +29,13 @@ import (
 // SliceToArrayVerifySizeHook verifies that slices have the correct size when converting to an array
 // sizeVerifyBigIntHook allows our custom types that verify the number fits in the on-chain type to be converted as-if
 // it was a *big.Int
-var evmDecoderHooks = []mapstructure.DecodeHookFunc{decodeAccountAndAllowArraySliceHook, codec.BigIntHook, codec.SliceToArrayVerifySizeHook, sizeVerifyBigIntHook}
+var evmDecoderHooks = []mapstructure.DecodeHookFunc{
+	decodeAccountAndAllowArraySliceHook,
+	codec.BigIntHook,
+	codec.SliceToArrayVerifySizeHook,
+	sizeVerifyBigIntHook,
+	codec.NumberHook,
+}
 
 // NewCodec creates a new [commontypes.RemoteCodec] for EVM.
 // Note that names in the ABI are converted to Go names using [abi.ToCamelCase],

core/services/relay/evm/evmtesting/chain_reader_interface_tester.go

@@ -2,6 +2,7 @@ package evmtesting
 
 import (
 	"context"
+	"encoding/json"
 	"math/big"
 	"time"
 
@@ -201,7 +202,14 @@ func (it *EVMChainReaderInterfaceTester[T]) GetChainReader(t T) clcommontypes.Co
 	lp := logpoller.NewLogPoller(logpoller.NewORM(it.Helper.ChainID(), db, lggr), it.client, lggr, lpOpts)
 	require.NoError(t, lp.Start(ctx))
 
-	cr, err := evm.NewChainReaderService(ctx, lggr, lp, it.client, it.chainConfig)
+	// encode and decode the config to ensure the test covers type issues
+	confBytes, err := json.Marshal(it.chainConfig)
+	require.NoError(t, err)
+
+	conf, err := types.ChainReaderConfigFromBytes(confBytes)
+	require.NoError(t, err)
+
+	cr, err := evm.NewChainReaderService(ctx, lggr, lp, it.client, conf)
 	require.NoError(t, err)
 	require.NoError(t, cr.Start(ctx))
 	it.cr = cr

core/services/relay/evm/types/types.go

@@ -274,3 +274,19 @@ type LogPollerWrapper interface {
 	// TODO (FUN-668): Remove from the LOOP interface and only use internally within the EVM relayer
 	SubscribeToUpdates(ctx context.Context, name string, subscriber RouteUpdateSubscriber)
 }
+
+// ChainReaderConfigFromBytes function applies json decoding on provided bytes to return a
+// valid ChainReaderConfig. If other unmarshaling or parsing techniques are required, place it
+// here.
+func ChainReaderConfigFromBytes(bts []byte) (ChainReaderConfig, error) {
+	decoder := json.NewDecoder(bytes.NewBuffer(bts))
+
+	decoder.UseNumber()
+
+	var cfg ChainReaderConfig
+	if err := decoder.Decode(&cfg); err != nil {
+		return cfg, fmt.Errorf("failed to unmarshal chain reader config err: %s", err)
+	}
+
+	return cfg, nil
+}

go.mod

@@ -348,5 +348,4 @@ replace (
 
 	// until merged upstream: https://github.com/mwitkow/grpc-proxy/pull/69
 	github.com/mwitkow/grpc-proxy => github.com/smartcontractkit/grpc-proxy v0.0.0-20230731113816-f1be6620749f
-
 )