Исходники и презентации

homework/contexts/homework_test.go

@@ -0,0 +1,74 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type Group struct {
+	// need to implement
+}
+
+func NewErrGroup(ctx context.Context) (*Group, context.Context) {
+	// need to implement
+	return &Group{}, ctx
+}
+
+func (g *Group) Go(action func() error) {
+	// need to implement
+}
+
+func (g *Group) Wait() error {
+	// need to implement
+	return nil
+}
+
+func TestErrGroupWithoutError(t *testing.T) {
+	var counter atomic.Int32
+	group, _ := NewErrGroup(context.Background())
+
+	for i := 0; i < 5; i++ {
+		group.Go(func() error {
+			time.Sleep(time.Second)
+			counter.Add(1)
+			return nil
+		})
+	}
+
+	err := group.Wait()
+	assert.Equal(t, int32(5), counter.Load())
+	assert.NoError(t, err)
+}
+
+func TestErrGroupWithError(t *testing.T) {
+	var counter atomic.Int32
+	group, ctx := NewErrGroup(context.Background())
+
+	for i := 0; i < 5; i++ {
+		group.Go(func() error {
+			timer := time.NewTimer(time.Second)
+			defer timer.Stop()
+
+			select {
+			case <-ctx.Done():
+				return ctx.Err()
+			case <-timer.C:
+				counter.Add(1)
+				return nil
+			}
+		})
+	}
+
+	group.Go(func() error {
+		return errors.New("error")
+	})
+
+	err := group.Wait()
+	assert.Equal(t, int32(0), counter.Load())
+	assert.Error(t, err)
+}