flipped some error messages that were wrong

buff.go

@@ -188,12 +188,12 @@ func (rb *Buff) getById(id int) (interface{}, error) {
 
 	// Check it's not before our first known id
 	if id < rb.oldest {
-		return nil, errors.Errorf("requested ID %d is lower than oldest id %d", id, rb.newest)
+		return nil, errors.Errorf("requested ID %d is lower than oldest id %d", id, rb.oldest)
 	}
 
 	// Check it's not after our last known id
 	if id > rb.newest {
-		return nil, errors.Errorf("requested id %d is higher than most recent id %d", id, rb.oldest)
+		return nil, errors.Errorf("requested id %d is higher than most recent id %d", id, rb.newest)
 	}
 
 	return rb.buff[id%rb.count], nil

buff_test.go

@@ -117,7 +117,7 @@ func TestBuff_Push(t *testing.T) {
 
 // Test ID upsert on ringbuff (bulk of cases)
 func TestBuff_UpsertById(t *testing.T) {
-	rb := setup()
+	rb := NewBuff(5)
 	v := 15
 	err := rb.UpsertById(v, &v)
 	if err != nil {
@@ -127,10 +127,11 @@ func TestBuff_UpsertById(t *testing.T) {
 		t.Error("Failed to get correct ID")
 	}
 
-	val, _ := rb.GetById(7)
+	val, err := rb.GetById(7)
 	if val != nil {
 		t.Errorf("Should have gotten nil value for id 7")
 	}
+	fmt.Println(err.Error())
 	v = 14
 	err = rb.UpsertById(v, &v)
 	if err != nil {