Add some tests

pkg/loop/internal/test/config.go

@@ -3,11 +3,16 @@ package test
 import (
 	"bytes"
 	"context"
+	"encoding/json"
 	"fmt"
+	"math/big"
+	"time"
 
 	libocr "github.com/smartcontractkit/libocr/offchainreporting2plus/types"
 
 	"github.com/stretchr/testify/assert"
+
+	"github.com/smartcontractkit/chainlink-relay/pkg/types"
 )
 
 type staticConfigProvider struct{}
@@ -85,3 +90,29 @@ func (s staticContractTransmitter) LatestConfigDigestAndEpoch(ctx context.Contex
 func (s staticContractTransmitter) FromAccount() (libocr.Account, error) {
 	return account, nil
 }
+
+type staticChainReader struct{}
+
+func (c staticChainReader) GetLatestValue(ctx context.Context, bc types.BoundContract, method string, params, returnVal any) ([]byte, error) {
+	if !assert.ObjectsAreEqual(bc, boundContract) {
+		return nil, fmt.Errorf("expected report context %v but got %v", boundContract, bc)
+	}
+	if method != medianContractGenericMethod {
+		return nil, fmt.Errorf("expected generic contract method %v but got %v", medianContractGenericMethod, method)
+	}
+	if !assert.ObjectsAreEqual(params, getLatestValueParams) {
+		return nil, fmt.Errorf("expected params %v but got %v", params, getLatestValueParams)
+	}
+
+	retStruct := struct {
+		Epoch           uint32
+		Round           uint8
+		LatestAnswer    *big.Int
+		LatestTimestamp time.Time
+	}{epoch, round, latestAnswer, latestTimestamp}
+	ret, err := json.Marshal(retStruct)
+	if err != nil {
+		return nil, fmt.Errorf("Failed constructing static return data from GetLatestValue")
+	}
+	return ret, nil
+}

pkg/loop/internal/test/median.go

@@ -305,6 +305,10 @@ func (s StaticMedianProvider) OnchainConfigCodec() median.OnchainConfigCodec {
 	return staticOnchainConfigCodec{}
 }
 
+func (s StaticMedianProvider) ChainReader() types.ChainReader {
+	return staticChainReader{}
+}
+
 type staticReportCodec struct{}
 
 func (s staticReportCodec) BuildReport(os []median.ParsedAttributedObservation) (libocr.Report, error) {

pkg/loop/internal/test/plugin_provider.go

@@ -4,6 +4,8 @@ import (
 	"context"
 
 	libocr "github.com/smartcontractkit/libocr/offchainreporting2plus/types"
+
+	"github.com/smartcontractkit/chainlink-relay/pkg/types"
 )
 
 type StaticPluginProvider struct{}
@@ -29,3 +31,7 @@ func (s StaticPluginProvider) ContractConfigTracker() libocr.ContractConfigTrack
 func (s StaticPluginProvider) ContractTransmitter() libocr.ContractTransmitter {
 	return staticContractTransmitter{}
 }
+
+func (s StaticPluginProvider) ChainReader() types.ChainReader {
+	return staticChainReader{}
+}

pkg/loop/internal/test/test.go

@@ -125,4 +125,14 @@ URL = 'https://test.url'
 	signed         = []byte{13: 37}
 	sigs           = []libocr.AttributedOnchainSignature{{Signature: []byte{9: 8, 7: 6}, Signer: commontypes.OracleID(54)}}
 	value          = big.NewInt(999)
+	boundContract  = types.BoundContract{
+		Name:    "my median contract",
+		Address: "0xBbf078A8849D74653e36E6DBBdC7e1a35E657C26",
+		Pending: false,
+	}
+	medianContractGenericMethod = "LatestTransmissionDetails"
+	getLatestValueParams        = struct {
+		Param1 string
+		Param2 string
+	}{"value1", "value2"}
 )