Stop channel for master/worker also making sure no os.Exit is used

internal/bulk/bulk.go

@@ -2,6 +2,7 @@ package bulk
 
 import (
 	"bufio"
+	"errors"
 	"fmt"
 	"os"
 	"strings"
@@ -103,7 +104,7 @@ func (b *Bulk) Start() {
 			case <-kill.KillCtx.Done():
 				console.Warning("Unexpected shutdown while sending emails.")
 
-				os.Exit(1)
+				return errors.New("Shutdown")
 			default:
 				time.Sleep(time.Duration(b.config.GetSendDelay()) * time.Millisecond)
 				b.emailClient.Send(&mail)

internal/validate/master.go

@@ -3,18 +3,21 @@ package validate
 import (
 	"sync"
 
+	"github.com/Siposattila/gobulk/internal/console"
 	"github.com/schollz/progressbar/v3"
 )
 
 type MasterInterface interface {
 	NewWork(fn func())
 	Start()
+	Stop()
 	Wait()
 }
 
 type master struct {
 	maxWorkers int
 	pending    chan *work
+	stop       chan bool
 	bar        *progressbar.ProgressBar
 	wg         sync.WaitGroup
 }
@@ -27,6 +30,7 @@ func NewMaster(totalWork int64, maxWorkers int) MasterInterface {
 	return &master{
 		maxWorkers: maxWorkers,
 		pending:    make(chan *work),
+		stop:       make(chan bool),
 		bar:        progressbar.Default(totalWork),
 	}
 }
@@ -40,10 +44,15 @@ func (m *master) NewWork(fn func()) {
 
 func (m *master) worker() {
 	for {
-		w := <-m.pending
-		m.bar.Add(1)
-		w.fn()
-		m.wg.Done()
+		select {
+		case <-m.stop:
+			return
+		default:
+			w := <-m.pending
+			m.bar.Add(1)
+			w.fn()
+			m.wg.Done()
+		}
 	}
 }
 
@@ -53,6 +62,12 @@ func (m *master) Start() {
 	}
 }
 
+func (m *master) Stop() {
+	for i := 0; i < m.maxWorkers; i++ {
+		m.stop <- true
+	}
+}
+
 func (m *master) Wait() {
 	m.wg.Wait()
 }

internal/validate/validate.go

@@ -1,7 +1,7 @@
 package validate
 
 import (
-	"os"
+	"errors"
 
 	"github.com/Siposattila/gobulk/internal/console"
 	"github.com/Siposattila/gobulk/internal/email"
@@ -43,9 +43,10 @@ func (v *Validate) Start() {
 		for _, result := range results {
 			select {
 			case <-kill.KillCtx.Done():
+				master.Stop()
 				console.Warning("Unexpected shutdown while validating emails.")
 
-				os.Exit(1)
+				return errors.New("Shutdown")
 			default:
 				master.NewWork(func() {
 					result.ValidateEmail()
@@ -54,7 +55,6 @@ func (v *Validate) Start() {
 			}
 		}
 
-		// Returning an error will stop further batch processing
 		return nil
 	})
 	master.Wait()