Add sleep-for-days sample (#384)

* sleep-for-days sample

* add test, fixed bugs

Author: THardy98

sleep-for-days/README.md

@@ -0,0 +1,16 @@
+### Sleep for days
+
+This sample demonstrates how to create a Temporal workflow that runs forever, sending an email every 30 days.
+
+### Steps to run this sample:
+1) Run a [Temporal service](https://github.com/temporalio/samples-go/tree/main/#how-to-use).
+2) Run the following command to start the worker
+```
+go run worker/main.go
+```
+3) Run the following command to start the example
+```
+go run starter/main.go
+```
+
+This sample will run indefinitely until you send a `complete` signal to the workflow. See how to send a signal via Temporal CLI [here](https://docs.temporal.io/cli/workflow#signal).

sleep-for-days/sleepfordays_workflow.go

@@ -0,0 +1,37 @@
+package sleepfordays
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"go.temporal.io/sdk/activity"
+	"go.temporal.io/sdk/workflow"
+)
+
+func SleepForDaysWorkflow(ctx workflow.Context) (string, error) {
+	ctx = workflow.WithActivityOptions(ctx, workflow.ActivityOptions{
+		StartToCloseTimeout: 10 * time.Second,
+	})
+
+	isComplete := false
+	sigChan := workflow.GetSignalChannel(ctx, "complete")
+
+	for !isComplete {
+		workflow.ExecuteActivity(ctx, SendEmailActivity, "Sleeping for 30 days")
+		selector := workflow.NewSelector(ctx)
+		selector.AddFuture(workflow.NewTimer(ctx, time.Hour*24*30), func(f workflow.Future) {})
+		selector.AddReceive(sigChan, func(c workflow.ReceiveChannel, more bool) {
+			isComplete = true
+		})
+		selector.Select(ctx)
+	}
+
+	return "done", nil
+}
+
+// A stub Activity for sending an email.
+func SendEmailActivity(ctx context.Context, msg string) error {
+	activity.GetLogger(ctx).Info(fmt.Sprintf(`Sending email: "%v"\n`, msg))
+	return nil
+}

sleep-for-days/sleepfordays_workflow_test.go

@@ -0,0 +1,39 @@
+package sleepfordays
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
+
+	"go.temporal.io/sdk/testsuite"
+)
+
+func TestSleepForDaysWorkflow(t *testing.T) {
+	testSuite := &testsuite.WorkflowTestSuite{}
+	env := testSuite.NewTestWorkflowEnvironment()
+
+	numActivityCalls := 0
+	env.RegisterActivity(SendEmailActivity)
+	env.OnActivity(SendEmailActivity, mock.Anything, mock.Anything).Run(
+		func(args mock.Arguments) { numActivityCalls++ },
+	).Return(nil)
+
+	startTime := env.Now()
+
+	// Time-skip 90 days.
+	env.RegisterDelayedCallback(func() {
+		// Check that the activity has been called 3 times.
+		require.Equal(t, 3, numActivityCalls)
+		// Send the signal to complete the workflow.
+		env.SignalWorkflow("complete", nil)
+		// Expect no more activity calls to have been made - workflow is complete.
+		require.Equal(t, 3, numActivityCalls)
+		// Expect more than 90 days to have passed.
+		require.Equal(t, env.Now().Sub(startTime), time.Hour*24*90)
+	}, time.Hour*24*90)
+
+	// Execute workflow.
+	env.ExecuteWorkflow(SleepForDaysWorkflow)
+}

sleep-for-days/starter/main.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"context"
+	"log"
+
+	sleepfordays "github.com/temporalio/samples-go/sleep-for-days"
+	"go.temporal.io/sdk/client"
+)
+
+func main() {
+	c, err := client.Dial(client.Options{})
+	if err != nil {
+		log.Fatalln("Unable to create client", err)
+	}
+	defer c.Close()
+
+	workflowOptions := client.StartWorkflowOptions{
+		TaskQueue: "sleep-for-days",
+	}
+
+	we, err := c.ExecuteWorkflow(context.Background(), workflowOptions, sleepfordays.SleepForDaysWorkflow)
+	if err != nil {
+		log.Fatalln("Unable to execute workflow", err)
+	}
+
+	log.Println("Started sleep-for-days workflow", "WorkflowID", we.GetID(), "RunID", we.GetRunID())
+
+	// Synchronously wait for the workflow completion (will run indefinitely until it receives a signal)
+	var result string
+	err = we.Get(context.Background(), &result)
+	if err != nil {
+		log.Fatalln("Unable get workflow result", err)
+	}
+	log.Println("Workflow result:", result)
+}

sleep-for-days/worker/main.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"log"
+
+	"go.temporal.io/sdk/client"
+	"go.temporal.io/sdk/worker"
+
+	sleepfordays "github.com/temporalio/samples-go/sleep-for-days"
+)
+
+func main() {
+	// The client and worker are heavyweight objects that should be created once per process.
+	c, err := client.Dial(client.Options{})
+	if err != nil {
+		log.Fatalln("Unable to create client", err)
+	}
+	defer c.Close()
+
+	w := worker.New(c, "sleep-for-days", worker.Options{})
+
+	w.RegisterWorkflow(sleepfordays.SleepForDaysWorkflow)
+	w.RegisterActivity(sleepfordays.SendEmailActivity)
+
+	err = w.Run(worker.InterruptCh())
+	if err != nil {
+		log.Fatalln("Unable to start worker", err)
+	}
+}