GO-3675: add error for nil value

Signed-off-by: AnastasiaShemyakinskaya <shem98a@mail.ru>

app/ocache/ocache.go

@@ -3,6 +3,7 @@ package ocache
 import (
 	"context"
 	"errors"
+	"fmt"
 	"sync"
 	"time"
 
@@ -167,6 +168,9 @@ func (c *oCache) load(ctx context.Context, id string, e *entry) {
 
 	c.mu.Lock()
 	defer c.mu.Unlock()
+	if value == nil {
+		err = fmt.Errorf("loaded value is nil, id: %s", id)
+	}
 	if err != nil {
 		e.loadErr = err
 		delete(c.data, id)
@@ -199,9 +203,7 @@ func (c *oCache) remove(ctx context.Context, e *entry) (ok bool, err error) {
 	_, curState := e.setClosing(true)
 	if curState == entryStateClosing {
 		ok = true
-		if e.value != nil {
 		err = e.value.Close()
-		}
 		c.mu.Lock()
 		e.setClosed()
 		delete(c.data, e.id)

app/ocache/ocache_test.go

@@ -140,24 +140,15 @@ func TestOCache_Get(t *testing.T) {
 		assert.Equal(t, context.Canceled, err)
 		assert.NoError(t, c.Close())
 	})
-	t.Run("parallel load and remove", func(t *testing.T) {
+	t.Run("value is nil", func(t *testing.T) {
-		var waitCh = make(chan struct{})
 		c := New(func(ctx context.Context, id string) (value Object, err error) {
 			return nil, nil
 		})
 
-		id := "id"
+		value, err := c.Get(ctx, "id")
-		go func() {
+		assert.NotNil(t, err)
-			val, err := c.Get(context.TODO(), id)
+		assert.Nil(t, value)
-			close(waitCh)
+		assert.NoError(t, c.Close())
-			require.NoError(t, err)
-			assert.Nil(t, val)
-		}()
-
-		<-waitCh
-		ok, err := c.Remove(context.TODO(), id)
-		require.NoError(t, err)
-		assert.True(t, ok)
 	})
 }