scheduler: add unit tests (#150)

Adds unit tests to the scheduler package.

Also adds some helper test utils:
 - app/golden: for golden file testing
 - beaconmock: beacon client mock
 
category: testing
ticket: #145

.pre-commit-config.yaml

@@ -4,7 +4,9 @@ repos:
     rev: v4.1.0
     hooks:
       - id: trailing-whitespace # trims trailing whitespace
+        exclude: "testdata"
       - id: end-of-file-fixer # ensures that a file is either empty, or ends with one newline
+        exclude: "testdata"
       - id: mixed-line-ending # ensures that a file doesn't contain a mix of LF and CRLF
       - id: no-commit-to-branch # Protect specific branches (default: main/master) from direct checkins
 

app/golden/golden.go

@@ -0,0 +1,76 @@
+// Copyright © 2021 Obol Technologies Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package golden provides a test utility for asserting blobs against golden files in a testdata folder.
+// This is heavily inspired from https://github.com/sebdah/goldie.
+package golden
+
+import (
+	"encoding/json"
+	"flag"
+	"os"
+	"path"
+	"strings"
+	"sync"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+var (
+	update = flag.Bool("update", false, "Create or update golden files, instead of comparing them")
+	clean  = flag.Bool("clean", false, "Deletes the testdata folder before updating (noop of update==false)")
+)
+
+var cleanOnce sync.Once
+
+// RequireBytes asserts that a golden testdata file exists containing the exact data.
+func RequireBytes(t *testing.T, data []byte) {
+	t.Helper()
+
+	filename := path.Join("testdata", strings.ReplaceAll(t.Name(), "/", "_"))
+
+	if *update {
+		if *clean {
+			cleanOnce.Do(func() {
+				_ = os.RemoveAll("testdata")
+			})
+		}
+
+		require.NoError(t, os.MkdirAll("testdata", 0o755))
+
+		_ = os.Remove(filename)
+		require.NoError(t, os.WriteFile(filename, data, 0o644)) //nolint:gosec
+
+		return
+	}
+
+	expected, err := os.ReadFile(filename)
+	if os.IsNotExist(err) {
+		t.Fatalf("golden file does not exist, %s, generate by running with -update", filename)
+		return
+	}
+
+	require.Equalf(t, expected, data, "Golden file mismatch, %s", filename)
+}
+
+// RequireJSON asserts that a golden testdata file exists containing the JSON serialised form of the data object.
+func RequireJSON(t *testing.T, data interface{}) {
+	t.Helper()
+
+	b, err := json.MarshalIndent(data, "", " ")
+	require.NoError(t, err)
+
+	RequireBytes(t, b)
+}

beaconmock/beaconmock.go

@@ -0,0 +1,99 @@
+// Copyright © 2021 Obol Technologies Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package beaconmock provides a mock beacon client primarily for testing.
+package beaconmock
+
+import (
+	"context"
+	"time"
+
+	eth2client "github.com/attestantio/go-eth2-client"
+	eth2v1 "github.com/attestantio/go-eth2-client/api/v1"
+	eth2p0 "github.com/attestantio/go-eth2-client/spec/phase0"
+)
+
+// Interface assertions.
+var (
+	_ eth2client.Service                = (*Mock)(nil)
+	_ eth2client.NodeSyncingProvider    = (*Mock)(nil)
+	_ eth2client.GenesisTimeProvider    = (*Mock)(nil)
+	_ eth2client.ValidatorsProvider     = (*Mock)(nil)
+	_ eth2client.SlotsPerEpochProvider  = (*Mock)(nil)
+	_ eth2client.SlotDurationProvider   = (*Mock)(nil)
+	_ eth2client.AttesterDutiesProvider = (*Mock)(nil)
+	_ eth2client.ProposerDutiesProvider = (*Mock)(nil)
+)
+
+// NewMock returns a new beacon client mock configured with the default and provided options.
+func NewMock(opts ...Option) Mock {
+	mock := defaultMock()
+	for _, opt := range opts {
+		opt(&mock)
+	}
+
+	return mock
+}
+
+// Mock provides a mock beacon client and implements eth2client.Service and many of the erh2client Providers.
+type Mock struct {
+	ProposerDutiesFunc     func(context.Context, eth2p0.Epoch, []eth2p0.ValidatorIndex) ([]*eth2v1.ProposerDuty, error)
+	AttesterDutiesFunc     func(context.Context, eth2p0.Epoch, []eth2p0.ValidatorIndex) ([]*eth2v1.AttesterDuty, error)
+	SlotDurationFunc       func(context.Context) (time.Duration, error)
+	SlotsPerEpochFunc      func(context.Context) (uint64, error)
+	ValidatorsFunc         func(context.Context, string, []eth2p0.ValidatorIndex) (map[eth2p0.ValidatorIndex]*eth2v1.Validator, error)
+	ValidatorsByPubKeyFunc func(context.Context, string, []eth2p0.BLSPubKey) (map[eth2p0.ValidatorIndex]*eth2v1.Validator, error)
+	GenesisTimeFunc        func(context.Context) (time.Time, error)
+	NodeSyncingFunc        func(context.Context) (*eth2v1.SyncState, error)
+}
+
+func (m Mock) ProposerDuties(ctx context.Context, epoch eth2p0.Epoch, validatorIndices []eth2p0.ValidatorIndex) ([]*eth2v1.ProposerDuty, error) {
+	return m.ProposerDutiesFunc(ctx, epoch, validatorIndices)
+}
+
+func (m Mock) AttesterDuties(ctx context.Context, epoch eth2p0.Epoch, validatorIndices []eth2p0.ValidatorIndex) ([]*eth2v1.AttesterDuty, error) {
+	return m.AttesterDutiesFunc(ctx, epoch, validatorIndices)
+}
+
+func (m Mock) SlotDuration(ctx context.Context) (time.Duration, error) {
+	return m.SlotDurationFunc(ctx)
+}
+
+func (m Mock) SlotsPerEpoch(ctx context.Context) (uint64, error) {
+	return m.SlotsPerEpochFunc(ctx)
+}
+
+func (m Mock) Validators(ctx context.Context, stateID string, validatorIndices []eth2p0.ValidatorIndex) (map[eth2p0.ValidatorIndex]*eth2v1.Validator, error) {
+	return m.ValidatorsFunc(ctx, stateID, validatorIndices)
+}
+
+func (m Mock) ValidatorsByPubKey(ctx context.Context, stateID string, validatorPubKeys []eth2p0.BLSPubKey) (map[eth2p0.ValidatorIndex]*eth2v1.Validator, error) {
+	return m.ValidatorsByPubKeyFunc(ctx, stateID, validatorPubKeys)
+}
+
+func (m Mock) GenesisTime(ctx context.Context) (time.Time, error) {
+	return m.GenesisTimeFunc(ctx)
+}
+
+func (m Mock) NodeSyncing(ctx context.Context) (*eth2v1.SyncState, error) {
+	return m.NodeSyncingFunc(ctx)
+}
+
+func (Mock) Name() string {
+	return "beacon-mock"
+}
+
+func (Mock) Address() string {
+	return "mock-address"
+}