stop using goroutines in TestPausedProvisionerProvision_waits

to render the test less flaky.

this should fix #7684

packer/provisioner_test.go

@@ -2,6 +2,7 @@ package packer
 
 import (
 	"context"
+	"fmt"
 	"testing"
 	"time"
 )
@@ -126,30 +127,29 @@ func TestPausedProvisionerProvision(t *testing.T) {
 }
 
 func TestPausedProvisionerProvision_waits(t *testing.T) {
-	mock := new(MockProvisioner)
+	startTime := time.Now()
+	waitTime := 50 * time.Millisecond
+
 	prov := &PausedProvisioner{
-		PauseBefore: 50 * time.Millisecond,
+		PauseBefore: waitTime,
-		Provisioner: mock,
+		Provisioner: &MockProvisioner{
+			ProvFunc: func(context.Context) error {
+				timeSinceStartTime := time.Since(startTime)
+				if timeSinceStartTime < waitTime {
+					return fmt.Errorf("Spent not enough time waiting: %s", timeSinceStartTime)
+				}
+				if timeSinceStartTime > waitTime+10*time.Millisecond {
+					return fmt.Errorf("Spent too much time waiting: %s", timeSinceStartTime)
+				}
+				return nil
+			},
+		},
 	}
 
-	dataCh := make(chan struct{})
+	err := prov.Provision(context.Background(), testUi(), new(MockCommunicator))
-	mock.ProvFunc = func(context.Context) error {
-		close(dataCh)
-		return nil
-	}
 
-	go prov.Provision(context.Background(), testUi(), new(MockCommunicator))
+	if err != nil {
-
+		t.Fatalf("prov failed: %v", err)
-	select {
-	case <-time.After(10 * time.Millisecond):
-	case <-dataCh:
-		t.Fatal("should not be called")
-	}
-
-	select {
-	case <-time.After(100 * time.Millisecond):
-		t.Fatal("never called")
-	case <-dataCh:
 	}
 }