update docs and add mocks pkg (#610)

Makefile

@@ -1,4 +1,4 @@
-.PHONY: fmt check-fmt lint vet test
+.PHONY: fmt lint test mocks test_coverage
 
 GO_PKGS   := $(shell go list -f {{.Dir}} ./...)
 
@@ -15,3 +15,6 @@ test:
 test_coverage:
 	@go test -race -v $(GO_FLAGS) -count=1 -coverprofile=coverage.out -covermode=atomic $(GO_PKGS)
 	@go tool cover -html coverage.out
+
+mocks:
+	@go generate ./...

README.md

@@ -110,6 +110,15 @@ func main() {
     Global job options can be set when creating a scheduler using `NewScheduler`.
   - [**Scheduler options**](https://pkg.go.dev/github.com/go-co-op/gocron/v2#SchedulerOption):
     Scheduler options can be set when creating a scheduler using `NewScheduler`.
+- **Logging**: Logs can be enabled.
+  - [Logger](https://pkg.go.dev/github.com/go-co-op/gocron/v2#Logger):
+    The Logger interface can be implemented with your desired logging library.
+    The provided NewLogger uses the standard library's log package.
+- **Mocking**: The gocron library is set up to enable testing.
+  - Mocks are provided in [the mock package](mocks) using [gomock](https://github.com/uber-go/mock).
+  - Time can be mocked by passing in a [FakeClock](https://pkg.go.dev/github.com/jonboulle/clockwork#FakeClock)
+    to [WithClock](https://pkg.go.dev/github.com/go-co-op/gocron/v2#WithClock) -
+    see the example on WithClock in the go-docs.
 
 ## Supporters
 

distributed.go

@@ -1,3 +1,4 @@
+//go:generate mockgen -source=distributed.go -destination=mocks/distributed.go -package=gocronmocks
 package gocron
 
 import "context"

job.go

@@ -1,3 +1,4 @@
+//go:generate mockgen -source=job.go -destination=mocks/job.go -package=gocronmocks
 package gocron
 
 import (

logger.go

@@ -1,3 +1,4 @@
+//go:generate mockgen -source=logger.go -destination=mocks/logger.go -package=gocronmocks
 package gocron
 
 import (

mocks/README.md

@@ -0,0 +1,35 @@
+# gocron mocks
+
+## Quick Start
+
+```
+go get github.com/go-co-op/gocronmocks/v2
+```
+
+write a test
+```golang
+package main
+
+import (
+	"testing"
+
+	"github.com/go-co-op/gocron/v2"
+	"github.com/go-co-op/gocronmocks/v2"
+	"go.uber.org/mock/gomock"
+)
+
+func myFunc(s gocron.Scheduler) {
+	s.Start()
+	_ = s.Shutdown()
+}
+
+func TestMyFunc(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	s := gocronmocks.NewMockScheduler(ctrl)
+	s.EXPECT().Start().Times(1)
+	s.EXPECT().Shutdown().Times(1).Return(nil)
+
+	myFunc(s)
+}
+
+```

mocks/go.mod

@@ -0,0 +1,15 @@
+module github.com/go-co-op/gocronmocks/v2
+
+go 1.20
+
+require (
+	github.com/go-co-op/gocron/v2 v2.0.0-rc1
+	github.com/google/uuid v1.4.0
+	go.uber.org/mock v0.3.0
+)
+
+require (
+	github.com/jonboulle/clockwork v0.4.0 // indirect
+	github.com/robfig/cron/v3 v3.0.1 // indirect
+	golang.org/x/exp v0.0.0-20231006140011-7918f672742d // indirect
+)

mocks/go.sum

@@ -0,0 +1,17 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/go-co-op/gocron/v2 v2.0.0-rc1 h1:qkj0WVO6uh6ibZa2CQ0Ifxk3A+c6rawZnIby94/5sAM=
+github.com/go-co-op/gocron/v2 v2.0.0-rc1/go.mod h1:3SLoqKnyORFVN0VvFFb1383hM4WD9XHBPn9aUUp7sQs=
+github.com/google/uuid v1.4.0 h1:MtMxsa51/r9yyhkyLsVeVt0B+BGQZzpQiTQ4eHZ8bc4=
+github.com/google/uuid v1.4.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/jonboulle/clockwork v0.4.0 h1:p4Cf1aMWXnXAUh8lVfewRBx1zaTSYKrKMF2g3ST4RZ4=
+github.com/jonboulle/clockwork v0.4.0/go.mod h1:xgRqUGwRcjKCO1vbZUEtSLrqKoPSsUpK7fnezOII0kc=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/robfig/cron/v3 v3.0.1 h1:WdRxkvbJztn8LMz/QEvLN5sBU+xKpSqwwUO1Pjr4qDs=
+github.com/robfig/cron/v3 v3.0.1/go.mod h1:eQICP3HwyT7UooqI/z+Ov+PtYAWygg1TEWWzGIFLtro=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
+go.uber.org/mock v0.3.0 h1:3mUxI1No2/60yUYax92Pt8eNOEecx2D3lcXZh2NEZJo=
+go.uber.org/mock v0.3.0/go.mod h1:a6FSlNadKUHUa9IP5Vyt1zh4fC7uAwxMutEAscFbkZc=
+golang.org/x/exp v0.0.0-20231006140011-7918f672742d h1:jtJma62tbqLibJ5sFQz8bKtEM8rJBtfilJ2qTU199MI=
+golang.org/x/exp v0.0.0-20231006140011-7918f672742d/go.mod h1:ldy0pHrwJyGW56pPQzzkH36rKxoZW1tw7ZJpeKx+hdo=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=